Context Navigation

faq-parse.html @ 358

Revision 358, 112.0 KB checked in by bittner, 19 years ago (diff)
xerces added

Line
1	<HTML><HEAD><META content="text/html; charset=utf8" http-equiv="Content-Type"><SCRIPT language="JavaScript" src="resources/script.js" type="text/javascript"></SCRIPT><TITLE>Programming/Parsing FAQs</TITLE></HEAD><BODY alink="#ff0000" bgcolor="#ffffff" leftmargin="4" link="#0000ff" marginheight="4" marginwidth="4" text="#000000" topmargin="4" vlink="#0000aa"><TABLE border="0" cellpadding="0" cellspacing="0" width="620"><TR><TD align="left" height="60" rowspan="3" valign="top" width="135"><IMG border="0" height="60" hspace="0" src="resources/logo.gif" vspace="0" width="135"></TD><TD align="left" colspan="4" height="5" valign="top" width="456"><IMG border="0" height="5" hspace="0" src="resources/line.gif" vspace="0" width="456"></TD><TD align="left" height="60" rowspan="3" valign="top" width="29"><IMG border="0" height="60" hspace="0" src="resources/right.gif" vspace="0" width="29"></TD></TR><TR><TD align="left" bgcolor="#0086b2" colspan="4" height="35" valign="top" width="456"><IMG alt="" border="0" height="35" hspace="0" src="graphics/faq-parse-header.jpg" vspace="0" width="456"></TD></TR><TR><TD align="left" height="20" valign="top" width="168"><IMG border="0" height="20" hspace="0" src="resources/bottom.gif" vspace="0" width="168"></TD><TD align="left" height="20" valign="top" width="96"><A href="http://xml.apache.org/" onMouseOut="rolloverOff('xml');" onMouseOver="rolloverOn('xml');" target="new"><IMG alt="http://xml.apache.org/" border="0" height="20" hspace="0" name="xml" onLoad="rolloverLoad('xml','resources/button-xml-hi.gif','resources/button-xml-lo.gif');" src="resources/button-xml-lo.gif" vspace="0" width="96"></A></TD><TD align="left" height="20" valign="top" width="96"><A href="http://www.apache.org/" onMouseOut="rolloverOff('asf');" onMouseOver="rolloverOn('asf');" target="new"><IMG alt="http://www.apache.org/" border="0" height="20" hspace="0" name="asf" onLoad="rolloverLoad('asf','resources/button-asf-hi.gif','resources/button-asf-lo.gif');" src="resources/button-asf-lo.gif" vspace="0" width="96"></A></TD><TD align="left" height="20" valign="top" width="96"><A href="http://www.w3.org/" onMouseOut="rolloverOff('w3c');" onMouseOver="rolloverOn('w3c');" target="new"><IMG alt="http://www.w3.org/" border="0" height="20" hspace="0" name="w3c" onLoad="rolloverLoad('w3c','resources/button-w3c-hi.gif','resources/button-w3c-lo.gif');" src="resources/button-w3c-lo.gif" vspace="0" width="96"></A></TD></TR></TABLE><TABLE border="0" cellpadding="0" cellspacing="0" width="620"><TR><TD align="left" valign="top" width="120"><IMG border="0" height="14" hspace="0" src="resources/join.gif" vspace="0" width="120"><BR>
2
3
4	<A href="../index.html" onMouseOut="rolloverOff('side-ext-2');" onMouseOver="rolloverOn('side-ext-2');"><IMG alt="Home" border="0" height="12" hspace="0" name="side-ext-2" onLoad="rolloverLoad('side-ext-2','graphics/ext-2-label-2.jpg','graphics/ext-2-label-3.jpg');" src="graphics/ext-2-label-3.jpg" vspace="0" width="120"></A><BR>
5
6
7
8	<IMG border="0" height="6" hspace="0" src="resources/separator.gif" vspace="0" width="120"><BR>
9
10	<A href="index.html" onMouseOut="rolloverOff('side-index');" onMouseOver="rolloverOn('side-index');"><IMG alt="Readme" border="0" height="12" hspace="0" name="side-index" onLoad="rolloverLoad('side-index','graphics/index-label-2.jpg','graphics/index-label-3.jpg');" src="graphics/index-label-3.jpg" vspace="0" width="120"></A><BR>
11	<A href="releases.html" onMouseOut="rolloverOff('side-releases');" onMouseOver="rolloverOn('side-releases');"><IMG alt="Release Info" border="0" height="12" hspace="0" name="side-releases" onLoad="rolloverLoad('side-releases','graphics/releases-label-2.jpg','graphics/releases-label-3.jpg');" src="graphics/releases-label-3.jpg" vspace="0" width="120"></A><BR>
12
13
14
15
16
17
18	<IMG border="0" height="6" hspace="0" src="resources/separator.gif" vspace="0" width="120"><BR>
19
20	<A href="install.html" onMouseOut="rolloverOff('side-install');" onMouseOver="rolloverOn('side-install');"><IMG alt="Installation" border="0" height="12" hspace="0" name="side-install" onLoad="rolloverLoad('side-install','graphics/install-label-2.jpg','graphics/install-label-3.jpg');" src="graphics/install-label-3.jpg" vspace="0" width="120"></A><BR>
21	<A href="http://xml.apache.org/xerces-c/download.cgi" onMouseOut="rolloverOff('side-ext-18');" onMouseOver="rolloverOn('side-ext-18');"><IMG alt="Download" border="0" height="12" hspace="0" name="side-ext-18" onLoad="rolloverLoad('side-ext-18','graphics/ext-18-label-2.jpg','graphics/ext-18-label-3.jpg');" src="graphics/ext-18-label-3.jpg" vspace="0" width="120"></A><BR>
22	<A href="build.html" onMouseOut="rolloverOff('side-build');" onMouseOver="rolloverOn('side-build');"><IMG alt="Build Instructions" border="0" height="12" hspace="0" name="side-build" onLoad="rolloverLoad('side-build','graphics/build-label-2.jpg','graphics/build-label-3.jpg');" src="graphics/build-label-3.jpg" vspace="0" width="120"></A><BR>
23
24
25
26
27	<IMG border="0" height="6" hspace="0" src="resources/separator.gif" vspace="0" width="120"><BR>
28
29	<A href="faqs.html" onMouseOut="rolloverOff('side-faqs');" onMouseOver="rolloverOn('side-faqs');"><IMG alt="FAQs" border="0" height="12" hspace="0" name="side-faqs" onLoad="rolloverLoad('side-faqs','graphics/faqs-label-2.jpg','graphics/faqs-label-3.jpg');" src="graphics/faqs-label-3.jpg" vspace="0" width="120"></A><BR>
30
31	<A href="samples.html" onMouseOut="rolloverOff('side-samples');" onMouseOver="rolloverOn('side-samples');"><IMG alt="Samples" border="0" height="12" hspace="0" name="side-samples" onLoad="rolloverLoad('side-samples','graphics/samples-label-2.jpg','graphics/samples-label-3.jpg');" src="graphics/samples-label-3.jpg" vspace="0" width="120"></A><BR>
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48	<A href="api.html" onMouseOut="rolloverOff('side-api');" onMouseOver="rolloverOn('side-api');"><IMG alt="API Docs" border="0" height="12" hspace="0" name="side-api" onLoad="rolloverLoad('side-api','graphics/api-label-2.jpg','graphics/api-label-3.jpg');" src="graphics/api-label-3.jpg" vspace="0" width="120"></A><BR>
49
50	<IMG border="0" height="6" hspace="0" src="resources/separator.gif" vspace="0" width="120"><BR>
51
52	<A href="ApacheDOMC++Binding.html" onMouseOut="rolloverOff('side-ext-68');" onMouseOver="rolloverOn('side-ext-68');"><IMG alt="DOM C++ Binding" border="0" height="12" hspace="0" name="side-ext-68" onLoad="rolloverLoad('side-ext-68','graphics/ext-68-label-2.jpg','graphics/ext-68-label-3.jpg');" src="graphics/ext-68-label-3.jpg" vspace="0" width="120"></A><BR>
