QXmlSerializeroutputs XML without adding unnecessary whitespace. In particular, it does not add newlines and indentation. To make the XML output easier to read,
QXmlFormatteradds newlines and indentation by adding, removing, and modifying
sequence nodesthat 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
QXmlSerializerwould output this:<Code snippet "/tmp/snapshot-qt5full-v5.14.1/qt5/qtbase/patternist/notIndented.xml" not found>
QXmlFormatteroutputs this:<Code snippet "/tmp/snapshot-qt5full-v5.14.1/qt5/qtbase/patternist/indented.xml" not found>
If you just want to serialize your XML in a human-readable format, use
QXmlFormatteras it is. The default indentation level is 4 spaces, but you can set your own indentation value
The newlines and indentation added by
QXmlFormatterare 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
Note also that the indentation style used by
QXmlFormatterremains loosely defined and may change in future versions of Qt. If a specific indentation style is required then either use the base class
QXmlSerializerdirectly, or write your own subclass of
QAbstractXmlReceiver. Alternatively, you can subclass
QXmlFormatterand reimplement the callbacks there.QXmlQuery query; query.setQuery("doc('index.html')/html/body/p"); QXmlFormatter formatter(query, myOutputDevice); formatter.setIndentationDepth(2); query.evaluateTo(&formatter);
- param query
- param outputDevice
Constructs a formatter that uses the name pool and message handler in
query, and writes the result to
outputDeviceas formatted XML.
outputDeviceis passed directly to
- Return type
Returns the number of spaces
QXmlFormatterwill output for each indentation level. The default is four.
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