This is the main interface that most SAX applications * implement: if the application needs to be informed of basic parsing * events, it implements this interface and registers an instance with * the SAX parser using the setDocumentHandler method. The parser * uses the instance to report basic document-related events like * the start and end of elements and character data.
* *The order of events in this interface is very important, and * mirrors the order of information in the document itself. For * example, all of an element's content (character data, processing * instructions, and/or subelements) will appear, in order, between * the startElement event and the corresponding endElement event.
* *Application writers who do not want to implement the entire * interface while can derive a class from HandlerBase, which implements * the default functionality; parser writers can instantiate * HandlerBase to obtain a default handler. The application can find * the location of any document event using the Locator interface * supplied by the Parser through the setDocumentLocator method.
* * @see Parser#setDocumentHandler * @see Locator#Locator * @see HandlerBase#HandlerBase */ class SAX_EXPORT DocumentHandler { public: /** @name Constructors and Destructor */ //@{ /** Default constructor */ DocumentHandler() { } /** Destructor */ virtual ~DocumentHandler() { } //@} /** @name The virtual document handler interface */ //@{ /** * Receive notification of character data. * *The Parser will call this method to report each chunk of * character data. SAX parsers may return all contiguous character * data in a single chunk, or they may split it into several * chunks; however, all of the characters in any single event * must come from the same external entity, so that the Locator * provides useful information.
* *The application must not attempt to read from the array * outside of the specified range.
* *Note that some parsers will report whitespace using the * ignorableWhitespace() method rather than this one (validating * parsers must do so).
* * @param chars The characters from the XML document. * @param length The number of characters to read from the array. * @exception SAXException Any SAX exception, possibly * wrapping another exception. * @see #ignorableWhitespace * @see Locator#Locator */ virtual void characters ( const XMLCh* const chars , const unsigned int length ) = 0; /** * Receive notification of the end of a document. * *The SAX parser will invoke this method only once, and it will * be the last method invoked during the parse. The parser shall * not invoke this method until it has either abandoned parsing * (because of an unrecoverable error) or reached the end of * input.
* * @exception SAXException Any SAX exception, possibly * wrapping another exception. */ virtual void endDocument () = 0; /** * Receive notification of the end of an element. * *The SAX parser will invoke this method at the end of every * element in the XML document; there will be a corresponding * startElement() event for every endElement() event (even when the * element is empty).
* *If the element name has a namespace prefix, the prefix will * still be attached to the name.
* * @param name The element type name * @exception SAXException Any SAX exception, possibly * wrapping another exception. */ virtual void endElement(const XMLCh* const name) = 0; /** * Receive notification of ignorable whitespace in element content. * *Validating Parsers must use this method to report each chunk * of ignorable whitespace (see the W3C XML 1.0 recommendation, * section 2.10): non-validating parsers may also use this method * if they are capable of parsing and using content models.
* *SAX parsers may return all contiguous whitespace in a single * chunk, or they may split it into several chunks; however, all of * the characters in any single event must come from the same * external entity, so that the Locator provides useful * information.
* *The application must not attempt to read from the array * outside of the specified range.
* * @param chars The characters from the XML document. * @param length The number of characters to read from the array. * @exception SAXException Any SAX exception, possibly * wrapping another exception. * @see #characters */ virtual void ignorableWhitespace ( const XMLCh* const chars , const unsigned int length ) = 0; /** * Receive notification of a processing instruction. * *The Parser will invoke this method once for each processing * instruction found: note that processing instructions may occur * before or after the main document element.
* *A SAX parser should never report an XML declaration (XML 1.0, * section 2.8) or a text declaration (XML 1.0, section 4.3.1) * using this method.
* * @param target The processing instruction target. * @param data The processing instruction data, or null if * none was supplied. * @exception SAXException Any SAX exception, possibly * wrapping another exception. */ virtual void processingInstruction ( const XMLCh* const target , const XMLCh* const data ) = 0; /** * Reset the Docuemnt object on its reuse * *This method helps in reseting the document implementational * defaults each time the document is begun.
* */ virtual void resetDocument() = 0; /** * Receive an object for locating the origin of SAX document events. * * SAX parsers are strongly encouraged (though not absolutely * required) to supply a locator: if it does so, it must supply * the locator to the application by invoking this method before * invoking any of the other methods in the DocumentHandler * interface. * * The locator allows the application to determine the end * position of any document-related event, even if the parser is * not reporting an error. Typically, the application will * use this information for reporting its own errors (such as * character content that does not match an application's * business rules). The information returned by the locator * is probably not sufficient for use with a search engine. * * Note that the locator will return correct information only * during the invocation of the events in this interface. The * application should not attempt to use it at any other time. * * @param locator An object that can return the location of * any SAX document event. The object is only * 'on loan' to the client code and they are not * to attempt to delete or modify it in any way! * * @see Locator#Locator */ virtual void setDocumentLocator(const Locator* const locator) = 0; /** * Receive notification of the beginning of a document. * *The SAX parser will invoke this method only once, before any * other methods in this interface or in DTDHandler (except for * setDocumentLocator).
* * @exception SAXException Any SAX exception, possibly * wrapping another exception. */ virtual void startDocument() = 0; /** * Receive notification of the beginning of an element. * *The Parser will invoke this method at the beginning of every * element in the XML document; there will be a corresponding * endElement() event for every startElement() event (even when the * element is empty). All of the element's content will be * reported, in order, before the corresponding endElement() * event.
* *If the element name has a namespace prefix, the prefix will * still be attached. Note that the attribute list provided will * contain only attributes with explicit values (specified or * defaulted): #IMPLIED attributes will be omitted.
* * @param name The element type name. * @param attrs The attributes attached to the element, if any. * @exception SAXException Any SAX exception, possibly * wrapping another exception. * @see #endElement * @see AttributeList#AttributeList */ virtual void startElement ( const XMLCh* const name , AttributeList& attrs ) = 0; //@} private : /* Unimplemented Constructors and operators */ /* Copy constructor */ DocumentHandler(const DocumentHandler&); /** Assignment operator */ DocumentHandler& operator=(const DocumentHandler&); }; XERCES_CPP_NAMESPACE_END #endif