53
54	<A href="program.html" onMouseOut="rolloverOff('side-program');" onMouseOver="rolloverOn('side-program');"><IMG alt="Programming" border="0" height="12" hspace="0" name="side-program" onLoad="rolloverLoad('side-program','graphics/program-label-2.jpg','graphics/program-label-3.jpg');" src="graphics/program-label-3.jpg" vspace="0" width="120"></A><BR>
55
56
57
58
59
60
61
62
63	<A href="migrate.html" onMouseOut="rolloverOff('side-migrate');" onMouseOver="rolloverOn('side-migrate');"><IMG alt="Migration Guide" border="0" height="12" hspace="0" name="side-migrate" onLoad="rolloverLoad('side-migrate','graphics/migrate-label-2.jpg','graphics/migrate-label-3.jpg');" src="graphics/migrate-label-3.jpg" vspace="0" width="120"></A><BR>
64
65
66	<IMG border="0" height="6" hspace="0" src="resources/separator.gif" vspace="0" width="120"><BR>
67
68	<A href="feedback.html" onMouseOut="rolloverOff('side-feedback');" onMouseOver="rolloverOn('side-feedback');"><IMG alt="Feedback" border="0" height="12" hspace="0" name="side-feedback" onLoad="rolloverLoad('side-feedback','graphics/feedback-label-2.jpg','graphics/feedback-label-3.jpg');" src="graphics/feedback-label-3.jpg" vspace="0" width="120"></A><BR>
69	<A href="bug-report.html" onMouseOut="rolloverOff('side-bug-report');" onMouseOver="rolloverOn('side-bug-report');"><IMG alt="Bug-Reporting" border="0" height="12" hspace="0" name="side-bug-report" onLoad="rolloverLoad('side-bug-report','graphics/bug-report-label-2.jpg','graphics/bug-report-label-3.jpg');" src="graphics/bug-report-label-3.jpg" vspace="0" width="120"></A><BR>
70	<A href="pdf.html" onMouseOut="rolloverOff('side-pdf');" onMouseOver="rolloverOn('side-pdf');"><IMG alt="PDF Document" border="0" height="12" hspace="0" name="side-pdf" onLoad="rolloverLoad('side-pdf','graphics/pdf-label-2.jpg','graphics/pdf-label-3.jpg');" src="graphics/pdf-label-3.jpg" vspace="0" width="120"></A><BR>
71
72	<IMG border="0" height="6" hspace="0" src="resources/separator.gif" vspace="0" width="120"><BR>
73
74
75	<A href="http://xml.apache.org/websrc/cvsweb.cgi/xml-xerces/c/" onMouseOut="rolloverOff('side-ext-100');" onMouseOver="rolloverOn('side-ext-100');"><IMG alt="CVS Repository" border="0" height="12" hspace="0" name="side-ext-100" onLoad="rolloverLoad('side-ext-100','graphics/ext-100-label-2.jpg','graphics/ext-100-label-3.jpg');" src="graphics/ext-100-label-3.jpg" vspace="0" width="120"></A><BR>
76
77
78	<A href="http://marc.theaimsgroup.com/?l=xerces-c-dev" onMouseOut="rolloverOff('side-ext-102');" onMouseOver="rolloverOn('side-ext-102');"><IMG alt="Mail Archive" border="0" height="12" hspace="0" name="side-ext-102" onLoad="rolloverLoad('side-ext-102','graphics/ext-102-label-2.jpg','graphics/ext-102-label-3.jpg');" src="graphics/ext-102-label-3.jpg" vspace="0" width="120"></A><BR>
79
80
81	<IMG border="0" height="14" hspace="0" src="resources/close.gif" vspace="0" width="120"><BR></TD><TD align="left" valign="top" width="500"><TABLE border="0" cellpadding="3" cellspacing="0"><TR><TD><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Questions</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif"><UL><LI><A href="#faq-1">Does Xerces-C++ support Schema?</A></LI><LI><A href="#faq-2">Why Xerces-C++ does not support this particular Schema feature?</A></LI><LI><A href="#faq-3">Why does my application crash when instantiating the parser?</A></LI><LI><A href="#faq-4">Is it OK to call the XMLPlatformUtils::Initialize/Terminate pair of routines multiple times in one program?</A></LI><LI><A href="#faq-5">Why does my application crash or hang if XMLPlatformUtils::Initialize()/Terminate() pair is called more than once?</A></LI><LI><A href="#faq-6">Why does my application crash after calling XMLPlatformUtils::Terminate()?</A></LI><LI><A href="#faq-7">I'm suddenly getting segfaults with Xerces-C 2.3.0; why might this be?</A></LI><LI><A href="#faq-8">Is Xerces-C++ thread-safe?</A></LI><LI><A href="#faq-9">I am seeing memory leaks in Xerces-C++. Are they real?</A></LI><LI><A href="#faq-10">I find memory leaks in Xerces-C++. How do I eliminate it?</A></LI><LI><A href="#faq-11">Can Xerces-C++ create an XML skeleton based on a DTD</A></LI><LI><A href="#faq-12">Can I use Xerces-C++ to perform write validation</A></LI><LI><A href="#faq-13">Can I validate the data contained in a DOM tree?</A></LI><LI><A href="#faq-14">How to write out a DOM tree into a string or an XML file?</A></LI><LI><A href="#faq-15">Why does DOMNode::cloneNode() not clone the pointer assigned to a DOMNode via DOMNode::setUserData()?</A></LI><LI><A href="#faq-16">How are entity reference nodes handled in DOM?</A></LI><LI><A href="#faq-17">What kinds of URLs are currently supported in Xerces-C++?</A></LI><LI><A href="#faq-18">How can I add support for URLs with HTTP/FTP protocols?</A></LI><LI><A href="#faq-19">Can I use Xerces-C++ to parse HTML?</A></LI><LI><A href="#faq-20">I keep getting an error: "invalid UTF-8 character". What's wrong?</A></LI><LI><A href="#faq-21">What encodings are supported by Xerces-C / XML4C?</A></LI><LI><A href="#faq-22">What character encoding should I use when creating XML documents?</A></LI><LI><A href="#faq-23">Is EBCDIC supported?</A></LI><LI><A href="#faq-24">Why does deleting a transcoded string result in assertion on windows?</A></LI><LI><A href="#faq-25">How do I transcode to/from something besides the local code page?</A></LI><LI><A href="#faq-26">Why does setProperty not work?</A></LI><LI><A href="#faq-27">Why does getProperty not work?</A></LI><LI><A href="#faq-28">Why does the parser still try to locate the DTD even validation is turned off and how to ignore external DTD reference?</A></LI><LI><A href="#faq-29">Why do I get segmentation fault when running on Redhat Linux?</A></LI><LI><A href="#faq-30">Why does the XML data generated by the DOMWriter does not match my original XML input?</A></LI><LI><A href="#faq-31">Why does my application crash when deleting the parser after releasing a document?</A></LI><LI><A href="#faq-32">Why do we have two versions of some XMLString methods (one with memory manager and one without)?</A></LI></UL></FONT></TD></TR></TABLE><BR><BR><A name="faq-1"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B> Does Xerces-C++ support Schema?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
82
83	<P>Yes. The Xerces-C++ 2.6.0 contains an implementation
84	of the W3C XML Schema Language, a recommendation of the Worldwide Web Consortium
85	available in three parts:
86	<A href="http://www.w3.org/TR/xmlschema-0/">XML Schema: Primer</A> and
87	<A href="http://www.w3.org/TR/xmlschema-1/">XML Schema: Structures</A> and
88	<A href="http://www.w3.org/TR/xmlschema-2/">XML Schema: Datatypes</A>.
