QXmlFormatter Class

The QXmlFormatter class is an implementation of QXmlSerializer for transforming XQuery output into formatted XML. 更多...

头：	#include <QXmlFormatter>
qmake:	QT += xmlpatterns
Since:	Qt 4.4
继承：	QXmlSerializer

该类在 Qt 4.4 引入。

• 所有成员列表，包括继承成员

注意： 此类的所有函数 可重入 .

公共函数

	QXmlFormatter (const QXmlQuery & query , QIODevice * outputDevice )
int	indentationDepth () const
void	setIndentationDepth (int depth )

重实现公共函数

virtual void	atomicValue (const QVariant & value ) override
virtual void	属性 (const QXmlName & name , const QStringRef & value ) override
virtual void	characters (const QStringRef & value ) override
virtual void	comment (const QString & value ) override
virtual void	endDocument () override
virtual void	endElement () override
virtual void	endOfSequence () override
virtual void	processingInstruction (const QXmlName & name , const QString & value ) override
virtual void	startDocument () override
virtual void	startElement (const QXmlName & name ) override
virtual void	startOfSequence () override

详细描述

QXmlFormatter is a subclass of QXmlSerializer that formats the XML output to make it easier for humans to read.

QXmlSerializer outputs XML without adding unnecessary whitespace. In particular, it does not add newlines and indentation. To make the XML output easier to read, QXmlFormatter adds newlines and indentation by adding, removing, and modifying sequence nodes that only consist of whitespace. It also modifies whitespace in other places where it is not significant; e.g., between attributes and in the document prologue.

For example, where the base class QXmlSerializer would output this:

<a><b/><c/><p>Some Text</p></a>
					

QXmlFormatter outputs this:

<a>
   <b/>
   <c/>
   <p>Some Text</p>
</a>
					

If you just want to serialize your XML in a human-readable format, use QXmlFormatter as it is. The default indentation level is 4 spaces, but you can set your own indentation value setIndentationDepth ().

The newlines and indentation added by QXmlFormatter are suitable for common formats, such as XHTML, SVG, or Docbook, where whitespace is not significant. However, if your XML will be used as input where whitespace is significant, then you must write your own subclass of QXmlSerializer or QAbstractXmlReceiver .

Note that using QXmlFormatter instead of QXmlSerializer will increase computational overhead and document storage size due to the insertion of whitespace.

Note also that the indentation style used by QXmlFormatter remains loosely defined and may change in future versions of Qt. If a specific indentation style is required then either use the base class QXmlSerializer directly, or write your own subclass of QXmlSerializer or QAbstractXmlReceiver . Alternatively, you can subclass QXmlFormatter and reimplement the callbacks there.

QXmlQuery query;
query.setQuery("doc('index.html')/html/body/p[1]");
QXmlFormatter formatter(query, myOutputDevice);
formatter.setIndentationDepth(2);
query.evaluateTo(&formatter);
					

成员函数文档编制

QXmlFormatter:: QXmlFormatter (const QXmlQuery & query , QIODevice * outputDevice )

Constructs a formatter that uses the name pool and message handler in query , and writes the result to outputDevice as formatted XML.

outputDevice is passed directly to QXmlSerializer 的构造函数。

另请参阅 QXmlSerializer .

[override virtual] void QXmlFormatter:: atomicValue (const QVariant & value )

重实现： QXmlSerializer::atomicValue (const QVariant &value).

[override virtual] void QXmlFormatter:: 属性 (const QXmlName & name , const QStringRef & value )

重实现： QXmlSerializer::attribute (const QXmlName &name, const QStringRef &value).

[override virtual] void QXmlFormatter:: characters (const QStringRef & value )

重实现： QXmlSerializer::characters (const QStringRef &value).

[override virtual] void QXmlFormatter:: comment (const QString & value )

重实现： QXmlSerializer::comment (const QString &value).

[override virtual] void QXmlFormatter:: endDocument ()

重实现： QXmlSerializer::endDocument ().

[override virtual] void QXmlFormatter:: endElement ()

重实现： QXmlSerializer::endElement ().

[override virtual] void QXmlFormatter:: endOfSequence ()

重实现： QXmlSerializer::endOfSequence ().

int QXmlFormatter:: indentationDepth () const

Returns the number of spaces QXmlFormatter will output for each indentation level. The default is four.

另请参阅 setIndentationDepth ().

[override virtual] void QXmlFormatter:: processingInstruction (const QXmlName & name , const QString & value )

重实现： QXmlSerializer::processingInstruction (const QXmlName &name, const QString &value).

void QXmlFormatter:: setIndentationDepth ( int depth )

设置 depth to be the number of spaces QXmlFormatter will output for level of indentation. The default is four.

另请参阅 indentationDepth ().

[override virtual] void QXmlFormatter:: startDocument ()

重实现： QXmlSerializer::startDocument ().

[override virtual] void QXmlFormatter:: startElement (const QXmlName & name )

重实现： QXmlSerializer::startElement (const QXmlName &name).

[override virtual] void QXmlFormatter:: startOfSequence ()

重实现： QXmlSerializer::startOfSequence ().

内容

• 公共函数

• 重实现公共函数

• 详细描述