QXmlContentHandler(3qt)QXmlContentHandler(3qt)NAMEQXmlContentHandler - Interface to report logical content
of XML data
#include <qxml.h>
Inherited by QXmlDefaultHandler.
Public Members
virtual void setDocumentLocator ( QXmlLocator * locator )
virtual bool startDocument ()
virtual bool endDocument ()
virtual bool startPrefixMapping ( const QString & prefix,
const QString & uri )
virtual bool endPrefixMapping ( const QString & prefix )
virtual bool startElement ( const QString & namespaceURI,
const QString & localName, const QString & qName,
const QXmlAttributes & atts )
virtual bool endElement ( const QString & namespaceURI,
const QString & localName, const QString & qName )
virtual bool characters ( const QString & ch )
virtual bool ignorableWhitespace ( const QString & ch )
virtual bool processingInstruction ( const QString &
target, const QString & data )
virtual bool skippedEntity ( const QString & name )
virtual QString errorString ()
DESCRIPTION
The QXmlContentHandler class provides an interface to
report logical content of XML data.
If the application needs to be informed of basic parsing
events, it implements this interface and sets it with
QXmlReader::setContentHandler(). The reader reports basic
document-related events like the start and end of elements
and character data through this interface.
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.
The class QXmlDefaultHandler gives a default
implementation for this interface; subclassing from this
class is very convenient if you want only be informed of
some parsing events.
See also the Introduction to SAX2.
See also QXmlDTDHandler, QXmlDeclHandler,
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QXmlEntityResolver, QXmlErrorHandler and
QXmlLexicalHandler.
MEMBER FUNCTION DOCUMENTATIONbool QXmlContentHandler::characters ( const QString & ch )
[virtual]
The reader calls this function when he has parsed a chunk
of character data (either normal character data or
character data inside a CDATA section; if you have to
distinguish between those two types you have to use
QXmlLexicalHandler::startCDATA() and
QXmlLexicalHandler::endCDATA() in addition).
Some readers will report whitespace in element content
using the ignorableWhitespace() function rather than this
one (QXmlSimpleReader will do it not though).
A reader is allowed to report the character data of an
element in more than one chunk; e.g. a reader might want
to report "a < b" in three characters() events ("a ",
"<" and " b").
If this function returns FALSE the reader will stop
parsing and will report an error. The reader will use the
function errorString() to get the error message that will
be used for reporting the error.
Reimplemented in QXmlDefaultHandler.
bool QXmlContentHandler::endDocument () [virtual]
The reader calls this function after he has finished the
parsing. It is only called once. It is the last function
of all handler functions that is called. It is called
after the reader has read all input or has abandoned
parsing because of a fatal error.
If this function returns FALSE the reader will stop
parsing and will report an error. The reader will use the
function errorString() to get the error message that will
be used for reporting the error.
See also startDocument().
Reimplemented in QXmlDefaultHandler.
bool QXmlContentHandler::endElement ( const QString &
namespaceURI, const QString & localName, const QString &
qName ) [virtual]
The reader calls this function when he has parsed an end
element tag.
If this function returns FALSE the reader will stop
parsing and will report an error. The reader will use the
function errorString() to get the error message that will
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be used for reporting the error.
See also the namespace description.
See also startElement().
Reimplemented in QXmlDefaultHandler.
bool QXmlContentHandler::endPrefixMapping ( const QString &
prefix ) [virtual]
The reader calls this function to signal the end of a
prefix mapping.
If this function returns FALSE the reader will stop
parsing and will report an error. The reader will use the
function errorString() to get the error message that will
be used for reporting the error.
See also the namespace description.
See also startPrefixMapping().
Reimplemented in QXmlDefaultHandler.
QString QXmlContentHandler::errorString () [virtual]
The reader calls this function to get an error string if
any of the handler functions returns FALSE to him.
bool QXmlContentHandler::ignorableWhitespace ( const QString & ch
) [virtual]
Some readers may use this function to report each chunk of
whitespace in element content (QXmlSimpleReader does not
though).
If this function returns FALSE the reader will stop
parsing and will report an error. The reader will use the
function errorString() to get the error message that will
be used for reporting the error.