89	We consider this implementation complete. See
90	<A href="schema.html#limitation">the Schema page</A> for limitations.</P>
91
92	</FONT></TD></TR></TABLE><BR><A name="faq-2"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B> Why Xerces-C++ does not support this particular Schema feature?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
93
94	<P>The Xerces-C++ 2.6.0 contains an implementation
95	of the W3C XML Schema Language, a recommendation of the Worldwide Web Consortium
96	available in three parts:
97	<A href="http://www.w3.org/TR/xmlschema-0/">XML Schema: Primer</A> and
98	<A href="http://www.w3.org/TR/xmlschema-1/">XML Schema: Structures</A> and
99	<A href="http://www.w3.org/TR/xmlschema-2/">XML Schema: Datatypes</A>.
100	We consider this implementation complete. See
101	<A href="schema.html#limitation">the Schema page</A> for limitations.</P>
102
103	<P>If you find any Schema feature which is specified in the W3C XML Schema Language
104	Recommendation does not work with Xerces-C++ 2.6.0, we encourage
105	the submission of bugs as described in
106	<A href="bug-report.html">Bug Reporting</A> page.
107	</P>
108
109	</FONT></TD></TR></TABLE><BR><A name="faq-3"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why does my application crash when instantiating the parser?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
110
111	<P>In order to work with the Xerces-C++ parser, you have to first
112	initialize the XML subsystem. The most common mistake is to forget this
113	initialization. Before you make any calls to Xerces-C++ APIs, you must
114	call XMLPlatformUtils::Initialize(): </P>
115
116	<DIV align="left"><TABLE border="0" cellpadding="0" cellspacing="4" width="464"><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#ffffff" width="462"><FONT size="-1"><PRE>
117	try {
118	XMLPlatformUtils::Initialize();
119	}
120	catch (const XMLException& toCatch) {
121	// Do your failure processing here
122	}</PRE></FONT></TD><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></DIV>
123
124	<P>This initializes the Xerces system and sets its internal
125	variables. Note that you must the include <CODE><FONT face="courier, monospaced">xercesc/util/PlatformUtils.hpp</FONT></CODE> file for this to work.</P>
126
127	</FONT></TD></TR></TABLE><BR><A name="faq-4"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Is it OK to call the XMLPlatformUtils::Initialize/Terminate pair of routines multiple times in one program?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
128	<P>Yes. Since Xerces-C++ 1.5.2, the code has been enhanced so that
129	calling XMLPlatformUtils::Initialize/Terminate pair of routines
130	multiple times in one process is now allowed.
131	</P>
132
133	<P>But the application needs to guarantee that only one thread has entered either the
134	method XMLPlatformUtils::Initialize() or the method XMLPlatformUtils::Terminate() at any
135	one time.</P>
136
137	<P>If you are calling XMLPlatformUtils::Initialize() a number of times, and then follow with
138	XMLPlatformUtils::Terminate() the same number of times, only the first XMLPlatformUtils::Initialize()
139	will do the initialization, and only the last XMLPlatformUtils::Terminate() will clean up
140	the memory. The other calls are ignored.
141	</P>
142
143	<P>To ensure all the memory held by the parser are freed, the number of XMLPlatformUtils::Terminate() calls
144	should match the number of XMLPlatformUtils::Initialize() calls.
145	</P>
146
147	<P>
148	Consider the following code snippets (for illustration simplicity the following
149	sample code is not coded in try/catch clause):
150	</P>
151
152	<DIV align="left"><TABLE border="0" cellpadding="0" cellspacing="4" width="464"><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#ffffff" width="462"><FONT size="-1"><PRE>
153	// The XMLPlatformUtils::Initialize/Terminate calls are paired.
154	{
155	// Initialize the parser
156	XMLPlatformUtils::Initialize();
157
158	SAXParser* parser = new SAXParser;
159	parser->parse(xmlFile);
160	delete parser;
161
162	// Free all memory that was being held by the parser
163	XMLPlatformUtils::Terminate();
164
165	// Initialize the parser
166	XMLPlatformUtils::Initialize();
167
168	parser = new SAXParser;
169	parser->parse(xmlFile);
170	delete parser;
171
172	// Free all memory that was being held by the parser
173	XMLPlatformUtils::Terminate();
174	}
175	</PRE></FONT></TD><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></DIV>
176
177	<DIV align="left"><TABLE border="0" cellpadding="0" cellspacing="4" width="464"><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#ffffff" width="462"><FONT size="-1"><PRE>
178	// calls XMLPlatformUtils::Initialize() three times
179	// then calls XMLPlatformUtils::Terminate() numerous times
180	{
181	// Initialize the parser
182	XMLPlatformUtils::Initialize();
183
184	// The next two calls are no-op
185	XMLPlatformUtils::Initialize();
186	XMLPlatformUtils::Initialize();
187
188	SAXParser* parser = new SAXParser;
189	parser->parse(xmlFile);
190	delete parser;
191
192	// The first two XMLPlatformUtils::Terminate() calls are no-op
193	XMLPlatformUtils::Terminate();
194	XMLPlatformUtils::Terminate();
195
196	// This third XMLPlatformUtils::Terminate() will free all memory that was being held by the parser
197	XMLPlatformUtils::Terminate();
198
199	// This extra fourth XMLPlatformUtils::Terminate() call is no-op.
