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

Inheritance diagram for QXmlFormatter:

Public Methods
	QXmlFormatter (const QXmlQuery &query, QIODevice *outputDevice)

void	atomicValue (const QVariant &value) override

void	attribute (const QXmlName &name, QStringView value) override

void	characters (QStringView value) override

void	comment (const QString &value) override

void	endDocument () override

void	endElement () override

void	endOfSequence () override

int	indentationDepth () const

void	processingInstruction (const QXmlName &name, const QString &value) override

void	setIndentationDepth (int depth)

void	startDocument () override

void	startElement (const QXmlName &name) override

void	startOfSequence () override

Public Methods inherited from QXmlSerializer
	QXmlSerializer (const QXmlQuery &query, QIODevice *outputDevice)

void	atomicValue (const QVariant &value) override

void	attribute (const QXmlName &name, QStringView value) override

void	characters (QStringView value) override

const QTextCodec *	codec () const

void	comment (const QString &value) override

void	endDocument () override

void	endElement () override

void	endOfSequence () override

void	namespaceBinding (const QXmlName &nb) override

QIODevice *	outputDevice () const

void	processingInstruction (const QXmlName &name, const QString &value) override

void	setCodec (const QTextCodec *codec)

void	startDocument () override

void	startElement (const QXmlName &name) override

void	startOfSequence () override

Public Methods inherited from QAbstractXmlReceiver
	QAbstractXmlReceiver ()

virtual	~QAbstractXmlReceiver ()

Detailed Description

The QXmlFormatter class is an implementation of QXmlSerializer for transforming XQuery output into formatted XML. This class 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 will output the following.

In comparison QXmlFormatter outputs the following.

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

If you just want to serialize your XML in a human-readable format use QXmlFormatter The default indentation level is 4 spaces. This value can be set to any indentation value using 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.

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

The indentation style used by QXmlFormatter remains loosely defined. 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);

See also: QXmlSerializer

Constructor & Destructor Documentation

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. The given outputDevice is passed directly to QXmlSerializer's constructor.