Reimplemented in QXmlDefaultHandler.
bool QXmlContentHandler::processingInstruction ( const QString &
target, const QString & data ) [virtual]
The reader calls this function when he has parsed a
processing instruction.
target is the target name of the processing instruction
and data is the data of the processing instruction.
If this function returns FALSE the reader will stop
parsing and will report an error. The reader will use the
function errorString() to get the error message that will
be used for reporting the error.
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Reimplemented in QXmlDefaultHandler.
void QXmlContentHandler::setDocumentLocator ( QXmlLocator *
locator ) [virtual]
The reader calls this function before he starts parsing
the document. The argument locator is a pointer to a
QXmlLocator which allows the application to get the actual
position of the parsing in the document.
Do not destroy the locator; it is destroyed when the
reader is destroyed (do not use the locator after the
reader got destroyed).
Reimplemented in QXmlDefaultHandler.
bool QXmlContentHandler::skippedEntity ( const QString & name )
[virtual]
Some readers may skip entities if they have not seen the
declarations (e.g. because they are in an external DTD).
If they do so they will report it by calling this
function.
If this function returns FALSE the reader will stop
parsing and will report an error. The reader will use the
function errorString() to get the error message that will
be used for reporting the error.
Reimplemented in QXmlDefaultHandler.
bool QXmlContentHandler::startDocument () [virtual]
The reader calls this function when he starts parsing the
document. The reader will call this function only once
before any other functions in this class or in the
QXmlDTDHandler class are called (except
QXmlContentHandler::setDocumentLocator()).
If this function returns FALSE the reader will stop
parsing and will report an error. The reader will use the
function errorString() to get the error message that will
be used for reporting the error.
See also endDocument().
Reimplemented in QXmlDefaultHandler.
bool QXmlContentHandler::startElement ( const QString &
namespaceURI, const QString & localName, const QString &
qName, const QXmlAttributes & atts ) [virtual]
The reader calls this function when he has parsed a start
element tag.
There will be a corresponding endElement() call when the
corresponding end element tag was read. The startElement()
and endElement() calls are always nested correctly. Empty
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element tags (e.g. <a/>) are reported by startElement()
directly followed by a call to endElement().
The attribute list provided will contain only attributes
with explicit values. The attribute list will contain
attributes used for namespace declaration (i.e. attributes
starting with xmlns) only if the namespace-prefix property
of the reader is TRUE.
The argument uri is the namespace URI, or the empty string
if the element has no namespace URI or if namespace
processing is not being performed, localName is the local
name (without prefix), or the empty string if namespace
processing is not being performed, qName is the qualified
name (with prefix), or the empty string if qualified names
are not available and atts are the attributes attached to
the element. If there are no attributes, atts is an empty
attributes object
If this function returns FALSE the reader will stop
parsing and will report an error. The reader will use the
function errorString() to get the error message that will
be used for reporting the error.
See also the namespace description.
See also endElement().
Reimplemented in QXmlDefaultHandler.
bool QXmlContentHandler::startPrefixMapping ( const QString &
prefix, const QString & uri ) [virtual]
The reader calls this function to signal the begin of a
prefix-URI namespace mapping scope. This information is
not necessary for normal namespace processing since the
reader automatically replaces prefixes for element and
attribute names.
Note that startPrefixMapping and endPrefixMapping calls
are not guaranteed to be properly nested relative to each-
other: all startPrefixMapping events will occur before the
corresponding startElement event, and all endPrefixMapping
events will occur after the corresponding endElement
event, but their order is not otherwise guaranteed.
The argument prefix is the namespace prefix being declared
and the argument uri is the namespace URI the prefix is
mapped to.
If this function returns FALSE the reader will stop
parsing and will report an error. The reader will use the
function errorString() to get the error message that will
be used for reporting the error.
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See also the namespace description.
See also endPrefixMapping().
Reimplemented in QXmlDefaultHandler.
SEE ALSO
http://doc.trolltech.com/qxmlcontenthandler.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2001 Trolltech AS,
http://www.trolltech.com. See the license file included
in the distribution for a complete license statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports
make our job much simpler. Thank you.
In case of content or formattting problems with this
manual page, please report them to qt-bugs@trolltech.com.
Please include the name of the manual page
(qxmlcontenthandler.3qt) and the Qt version (2.3.1).
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