200	// However calling XMLPlatformUtils::Terminate() without a matching XMLPlatformUtils::Initialize()
201	// is dangerous and should be avoided.
202	XMLPlatformUtils::Terminate();
203	}
204	</PRE></FONT></TD><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></DIV>
205	</FONT></TD></TR></TABLE><BR><A name="faq-5"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why does my application crash or hang if XMLPlatformUtils::Initialize()/Terminate() pair is called more than once?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
206
207	<P>Please make sure you are using the Xerces-C++ 1.5.2 or up.
208	</P>
209
210	<P>Earlier version of Xerces-C++ does not allow XMLPlatformUtils::Initialize()/Terminate()
211	pair to be called more than once or has a problem.
212	</P>
213
214	</FONT></TD></TR></TABLE><BR><A name="faq-6"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why does my application crash after calling XMLPlatformUtils::Terminate()?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
215
216	<P>Please make sure the XMLPlatformUtils::Terminate() is the last Xerces-C++ function to be called
217	in your program. NO explicit nor implicit Xerces-C++ destructor (those local data that are
218	destructed when going out of scope) should be called after XMLPlatformUtils::Terminate().
219	</P>
220	<P>
221	For example consider the following code snippets which is incorrect
222	(for illustration simplicity the following sample code is not coded in try/catch clause):
223	</P>
224
225	<DIV align="left"><TABLE border="0" cellpadding="0" cellspacing="4" width="464"><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#ffffff" width="462"><FONT size="-1"><PRE>
226	1: {
227	2: XMLPlatformUtils::Initialize();
228	3: DOMString c("hello");
229	4: XMLPlatformUtils::Terminate();
230	5: }
231	</PRE></FONT></TD><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></DIV>
232
233	<P>The DOMString object "c" is destructed when going out of scope at line 5 before the closing
234	brace. As a result, DOMString destructor is called at line 5 after
235	XMLPlatformUtils::Terminate() which is wrong. Correct code should be:
236	</P>
237
238	<DIV align="left"><TABLE border="0" cellpadding="0" cellspacing="4" width="464"><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#ffffff" width="462"><FONT size="-1"><PRE>
239	1: {
240	2: XMLPlatformUtils::Initialize();
241	2a: {
242	3: DOMString c("hello");
243	3a: }
244	4: XMLPlatformUtils::Terminate();
245	5: }
246	</PRE></FONT></TD><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></DIV>
247
248	<P>The extra pair of braces (line 2a and 3a) ensures that all implicit destructors are called
249	before terminating Xerces-C++.</P>
250
251	<P>In addition the application also needs to guarantee that only one thread has entered either the
252	method XMLPlatformUtils::Initialize() or the method XMLPlatformUtils::Terminate() at any
253	one time.
254	</P>
255	</FONT></TD></TR></TABLE><BR><A name="faq-7"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>I'm suddenly getting segfaults with Xerces-C 2.3.0;
256	why might this be?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
257	<P>The introduction of pluggable memory management into
258	Xerces-C, one of the main features of 2.3.0, means that
259	application writers have to be more conscious about
260	destructors being invoked implicitly after a call to
261	XMLPlatformUtils::Terminate(). For example, the
262	following code is guaranteed to produce a segmentation
263	fault under Xerces-C 2.3.0, while it happened to work
264	under previous versions (in fact, this was how our
265	SAXPrint sample was formerly written;
266	try-catch blocks removed for brevity):
267	</P>
268	<DIV align="left"><TABLE border="0" cellpadding="0" cellspacing="4" width="464"><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#ffffff" width="462"><FONT size="-1"><PRE>
269	void myParsingFunction()
270	{
271	XMLPlatformUtils::Initialize();
272	SAXParser parser;
273	//parser.various method calls
274	XMLPlatformUtils::Terminate();
275	} // seg fault here!
276	</PRE></FONT></TD><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></DIV>
277	<P>The reason this will produce a segmentation fault is
278	that any dynamic memory the SAXParser (or any other of
279	Xerces's parsers) needs to allocate is now allocated
280	by default by a static object owned by XMLPlatformUtils.
281	When the XMLPlatformUtils::Terminate() call is made, this
282	object is destroyed--and, consequently, so are all the
283	objects that it directly created. This includes all the
284	objects dynamically allocated by the SAXParser. When the
285	parser object goes out of scope, its destructor is
286	invoked, and this attempts to destroy all the objects
287	that it created--which have of course just been destroyed
288	by the static MemoryManager in XMLPlatformUtils.
289	</P>
290	<P>
291	To avoid this, one must either explicitly scope the
292	parser object inside calls to
293	XMLPlatformUtils::Initialize() and
294	XMLPlatformUtils::Terminate(), or dynamically allocate
295	the parser object and destroy it explicitly before the
296	call to XMLPlatformUtils::Terminate() is made.
297	</P>
298	<P>Another way of producing segmentation faults--that again,
299	unfortunately, was employed by some of our
300	samples--is to have calls to XMLPlatformUtils::Terminate()
301	in a catch block that catches any of Xerces's exceptions.
302	Since the destructor of the exception will implicitly be
303	invoked upon exit from the catch block, and since some of
304	the exceptions' destructors call on Xerces's
305	default memory manager to destroy dynamically-allocated
306	objects, their destruction will provoke a segmentation
307	fault even if a return statement is placed in the catch
308	block since the default memory manager will no longer exist.
309	This practice is now avoided in all our samples.
310	</P>
311	</FONT></TD></TR></TABLE><BR><A name="faq-8"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Is Xerces-C++ thread-safe?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
312
313	<P>This is not a question that has a simple yes/no answer. Here are the
314	rules for using Xerces-C++ in a multi-threaded environment:</P>
315
316	<P>Within an address space, an instance of the parser may be used without
317	restriction from a single thread, or an instance of the parser can be accessed
318	from multiple threads, provided the application guarantees that only one thread
319	has entered a method of the parser at any one time.</P>
320
321	<P>When two or more parser instances exist in a process, the instances can
322	be used concurrently, without external synchronization. That is, in an
323	application containing two parsers and two threads, one parser can be running
324	within the first thread concurrently with the second parser running within the
325	second thread.</P>
326
327	<P>The same rules apply to Xerces-C++ DOM documents. Multiple document
328	instances may be concurrently accessed from different threads, but any given
329	document instance can only be accessed by one thread at a time.</P>
330
331	<P>DOMStrings allow multiple concurrent readers. All DOMString const
332	methods are thread safe, and can be concurrently entered by multiple threads.
