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QXmlStreamWriter Class Reference
[com.trolltech.qt.xml module]

The QXmlStreamWriter class provides an XML writer with a simple streaming API. More...


Detailed Description

The QXmlStreamWriter class provides an XML writer with a simple streaming API.

QXmlStreamWriter is the pendent to QXmlStreamReader for writing XML. Like its related class, it operates on a QIODevice specified with setDevice. The API is simple and straight forward: For every XML token or event you want to write, the writer provides a specialized function.

You start a document with writeStartDocument and end it with writeEndDocument. This will implicitly close all remaining open tags.

Element tags are opened with writeStartElement followed by writeAttribute or writeAttributes, element content, and then writeEndElement. A shorter form writeEmptyElement can be used to write empty elements.

Element content consists of either characters, entity references or nested elements. It is written with writeCharacters, which also takes care of escaping all forbidden characters and character sequences, writeEntityReference, or subsequent calls to writeStartElement. A convenience method writeTextElement can be used for writing terminal elements that contain nothing but text.

QXmlStreamWriter takes care of prefixing namespaces, all you have to do is specify the namespaceUri when writing elements or attributes. If you must conform to certain prefixes, you can force the writer to use them by declaring the namespaces manually with either writeNamespace or writeDefaultNamespace. Alternatively, you can bypass the stream writer's namespace support and use overloaded methods that take a qualified name instead. The namespace http://www.w3.org/XML/1998/namespace is implicit and mapped to the prefix xml.

The stream writer can automatically format the generated XML data by adding line-breaks and indentation to empty sections between elements, making the XML data more readable for humans and easier to work with for most source code management systems. The feature can be turned on with the autoFormatting property.

Other functions are writeCDATA, writeComment, writeProcessingInstruction, and writeDTD. Chaining of XML streams is supported with writeCurrentToken.

By default, QXmlStreamWriter encodes XML in UTF-8. Different encodings can be enforced using setCodec.

The QXmlStream Bookmarks Example illustrates how to use a subclassed stream writer to write an XML bookmark file (XBEL) that was previously read in by a QXmlStreamReader.


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Qt Jambi 4.3.4_01