QXmlReader Class

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# QXmlReader Class Reference
[XML module]

The QXmlReader class provides an interface for XML readers (i.e. parsers). More...

`#include <qxml.h>`

Inherited by QXmlSimpleReader.

List of all member functions.

## Public Members

- virtual bool feature ( const QString & name, bool * ok = 0 ) const
- virtual void setFeature ( const QString & name, bool value )
- virtual bool hasFeature ( const QString & name ) const
- virtual void * property ( const QString & name, bool * ok = 0 ) const
- virtual void setProperty ( const QString & name, void * value )
- virtual bool hasProperty ( const QString & name ) const
- virtual void setEntityResolver ( QXmlEntityResolver * handler )
- virtual QXmlEntityResolver * entityResolver () const
- virtual void setDTDHandler ( QXmlDTDHandler * handler )
- virtual QXmlDTDHandler * DTDHandler () const
- virtual void setContentHandler ( QXmlContentHandler * handler )
- virtual QXmlContentHandler * contentHandler () const
- virtual void setErrorHandler ( QXmlErrorHandler * handler )
- virtual QXmlErrorHandler * errorHandler () const
- virtual void setLexicalHandler ( QXmlLexicalHandler * handler )
- virtual QXmlLexicalHandler * lexicalHandler () const
- virtual void setDeclHandler ( QXmlDeclHandler * handler )
- virtual QXmlDeclHandler * declHandler () const
- virtual bool parse ( const QXmlInputSource & input ) (obsolete)
- virtual bool parse ( const QXmlInputSource * input )

## Detailed Description

The QXmlReader class provides an interface for XML readers (i.e. parsers).

This abstract class provides an interface for all XML readers in Qt. At the moment there is only one implementation of a reader included in the XML module of Qt (QXmlSimpleReader). In future releases there might be more readers with different properties available (e.g. a validating parser).

The design of the XML classes follows the SAX2 java interface. It was adapted to fit the Qt naming conventions; so it should be very easy for anybody who has worked with SAX2 to get started with the Qt XML classes.

All readers use the class QXmlInputSource to read the input document. Since you are normally interested in particular content in the XML document, the reader reports the content through special handler classes (QXmlDTDHandler, QXmlDeclHandler, QXmlContentHandler, QXmlEntityResolver, QXmlErrorHandler and QXmlLexicalHandler), which you must subclass, if you want to process the contents..

Since the handler classes describe only interfaces you must implement all functions; there is a class (QXmlDefaultHandler) to make this easier; it implements a default behaviour (do nothing) for all functions.

Features and properties of the reader can be set with setFeature() and setProperty respectively. You can set the reader to use your own subclasses with setEntityResolver(), setDTDHandler(), setContentHandler(), setErrorHandler(), setLexicalHandler() and setDeclHandler(). The parse itself is started with a call to parse().

For getting started see also the tiny SAX2 parser walkthrough.

See also QXmlSimpleReader and XML.

## Member Function Documentation

### QXmlDTDHandler * QXmlReader::DTDHandler () const`[virtual]`

Returns the DTD handler or 0 if none was set.

See also setDTDHandler().

### QXmlContentHandler * QXmlReader::contentHandler () const`[virtual]`

Returns the content handler or 0 if none was set.

See also setContentHandler().

### QXmlDeclHandler * QXmlReader::declHandler () const`[virtual]`

Returns the declaration handler or 0 if none was set.

See also setDeclHandler().

### QXmlEntityResolver * QXmlReader::entityResolver () const`[virtual]`

Returns the entity resolver or 0 if none was set.

See also setEntityResolver().

### QXmlErrorHandler * QXmlReader::errorHandler () const`[virtual]`

Returns the error handler or 0 if none was set.

See also setErrorHandler().

### bool QXmlReader::feature ( const QString & name, bool * ok = 0 ) const`[virtual]`

If the reader has the feature called name, the feature's value is returned. If no such feature exists the return value is undefined.

If ok is not 0, then *ok is set to TRUE if the reader has the feature called name; otherwise *ok is set to FALSE.

See also setFeature() and hasFeature().

### bool QXmlReader::hasFeature ( const QString & name ) const`[virtual]`

Returns `TRUE` if the reader has the feature name; otherwise returns FALSE.

See also feature() and setFeature().

### bool QXmlReader::hasProperty ( const QString & name ) const`[virtual]`

Returns TRUE if the reader has the property name; otherwise returns FALSE.

See also property() and setProperty().

### QXmlLexicalHandler * QXmlReader::lexicalHandler () const`[virtual]`

Returns the lexical handler or 0 if none was set.

See also setLexicalHandler().

### bool QXmlReader::parse ( const QXmlInputSource * input )`[virtual]`

Reads an XML document from input and parses it. Returns TRUE if the parsing was successful; otherwise returns FALSE.

Examples: xml/tagreader-with-features/tagreader.cpp and xml/tagreader/tagreader.cpp.

### bool QXmlReader::parse ( const QXmlInputSource & input )`[virtual]`

This function is obsolete. It is provided to keep old source working. We strongly advise against using it in new code.

### void * QXmlReader::property ( const QString & name, bool * ok = 0 ) const`[virtual]`

If the reader has the property name, this function returns the value of the property and sets *ok to TRUE; otherwise *ok is set to FALSE.

See also setProperty() and hasProperty().

### void QXmlReader::setContentHandler ( QXmlContentHandler * handler )`[virtual]`

Sets the content handler to handler.

See also contentHandler().

Examples: xml/tagreader-with-features/tagreader.cpp and xml/tagreader/tagreader.cpp.

### void QXmlReader::setDTDHandler ( QXmlDTDHandler * handler )`[virtual]`

Sets the DTD handler to handler.

See also DTDHandler().

### void QXmlReader::setDeclHandler ( QXmlDeclHandler * handler )`[virtual]`

Sets the declaration handler to handler.

See also declHandler().

### void QXmlReader::setEntityResolver ( QXmlEntityResolver * handler )`[virtual]`

Sets the entity resolver to handler.

See also entityResolver().

### void QXmlReader::setErrorHandler ( QXmlErrorHandler * handler )`[virtual]`

Sets the error handler to handler. Clears the error handler if handler is 0.

See also errorHandler().

### void QXmlReader::setFeature ( const QString & name, bool value )`[virtual]`

Sets the feature called name to the given value. If the reader doesn't have the feature nothing happens.

See also feature() and hasFeature().

Example: xml/tagreader-with-features/tagreader.cpp.

### void QXmlReader::setLexicalHandler ( QXmlLexicalHandler * handler )`[virtual]`

Sets the lexical handler to handler.

See also lexicalHandler().

### void QXmlReader::setProperty ( const QString & name, void * value )`[virtual]`

Sets the property name to value. If the reader doesn't have the property nothing happens.

See also property() and hasProperty().

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