333	Non-const DOMString methods, such as <CODE><FONT face="courier, monospaced">appendData()</FONT></CODE>, are not thread safe and the application must guarantee that no other
334	methods (including const methods) are executed concurrently with them.</P>
335
336	<P>The application also needs to guarantee that only one thread has entered either the
337	method XMLPlatformUtils::Initialize() or the method XMLPlatformUtils::Terminate() at any
338	one time.</P>
339
340	</FONT></TD></TR></TABLE><BR><A name="faq-9"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>I am seeing memory leaks in Xerces-C++. Are they real?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
341
342	<P>The Xerces-C++ library allocates and caches some commonly reused
343	items. The storage for these may be reported as memory leaks by some heap
344	analysis tools; to avoid the problem, call the function <CODE><FONT face="courier, monospaced">XMLPlatformUtils::Terminate()</FONT></CODE> before your application exits. This will free all memory that was being
345	held by the library.</P>
346
347	<P>For most applications, the use of <CODE><FONT face="courier, monospaced">Terminate()</FONT></CODE> is optional. The system will recover all memory when the application
348	process shuts down. The exception to this is the use of Xerces-C++ from DLLs
349	that will be repeatedly loaded and unloaded from within the same process. To
350	avoid memory leaks with this kind of use, <CODE><FONT face="courier, monospaced">Terminate()</FONT></CODE> must be called before unloading the Xerces-C++ library</P>
351
352	<P>To ensure all the memory held by the parser are freed, the number of XMLPlatformUtils::Terminate() calls
353	should match the number of XMLPlatformUtils::Initialize() calls.
354	</P>
355
356	<P>If you are using XML4C where ICU is used, you may call ICU function u_cleanup() to clean up
357	ICU static data. Please see <A href="http://oss.software.ibm.com/icu/">ICU documentation</A>
358	for details.
359	</P>
360	</FONT></TD></TR></TABLE><BR><A name="faq-10"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>I find memory leaks in Xerces-C++. How do I eliminate it?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
361
362	<P>The "leaks" that are reported through a leak-detector or heap-analysis
363	tools aren't really leaks in most application, in that the memory usage does
364	not grow over time as the XML parser is used and re-used.</P>
365
366	<P>What you are seeing as leaks are actually lazily evaluated data
367	allocated into static variables. This data gets released when the application
368	ends. You can make a call to <CODE><FONT face="courier, monospaced">XMLPlatformUtil::terminate()</FONT></CODE> to release all the lazily allocated variables before you exit your
369	program.</P>
370
371	<P>To ensure all the memory held by the parser are freed, the number of XMLPlatformUtils::Terminate() calls
372	should match the number of XMLPlatformUtils::Initialize() calls.
373	</P>
374
375	<P>If you are using XML4C where ICU is used, you may call ICU function u_cleanup() to clean up
376	ICU static data. Please see <A href="http://oss.software.ibm.com/icu/">ICU documentation</A>
377	for details.
378	</P>
379	</FONT></TD></TR></TABLE><BR><A name="faq-11"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Is there a function that I have totally missed that creates
380	an XML file from a DTD, (obviously with the values missing, a skeleton, as it
381	were)?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
382
383	<P>No. This is not supported.</P>
384
385	</FONT></TD></TR></TABLE><BR><A name="faq-12"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Can I use Xerces-C++ to perform "write validation" (which is having an
386	appropriate Grammar and being able to add elements to the DOM whilst validating
387	against the grammar)?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
388
389	<P>No. This is not supported.</P>
390
391	<P>The best you can do for now is to create the DOM document, write it back
392	as XML and re-parse it.</P>
393
394	</FONT></TD></TR></TABLE><BR><A name="faq-13"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Is there a facility in Xerces-C++ to validate the data contained in a
395	DOM tree? That is, without saving and re-parsing the source document?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
396
397	<P>No. The best option for now is to generate XML source from the DOM and feed that back
398	into the parser.</P>
399
400	</FONT></TD></TR></TABLE><BR><A name="faq-14"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>How to write out a DOM tree into a string or an XML file?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
401	<P>Please make sure you are using Xerces-C++ 2.6.0 or up.</P>
402
403	<P>You can use
404	the DOMWriter::writeToString, or DOMWriter::writeNode to serialize a DOM tree.
405	Please refer to the sample DOMPrint or the API documentation for more details of
406	DOMWriter.</P>
407	</FONT></TD></TR></TABLE><BR><A name="faq-15"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why does DOMNode::cloneNode() not clone the pointer assigned to a DOMNode via DOMNode::setUserData()?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
408	<P>Xerces-C++ supports the DOMNode::userData specified
409	in <A href="http://www.w3.org/TR/2003/WD-DOM-Level-3-Core-20030226/DOM3-Core.html#core-ID-3A0ED0A4">
410	the DOM level 3 Node interface</A>. As
411	is made clear in the description of the behaviour of
412	<CODE><FONT face="courier, monospaced">cloneNode()</FONT></CODE>, userData that has been set on the
413	Node is not cloned. Thus, if the userData is to be copied
414	to the new Node, this copy must be effected manually.
415	Note further that the operation of <CODE><FONT face="courier, monospaced">importNode()</FONT></CODE>
416	is specified similarly.
417	</P>
418	</FONT></TD></TR></TABLE><BR><A name="faq-16"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>How are entity reference nodes handled in DOM?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
419
420	<P>If you are using the native DOM classes, the function <CODE><FONT face="courier, monospaced">setCreateEntityReferenceNodes</FONT></CODE>
421	controls how entities appear in the DOM tree. When
422	setCreateEntityReferenceNodes is set to true (the default), an occurrence of an
423	entity reference in the XML document will be represented by a subtree with an
424	EntityReference node at the root whose children represent the entity expansion.
425	Entity expansion will be a DOM tree representing the structure of the entity
426	expansion, not a text node containing the entity expansion as text.</P>
427
428	<P>If setCreateEntityReferenceNodes is false, an entity reference in the XML
429	document is represented by only the nodes that represent the entity expansion.
