QXmlContentHandler¶

Detailed Description¶

The PySide.QtXml.QXmlContentHandler class provides an interface to report the logical content of XML data.

If the application needs to be informed of basic parsing events, it can implement this interface and activate it using QXmlReader.setContentHandler() . The reader can then report 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 sub-elements) appears, in order, between the PySide.QtXml.QXmlContentHandler.startElement() event and the corresponding PySide.QtXml.QXmlContentHandler.endElement() event.

The class PySide.QtXml.QXmlDefaultHandler provides a default implementation for this interface; subclassing from the PySide.QtXml.QXmlDefaultHandler class is very convenient if you only want to be informed of some parsing events.

The PySide.QtXml.QXmlContentHandler.startDocument() function is called at the start of the document, and PySide.QtXml.QXmlContentHandler.endDocument() is called at the end. Before parsing begins PySide.QtXml.QXmlContentHandler.setDocumentLocator() is called. For each element PySide.QtXml.QXmlContentHandler.startElement() is called, with PySide.QtXml.QXmlContentHandler.endElement() being called at the end of each element. The PySide.QtXml.QXmlContentHandler.characters() function is called with chunks of character data; PySide.QtXml.QXmlContentHandler.ignorableWhitespace() is called with chunks of whitespace and PySide.QtXml.QXmlContentHandler.processingInstruction() is called with processing instructions. If an entity is skipped PySide.QtXml.QXmlContentHandler.skippedEntity() is called. At the beginning of prefix-URI scopes PySide.QtXml.QXmlContentHandler.startPrefixMapping() is called.

See also

PySide.QtXml.QXmlDTDHandler PySide.QtXml.QXmlDeclHandler PySide.QtXml.QXmlEntityResolver PySide.QtXml.QXmlErrorHandler PySide.QtXml.QXmlLexicalHandler Introduction to SAX2

class PySide.QtXml.QXmlContentHandler¶

PySide.QtXml.QXmlContentHandler.characters(ch)¶

Parameters:	ch – unicode
Return type:	`PySide.QtCore.bool`

The reader calls this function when it has parsed a chunk of character data (either normal character data or character data inside a CDATA section; if you need to distinguish between those two types you must use QXmlLexicalHandler.startCDATA() and QXmlLexicalHandler.endCDATA() ). The character data is reported in ch .

Some readers report whitespace in element content using the PySide.QtXml.QXmlContentHandler.ignorableWhitespace() function rather than using this one.

A reader may report the character data of an element in more than one chunk; e.g. a reader might want to report “a<b” in three PySide.QtXml.QXmlContentHandler.characters() events (“a ”, “<” and ” b”).

If this function returns false the reader stops parsing and reports an error. The reader uses the function PySide.QtXml.QXmlContentHandler.errorString() to get the error message.

PySide.QtXml.QXmlContentHandler.endDocument()¶

Return type:	`PySide.QtCore.bool`

The reader calls this function after it has finished parsing. It is called just once, and is the last handler function 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 stops parsing and reports an error. The reader uses the function PySide.QtXml.QXmlContentHandler.errorString() to get the error message.

PySide.QtXml.QXmlContentHandler.endElement(namespaceURI, localName, qName)¶

Parameters:	namespaceURI – unicode localName – unicode qName – unicode
Return type:	`PySide.QtCore.bool`

The reader calls this function when it has parsed an end element tag with the qualified name qName , the local name localName and the namespace URI namespaceURI .

If this function returns false the reader stops parsing and reports an error. The reader uses the function PySide.QtXml.QXmlContentHandler.errorString() to get the error message.

See also

PySide.QtXml.QXmlContentHandler.startElement() Namespace Support via Features

PySide.QtXml.QXmlContentHandler.endPrefixMapping(prefix)¶

Parameters:	prefix – unicode
Return type:	`PySide.QtCore.bool`

The reader calls this function to signal the end of a prefix mapping for the prefix prefix .

If this function returns false the reader stops parsing and reports an error. The reader uses the function PySide.QtXml.QXmlContentHandler.errorString() to get the error message.

See also

PySide.QtXml.QXmlContentHandler.startPrefixMapping() Namespace Support via Features

PySide.QtXml.QXmlContentHandler.errorString()¶

Return type:	unicode

The reader calls this function to get an error string, e.g. if any of the handler functions returns false.

