The QXmlInputSource class provides the input data for the
QXmlReader subclasses.
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Detailed Description
The QXmlInputSource class provides the input data for the
QXmlReader subclasses.
All subclasses of QXmlReader read the input XML document from this
class.
This class recognizes the encoding of the data by reading the
encoding declaration in the XML file if it finds one, and reading
the data using the corresponding encoding. If it does not find an
encoding declaration, then it assumes that the data is either in
UTF-8 or UTF-16, depending on whether it can find a byte-order
mark.
There are two ways to populate the input source with data: you can
construct it with a QIODevice* so that the input source reads the
data from that device. Or you can set the data explicitly with one
of the setData() functions.
Usually you either construct a QXmlInputSource that works on a
QIODevice* or you construct an empty QXmlInputSource and set the
data with setData(). There are only rare occasions where you would
want to mix both methods.
The QXmlReader subclasses use the next() function to read the
input character by character. If you want to start from the
beginning again, use reset().
The functions data() and fetchData() are useful if you want to do
something with the data other than parsing, e.g. displaying the
raw XML file. The benefit of using the QXmlInputClass in such
cases is that it tries to use the correct encoding.
See also QXmlReader, QXmlSimpleReader, and XML.
Member Function Documentation
QXmlInputSource::QXmlInputSource ()
Constructs an input source which contains no data.
See also setData().
QXmlInputSource::QXmlInputSource ( QIODevice * dev )
Constructs an input source and gets the data from device dev.
If dev is not open, it is opened in read-only mode. If dev
is 0 or it is not possible to read from the device, the input
source will contain no data.
See also setData(), fetchData(), and QIODevice.
QXmlInputSource::QXmlInputSource ( QFile & file )
This function is obsolete. It is provided to keep old source working. We strongly advise against using it in new code.
Constructs an input source and gets the data from the file file. If the
file cannot be read the input source is empty.
QXmlInputSource::QXmlInputSource ( QTextStream & stream )
This function is obsolete. It is provided to keep old source working. We strongly advise against using it in new code.
Constructs an input source and gets the data from the text stream stream.
QXmlInputSource::~QXmlInputSource () [virtual]
Destructor.
QString QXmlInputSource::data () [virtual]
Returns the data the input source contains or QString::null if the
input source does not contain any data.
See also setData(), QXmlInputSource(), and fetchData().
void QXmlInputSource::fetchData () [virtual]
This function reads more data from the device that was set during
construction. If the input source already contained data, this
function deletes that data first.
This object contains no data after a call to this function if the
object was constructed without a device to read data from or if
this function was not able to get more data from the device.
There are two occasions where a fetch is done implicitly by
another function call: during construction (so that the object
starts out with some initial data where available), and during a
call to next() (if the data had run out).
You don't normally need to use this function if you use next().
See also data(), next(), and QXmlInputSource().
QString QXmlInputSource::fromRawData ( const QByteArray & data, bool beginning = FALSE ) [virtual protected]
This function reads the XML file from data and tries to
recognize the encoding. It converts the raw data data into a
QString and returns it. It tries its best to get the correct
encoding for the XML file.
If beginning is TRUE, this function assumes that the data
starts at the beginning of a new XML document and looks for an
encoding declaration. If beginning is FALSE, it converts the
raw data using the encoding determined from prior calls.
QChar QXmlInputSource::next () [virtual]
Returns the next character of the input source. If this function
reaches the end of available data, it returns
QXmlInputSource::EndOfData. If you call next() after that, it
tries to fetch more data by calling fetchData(). If the
fetchData() call results in new data, this function returns the
first character of that data; otherwise it returns
QXmlInputSource::EndOfDocument.
See also reset(), fetchData(), QXmlSimpleReader::parse(), and QXmlSimpleReader::parseContinue().
void QXmlInputSource::reset () [virtual]
This function sets the position used by next() to the beginning of
the data returned by data(). This is useful if you want to use the
input source for more than one parse.
See also next().
Example: xml/tagreader-with-features/tagreader.cpp.
void QXmlInputSource::setData ( const QString & dat ) [virtual]
Sets the data of the input source to dat.
If the input source already contains data, this function deletes
that data first.
See also data().
void QXmlInputSource::setData ( const QByteArray & dat ) [virtual]
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
The data dat is passed through the correct text-codec, before
it is set.
This file is part of the Qt toolkit.
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