430	The DOM tree will not contain any entityReference nodes.</P>
431
432	</FONT></TD></TR></TABLE><BR><A name="faq-17"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>What kinds of URLs are currently supported in Xerces-C++?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
433
434	<P>The <CODE><FONT face="courier, monospaced">XMLURL</FONT></CODE> class provides for limited URL support. It understands the <CODE><FONT face="courier, monospaced">file://, http://</FONT></CODE>, and <CODE><FONT face="courier, monospaced">ftp://</FONT></CODE> URL types, and is capable or parsing them into their constituent
435	components, and normalizing them. It also supports the commonly required action
436	of conglomerating a base and relative URL into a single URL. In other words, it
437	performs the limited set of functions required by an XML parser.</P>
438
439	<P>Another thing that URLs commonly do are to create an input stream that
440	provides access to the entity referenced. The parser, as shipped, only supports
441	this functionality on URLs in the form <CODE><FONT face="courier, monospaced">file:///</FONT></CODE> and <CODE><FONT face="courier, monospaced">file://localhost/</FONT></CODE>, i.e. only when the URL refers to a local file.</P>
442
443	<P>You may enable support for HTTP and FTP URLs by implementing and
444	installing a NetAccessor object. When a NetAccessor object is installed, the
445	URL class will use it to create input streams for the remote entities referred
446	to by such URLs.</P>
447
448	</FONT></TD></TR></TABLE><BR><A name="faq-18"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>How can I add support for URLs with HTTP/FTP protocols?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
449
450	<P>Support for the http: protocol is now included by default on all
451	platforms.</P>
452
453	<P>To address the need to make remote connections to resources specified
454	using additional protocols, ftp for example, Xerces-C++ provides the <CODE><FONT face="courier, monospaced">NetAccessor</FONT></CODE> interface. The header file is <CODE><FONT face="courier, monospaced">src/xercesc/util/XMLNetAccessor.hpp</FONT></CODE>. This interface allows you to plug in your own implementation of URL
455	networking code into the Xerces-C++ parser.</P>
456
457	</FONT></TD></TR></TABLE><BR><A name="faq-19"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Can I use Xerces-C++ to parse HTML?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
458
459	<P>Yes, but only if the HTML follows the rules given in the
460	<A href="http://www.w3.org/TR/REC-xml">XML specification</A>. Most HTML,
461	however, does not follow the XML rules, and will generate XML well-formedness
462	errors.</P>
463
464	</FONT></TD></TR></TABLE><BR><A name="faq-20"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>I keep getting an error: "invalid UTF-8 character". What's wrong?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
465
466	<P>Most commonly, the XML <CODE><FONT face="courier, monospaced">encoding =</FONT></CODE> declaration is either incorrect or missing. Without a declaration, XML
467	defaults to the use utf-8 character encoding, which is not compatible with the
468	default text file encoding on most systems.</P>
469
470	<P>The XML declaration should look something like this:</P>
471
472	<P><CODE><FONT face="courier, monospaced"><?xml version="1.0" encoding="iso-8859-1"?></FONT></CODE></P>
473
474	<P>Make sure to specify the encoding that is actually used by file. The
475	encoding for "plain" text files depends both on the operating system and the
476	locale (country and language) in use.</P>
477
478	<P>Another common source of problems is that some characters are not
479	allowed in XML documents, according to the XML spec. Typical disallowed
480	characters are control characters, even if you escape them using the Character
481	Reference form. See the <A href="http://www.w3.org/TR/REC-xml#charsets">XML
482	spec</A>, sections 2.2 and 4.1 for details. If the parser is generating an <CODE><FONT face="courier, monospaced">Invalid character (Unicode: 0x???)</FONT></CODE> error, it is very likely that there's a character in there that you
483	can't see. You can generally use a UNIX command like "od -hc" to find it.</P>
484
485	</FONT></TD></TR></TABLE><BR><A name="faq-21"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>What encodings are supported by Xerces-C / XML4C?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
486
487	<P>Xerces-C has intrinsic support for ASCII, UTF-8, UTF-16 (Big/Small
488	Endian), UCS4 (Big/Small Endian), EBCDIC code pages IBM037, IBM1047 and IBM1140
489	encodings, ISO-8859-1 (aka Latin1) and Windows-1252. This means that it can
490	parse input XML files in these above mentioned encodings.</P>
491
492	<P>XML4C -- the version of Xerces-C available from IBM -- combines Xerces-C
493	and <A href="http://oss.software.ibm.com/icu/">
494	International Components for Unicode (ICU)</A> and
495	extends the encoding support to over 100 different encodings that are allowed
496	by ICU. In particular, all the encodings registered with the
497	<A href="http://www.iana.org/assignments/character-sets">
498	Internet Assigned Numbers Authority (IANA) </A> are supported in XML4C.</P>
499
500	<P>Some implementations or ports of Xerces-C provide support for
501	additional encodings. The exact set will depend on the supplier of the parser
502	and on the character set transcoding services in use.</P>
503
504	</FONT></TD></TR></TABLE><BR><A name="faq-22"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>What character encoding should I use when creating XML documents?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
505
506	<P>The best choice in most cases is either utf-8 or utf-16. Advantages of
507	these encodings include:</P>
508
509	<UL>
510	<LI>The best portability. These encodings are more widely supported by
511	XML processors than any others, meaning that your documents will have the best
512	possible chance of being read correctly, no matter where they end up.</LI>
513	<LI>Full international character support. Both utf-8 and utf-16 cover the
514	full Unicode character set, which includes all of the characters from all major
515	national, international and industry character sets.</LI>
516	<LI>Efficient. utf-8 has the smaller storage requirements for documents
517	that are primarily composed of characters from the Latin alphabet. utf-16 is
518	more efficient for encoding Asian languages. But both encodings cover all
519	languages without loss.</LI>
520	</UL>
521
522	<P>The only drawback of utf-8 or utf-16 is that they are not the native
523	text file format for most systems, meaning that common text file editors and
524	viewers can not be directly used.</P>
525
526	<P>A second choice of encoding would be any of the others listed in the
527	table above. This works best when the xml encoding is the same as the default
528	system encoding on the machine where the XML document is being prepared,
529	because the document will then display correctly as a plain text file. For UNIX
530	systems in countries speaking Western European languages, the encoding will
531	usually be iso-8859-1.</P>
532
533	<P>The versions of Xerces distributed by IBM, both C and Java (known
534	respectively as XML4C and XML4J), include all of the encodings listed in the
535	above table, on all platforms.</P>
536
537	<P>A word of caution for Windows users: The default character set on
538	Windows systems is windows-1252, not iso-8859-1. While Xerces-C++ does
539	recognize this Windows encoding, it is a poor choice for portable XML data
540	because it is not widely recognized by other XML processing tools. If you are
541	using a Windows-based editing tool to generate XML, check which character set
542	it generates, and make sure that the resulting XML specifies the correct name
543	in the <CODE><FONT face="courier, monospaced">encoding="..."</FONT></CODE> declaration.</P>
544
545	</FONT></TD></TR></TABLE><BR><A name="faq-23"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Is EBCDIC supported?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
546
547	<P>Yes, Xerces-C++ supports EBCDIC with the ibm1140, ibm037 and ibm1047 encodings.