PySide.QtXml.QXmlContentHandler.ignorableWhitespace(ch)¶

Parameters:	ch – unicode
Return type:	`PySide.QtCore.bool`

Some readers may use this function to report each chunk of whitespace in element content. The whitespace is reported in ch .

If this function returns false the reader stops parsing and reports an error. The reader uses the function PySide.QtXml.QXmlContentHandler.errorString() to get the error message.

PySide.QtXml.QXmlContentHandler.processingInstruction(target, data)¶

Parameters:	target – unicode data – unicode
Return type:	`PySide.QtCore.bool`

The reader calls this function when it has parsed a processing instruction.

target is the target name of the processing instruction and data is the data in the processing instruction.

If this function returns false the reader stops parsing and reports an error. The reader uses the function PySide.QtXml.QXmlContentHandler.errorString() to get the error message.

PySide.QtXml.QXmlContentHandler.setDocumentLocator(locator)¶

Parameters:	locator – `PySide.QtXml.QXmlLocator`

The reader calls this function before it starts parsing the document. The argument locator is a pointer to a PySide.QtXml.QXmlLocator which allows the application to get the parsing position within the document.

Do not destroy the locator ; it is destroyed when the reader is destroyed. (Do not use the locator after the reader is destroyed).

PySide.QtXml.QXmlContentHandler.skippedEntity(name)¶

Parameters:	name – unicode
Return type:	`PySide.QtCore.bool`

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 report that they skipped the entity called name by calling this function.

If this function returns false the reader stops parsing and reports an error. The reader uses the function PySide.QtXml.QXmlContentHandler.errorString() to get the error message.

PySide.QtXml.QXmlContentHandler.startDocument()¶

Return type:	`PySide.QtCore.bool`

The reader calls this function when it starts parsing the document. The reader calls this function just once, after the call to PySide.QtXml.QXmlContentHandler.setDocumentLocator() , and before any other functions in this class or in the PySide.QtXml.QXmlDTDHandler class are called.

If this function returns false the reader stops parsing and reports an error. The reader uses the function PySide.QtXml.QXmlContentHandler.errorString() to get the error message.

PySide.QtXml.QXmlContentHandler.startElement(namespaceURI, localName, qName, atts)¶

Parameters:	namespaceURI – unicode localName – unicode qName – unicode atts – `PySide.QtXml.QXmlAttributes`
Return type:	`PySide.QtCore.bool`

The reader calls this function when it has parsed a start element tag.

There is a corresponding PySide.QtXml.QXmlContentHandler.endElement() call when the corresponding end element tag is read. The PySide.QtXml.QXmlContentHandler.startElement() and PySide.QtXml.QXmlContentHandler.endElement() calls are always nested correctly. Empty element tags (e.g. <x/> ) cause a PySide.QtXml.QXmlContentHandler.startElement() call to be immediately followed by an PySide.QtXml.QXmlContentHandler.endElement() call.

The attribute list provided only contains attributes with explicit values. The attribute list contains attributes used for namespace declaration (i.e. attributes starting with xmlns) only if the namespace-prefix property of the reader is true.

The argument namespaceURI is the namespace URI, or an empty string if the element has no namespace URI or if no namespace processing is done. localName is the local name (without prefix), or an empty string if no namespace processing is done, qName is the qualified name (with prefix) 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 stops parsing and reports an error. The reader uses the function PySide.QtXml.QXmlContentHandler.errorString() to get the error message.

See also

PySide.QtXml.QXmlContentHandler.endElement() Namespace Support via Features

PySide.QtXml.QXmlContentHandler.startPrefixMapping(prefix, uri)¶

Parameters:	prefix – unicode uri – unicode
Return type:	`PySide.QtCore.bool`

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 PySide.QtXml.QXmlContentHandler.startPrefixMapping() and PySide.QtXml.QXmlContentHandler.endPrefixMapping() calls are not guaranteed to be properly nested relative to each other: all PySide.QtXml.QXmlContentHandler.startPrefixMapping() events occur before the corresponding PySide.QtXml.QXmlContentHandler.startElement() event, and all PySide.QtXml.QXmlContentHandler.endPrefixMapping() events occur after the corresponding PySide.QtXml.QXmlContentHandler.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 stops parsing and reports an error. The reader uses the function PySide.QtXml.QXmlContentHandler.errorString() to get the error message.

See also

PySide.QtXml.QXmlContentHandler.endPrefixMapping() Namespace Support via Features