548	When creating EBCDIC encoded XML data, the preferred encoding is ibm1140. The ibm037 encoding,
549	and its alternate name, ebcdic-cp-us, is almost the same as ibm1140, but
550	it lacks the Euro symbol.</P>
551
552	<P>These three encodings, ibm1140, ibm037 and ibm1047, are available on both
553	Xerces-C and IBM XML4C, on all platforms.</P>
554
555	<P>On IBM System 390, XML4C also supports three alternative forms,
556	ibm037-s390, ibm1140-s390, and ibm1047-s390. These are similar to the base ibm037, ibm1140, and ibm1047
557	encodings, but with alternate mappings of the EBCDIC new-line character, which
558	allows them to appear as normal text files on System 390. These encodings are
559	not supported on other platforms, and should not be used for portable data.</P>
560
561	<P>XML4C on System 390 and AS/400 also provides additional EBCDIC
562	encodings, including those for the character sets of different countries. The
563	exact set supported will be platform dependent, and these encodings are not
564	recommended for portable XML data.</P>
565
566	</FONT></TD></TR></TABLE><BR><A name="faq-24"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why does deleting a transcoded string result in assertion on windows?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
567	<P>Both your application program and the Xerces-C++ DLL must use the same DLL version of the
568	runtime library. If either statically links to the runtime library, the
569	problem will still occur.</P>
570
571	<P>For example, for a Win32/VC6 build, the runtime library build setting MUST
572	be "Multithreaded DLL" for release builds and "Debug Multithreaded DLL" for
573	debug builds.</P>
574
575	<P>Or for example for a Win32/BCB6 build, application need to switch to Multithreaded
576	runtime to avoid such memory access violation.</P>
577
578	<P>To bypass such problem, instead of calling operator delete[] directly, you can use the
579	provided function XMLString::release to delete any string that was allocated by the parser.
580	This will ensure the string is allocated and deleted by the same DLL and such assertion
581	problem should be resolved.</P>
582	</FONT></TD></TR></TABLE><BR><A name="faq-25"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>How do I transcode to/from something besides the local code page?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
583	<P>XMLString::transcode() will transcode from XMLCh to the local code page, and
584	other APIs which take a char* assume that the source text is in the local
585	code page. If this is not true, you must transcode the text yourself. You
586	can do this using local transcoding support on your OS, such as Iconv on
587	Unix or IBM's ICU package. However, if your transcoding needs are simple,
588	you can achieve some better portability by using the Xerces-C++ parser's
589	transcoder wrappers. You get a transcoder like this:
590	</P>
591	<UL>
592	<LI>
593	Call XMLPlatformUtils::fgTransServer->MakeNewTranscoderFor() and provide
594	the name of the encoding you wish to create a transcoder for. This will
595	return a transcoder to you, which you own and must delete when you are
596	through with it.
597
598	NOTE: You must provide a maximum block size that you will pass to the transcoder
599	at one time, and you must pass blocks of characters of this count or smaller when
600	you do your transcoding. The reason for this is that this is really an
601	internal API and is used by the parser itself to do transcoding. The parser
602	always does transcoding in known block sizes, and this allows transcoders to
603	be much more efficient for internal use since it knows the max size it will
604	ever have to deal with and can set itself up for that internally. In
605	general, you should stick to block sizes in the 4 to 64K range.
606	</LI>
607	<LI>
608	The returned transcoder is something derived from XMLTranscoder, so they
609	are all returned to you via that interface.
610	</LI>
611	<LI>
612	This object is really just a wrapper around the underlying transcoding
613	system actually in use by your version of Xerces, and does whatever is
614	necessary to handle differences between the XMLCh representation and the
615	representation used by that underlying transcoding system.
616	</LI>
617	<LI>
618	The transcoder object has two primary APIs, transcodeFrom() and
619	transcodeTo(). These transcode between the XMLCh format and the encoding you
620	indicated.
621	</LI>
622	<LI>
623	These APIs will transcode as much of the source data as will fit into the
624	outgoing buffer you provide. They will tell you how much of the source they
625	ate and how much of the target they filled. You can use this information to
626	continue the process until all source is consumed.
627	</LI>
628	<LI>
629	char* data is always dealt with in terms of bytes, and XMLCh data is
630	always dealt with in terms of characters. Don't mix up which you are dealing
631	with or you will not get the correct results, since many encodings don't
632	have a one to one relationship of characters to bytes.
633	</LI>
634	<LI>
635	When transcoding from XMLCh to the target encoding, the transcodeTo()
636	method provides an 'unrepresentable flag' parameter, which tells the
637	transcoder how to deal with an XMLCh code point that cannot be converted
638	legally to the target encoding, which can easily happen since XMLCh is
639	Unicode and can represent thousands of code points. The options are to use a
640	default replacement character (which the underlying transcoding service will
641	choose, and which is guaranteed to be legal for the target encoding), or to
642	throw an exception.
643	</LI>
644	</UL>
645	<P>Here is an example:</P>
646	<DIV align="left"><TABLE border="0" cellpadding="0" cellspacing="4" width="464"><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#ffffff" width="462"><FONT size="-1"><PRE>
647	// create an XMLTranscoder that is able to transcode between Unicode and Big5
648	// ASSUMPTION: assumes your underlying transcoding utility supports this encoding Big5
649	XMLTranscoder* t =
650	XMLPlatformUtils::fgTransService->makeNewTranscoderFor("Big5", failReason, 16*1024, MemoryManager);
651
652	// source string is in Unicode, wanna to transcode to Big5
653	t->transcodeTo(source_unicode, length, result_Big5, length, charsEaten, XMLTranscoder::UnRep_Throw );
654
655	// source string in Big5, wanna to transcode to Unicode
656	t->transcodeFrom(source_Big5, length, result_unicode, length, bytesEaten, (unsigned char*)charSz);
657	</PRE></FONT></TD><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></DIV>
658
659	</FONT></TD></TR></TABLE><BR><A name="faq-26"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why does setProperty not work?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
660
661	<P>The function <CODE><FONT face="courier, monospaced">SAX2XMLReader::setProperty(const XMLCh* const name, void* value)</FONT></CODE>
662	and <CODE><FONT face="courier, monospaced">DOMBuilder::setProperty(const XMLCh* const name, void* value)</FONT></CODE>
663	takes a void pointer for the property value. Application is required to initialize this void pointer
664	to a correct type. See <A href="program-sax2.html#SAX2Properties">SAX2 Programming Guide</A>
665	and <A href="program-dom.html#DOMBuilderProperties">DOM Programming Guide</A>
666	to learn exactly what type of property value that each property expects for processing.
667	Passing a void pointer that was initialized with a wrong type will lead to unexpected result.
668	</P>
669
670	</FONT></TD></TR></TABLE><BR><A name="faq-27"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why does getProperty not work?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
671
672	<P>The function <CODE><FONT face="courier, monospaced">void* SAX2XMLReader::getProperty(const XMLCh* const name)</FONT></CODE>
673	and <CODE><FONT face="courier, monospaced">void* DOMBuilder::getProperty(const XMLCh* const name)</FONT></CODE>
674	returns a void pointer for the property value. See
675	<A href="program-sax2.html#SAX2Properties">SAX2 Programming Guide</A> and
676	exactly what type of object each property returns.
677	</P>
678	<P>The parser owns the returned pointer. The memory allocated for
679	the returned pointer will be destroyed when the parser is deleted.
680	To ensure accessibility of the returned information after the parser
681	is deleted, callers need to copy and store the returned information
682	somewhere else; otherwise you may get unexpected result. Since the returned
683	pointer is a generic void pointer, see
684	<A href="program-sax2.html#SAX2Properties">SAX2 Programming Guide</A> and
685	<A href="program-dom.html#DOMBuilderProperties">DOM Programming Guide</A> to learn
686	exactly what type of property value each property returns for replication.
687	</P>
688
689	</FONT></TD></TR></TABLE><BR><A name="faq-28"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why does the parser still try to locate the DTD even validation is turned off
690	and how to ignore external DTD reference?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
691
692	<P>When DTD is referenced, the parser will try to read it, because DTDs can
693	provide a lot more information than just validation. It defines entities and
694	notations, external unparsed entities, default attributes, character
695	entities, etc... So it will always try to read it if present, even if
696	validation is turned off.
697	</P>
698
699	<P>To ignore the DTD, with Xerces-C++ 2.6.0 or up, you can call
700	<CODE><FONT face="courier, monospaced">setLoadExternalDTD(false)</FONT></CODE> (or
701	<CODE><FONT face="courier, monospaced">setFeature(XMLUni::fgXercesLoadExternalDTD, false)</FONT></CODE>
702	to disable the loading of external DTD. The parser will then ignore
703	any external DTD completely if the validationScheme is set to Val_Never.
704	</P>
705
706	<P>Note: This flag is ignored if the validationScheme is set to Val_Always or Val_Auto.
707	</P>
708
709	<P>To ignore the DTD in earlier version of Xerces-C++, the
710	only way to get around this is to install an EntityResolver
711	(see the Redirect sample for an example of how this is done), and reset the
712	DTD file to "".
713	</P>
714
715	</FONT></TD></TR></TABLE><BR><A name="faq-29"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why do I get segmentation fault when running on Redhat Linux?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
716
717	<P>There were some problems with Redhat Linux 7.x with C++ exception handling across shared
718	libraries. More details can be found
719	<A href="http://rhn.redhat.com/errata/RHBA-2002-055.html">here</A>.
720	Please try to upgrade your Redhat Linux gcc to the latest patch level and see if it helps.
721	</P>
722
723	</FONT></TD></TR></TABLE><BR><A name="faq-30"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why does the XML data generated by the DOMWriter does not match my original XML input?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
724
725	<P>If you parse an xml document using XercesDOMParser or DOMBuilder and pass such DOMNode
726	to DOMWriter for serialization, you may not get something that is exactly the same
727	as the original XML data. The parser may have done normalization, end of line conversion,
728	or has expanded the entity reference as per the XML 1.0 spec, 4.4 XML Processor Treatment of
729	Entities and References. From DOMWriter perspective, it does not know what the original
730	string was, all it sees is a processed DOMNode generated by the parser.
731	But since the DOMWriter is supposed to generate something that is parsable if sent
732	back to the parser, it will not print the DOMNode node value as is. The DOMWriter
733	may do some "touch up" to the output data for it to be parsable.</P>
734
735	<P>See <A href="program-dom.html#DOMWriterEntityRef">How does DOMWriter handle built-in entity
736	Reference in node value?</A> to understand further how DOMWriter touches up the entity reference.
737	</P>
738	</FONT></TD></TR></TABLE><BR><A name="faq-31"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why does my application crash when deleting the parser after releasing a document?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
739
740	<P>In most cases, the parser handles deleting documents when the parser gets deleted. However, if an application
741	needs to release a document, it shall adopt the document before releasing it, so that the parser
742	knows that the ownership of this particular document is transfered to the application and will not
743	try to delete it once the parser gets deleted.
744	</P>
745
746	<DIV align="left"><TABLE border="0" cellpadding="0" cellspacing="4" width="464"><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#ffffff" width="462"><FONT size="-1"><PRE>
747	XercesDOMParser *parser = new XercesDOMParser;
748	...
749	try
750	{
751	parser->parse(gXmlFile);
752	}
753	catch ()
754	{
755	...
756	}
757	DOMNode *doc = parser->getDocument();
758	...
759	parser->adoptDocument();
760	doc->release();
761	...
762	delete parser;
763	</PRE></FONT></TD><TD bgcolor="#0086b2" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" height="1" width="462"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="462"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></DIV>
764
765	<P>The alternative to release document is to call parser's resetDocumentPool(), which releases
766	all the documents parsed.
767	</P>
768
769	</FONT></TD></TR></TABLE><BR><A name="faq-32"><!--anchor--></A><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="ffffff" colspan="2" width="494"><TABLE border="0" cellpadding="0" cellspacing="0" width="494"><TR><TD bgcolor="#039acc" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#039acc" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#039acc" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#0086b2" width="492"><FONT color="#ffffff" face="arial,helvetica,sanserif" size="+1"><IMG border="0" height="2" hspace="0" src="resources/void.gif" vspace="0" width="2"><B>Why do we have two versions of some XMLString methods (one with memory manager and one without)?</B></FONT></TD><TD bgcolor="#017299" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR><TR><TD bgcolor="#0086b2" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD><TD bgcolor="#017299" height="1" width="492"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="492"></TD><TD bgcolor="#017299" height="1" width="1"><IMG border="0" height="1" hspace="0" src="resources/void.gif" vspace="0" width="1"></TD></TR></TABLE></TD></TR><TR><TD width="10"> </TD><TD width="484"><FONT color="#000000" face="arial,helvetica,sanserif">
770
771	<P>With the introduction of the configurable memory manager, we didn't want to break users by
772	changing the signature of the existing methods (for example, transcode and replicate). Also,
773	we did not want to provide a default memory
774	manager as it would introduce a side effect with users experiencing some strange core dumps.
775	The latter will occur when the scope of the string allocated is beyond that of
776	XMLPlatformUtils::Terminate (i.e. a string is allocated using the default memory manager
777	which is deleted when XMLPlatformUtils::Terminate is called, but the allocated string is
778	deleted later). We plan to deprecate the methods without a memory manager in a later release.
779	</P>
780
781	</FONT></TD></TR></TABLE><BR></TD></TR></TABLE></TD></TR></TABLE><BR><TABLE border="0" cellpadding="0" cellspacing="0" width="620"><TR><TD bgcolor="#0086b2"><IMG height="1" src="images/dot.gif" width="1"></TD></TR><TR><TD align="center"><FONT color="#0086b2" size="-1"><I>
782	Copyright © 1999-2004 The Apache Software Foundation.
783	All Rights Reserved.
784	</I></FONT></TD></TR></TABLE></BODY></HTML>

Note: See TracBrowser for help on using the repository browser.

Context Navigation

source: NonGTP/Xerces/xerces/doc/html/faq-parse.html @ 358

Download in other formats: