This class reads data from a WFS server or alternatively from a GML file. More...

#include <qgswfsdata.h>

Collaboration diagram for QgsWFSData:

Signals
void	dataProgressAndSteps (int progress, int totalSteps)
void	dataReadProgress (int progress)
void	totalStepsUpdate (int totalSteps)
Public Member Functions
	QgsWFSData (const QString &uri, QgsRectangle extent, QMap< QgsFeatureId, QgsFeature > &features, QMap< QgsFeatureId, QString > &idMap, const QString &geometryAttribute, const QMap< QString, QPair< int, QgsField > > &thematicAttributes, QGis::WkbType *wkbType)
	Constructor.
	~QgsWFSData ()
int	getWFSData ()
	Does the Http GET request to the wfs server.
Private Types
enum	parseMode { boundingBox, featureMember, attribute, geometry, coordinate, point, line, polygon, multiPoint, multiLine, multiPolygon }
Private Slots
void	handleProgressEvent (qint64 progress, qint64 totalSteps)
	Takes progress value and total steps and emit signals 'dataReadProgress' and 'totalStepUpdate'.
void	setFinished ()
Private Member Functions
	QgsWFSData ()
void	calculateExtentFromFeatures () const
	This function evaluates the layer bounding box from the features and sets it to mExtent.
void	characters (const XML_Char *chars, int len)
int	createBBoxFromCoordinateString (QgsRectangle *bb, const QString &coordString) const
	Creates a rectangle from a coordinate string.
int	createMultiLineFromFragments ()
	Creates a multiline from the information in mCurrentWKBFragments and mCurrentWKBFragmentSizes.
int	createMultiPointFromFragments ()
int	createMultiPolygonFromFragments ()
int	createPolygonFromFragments ()
void	endElement (const XML_Char *el)
QWidget *	findMainWindow () const
	Returns pointer to main window or 0 if it does not exist.
int	getLineWKB (unsigned char *wkb, int size, const std::list< QgsPoint > &lineCoordinates) const
int	getPointWKB (unsigned char *wkb, int size, const QgsPoint &) const
int	getRingWKB (unsigned char *wkb, int size, const std::list< QgsPoint > &ringCoordinates) const
int	pointsFromCoordinateString (std::list< QgsPoint > &points, const QString &coordString) const
	Creates a set of points from a coordinate string.
QString	readAttribute (const QString &attributeName, const XML_Char **attr) const
	Reads attribute as string.
int	readEpsgFromAttribute (int &epsgNr, const XML_Char **attr) const
	Reads attribute srsName="EpsgCrsId:...".
void	startElement (const XML_Char el, const XML_Char *attr)
	XML handler methods.
int	totalWKBFragmentSize () const
	Adds all the integers contained in mCurrentWKBFragmentSizes.
Static Private Member Functions
static void	chars (void data, const XML_Char chars, int len)
static void	end (void data, const XML_Char el)
static void	start (void data, const XML_Char el, const XML_Char **attr)
Private Attributes
QString	mAttributeName
QString	mCoordinateSeparator
	Coordinate separator for coordinate strings.
QVector< QVariant >	mCurrentAttributes
QgsFeature *	mCurrentFeature
QString	mCurrentFeatureId
unsigned char *	mCurrentWKB
	The total WKB for a feature.
std::list< std::list< unsigned char * > >	mCurrentWKBFragments
	WKB intermediate storage during parsing.
std::list< std::list< int > >	mCurrentWKBFragmentSizes
	Similar to mCurrentWKB, but only the size.
int	mCurrentWKBSize
	The total WKB size for a feature.
QgsApplication::endian_t	mEndian
QgsRectangle *	mExtent
	Bounding box of the layer.
int	mFeatureCount
QMap< QgsFeatureId, QgsFeature * > &	mFeatures
	The features of the layer.
bool	mFinished
	True if the request is finished.
QString	mGeometryAttribute
	Name of geometry attribute.
QMap< QgsFeatureId, QString > &	mIdMap
	Stores the relation between provider ids and WFS server ids.
std::stack< parseMode >	mParseModeStack
	Keep track about the most important nested elements.
QString	mStringCash
	This contains the character data if an important element has been encountered.
const QMap< QString, QPair < int, QgsField > > &	mThematicAttributes
QString	mTupleSeparator
	Tuple separator for coordinate strings.
QString	mTypeName
QString	mUri
QGis::WkbType *	mWkbType

Detailed Description

This class reads data from a WFS server or alternatively from a GML file.

It uses the expat XML parser and an event based model to keep performance high. The parsing starts when the first data arrives, it does not wait until the request is finished

Definition at line 34 of file qgswfsdata.h.

Member Enumeration Documentation

enum QgsWFSData::parseMode [private]

Enumerator:

boundingBox
featureMember
attribute
geometry
coordinate
point
line
polygon
multiPoint
multiLine
multiPolygon

Definition at line 74 of file qgswfsdata.h.

Constructor & Destructor Documentation

QgsWFSData::QgsWFSData	(	const QString &	uri,
		QgsRectangle *	extent,
		QMap< QgsFeatureId, QgsFeature * > &	features,
		QMap< QgsFeatureId, QString > &	idMap,
		const QString &	geometryAttribute,
		const QMap< QString, QPair< int, QgsField > > &	thematicAttributes,
		QGis::WkbType *	wkbType
	)

Constructor.

Parameters:

uri	request uri
extent	the extent of the WFS layer
features	the features of the layer
idMap
geometryAttribute
thematicAttributes
wkbType

Definition at line 33 of file qgswfsdata.cpp.

References QgsApplication::endian(), mEndian, mTypeName, and QgsDebugMsg.

QgsWFSData::~QgsWFSData ( )

Definition at line 73 of file qgswfsdata.cpp.

QgsWFSData::QgsWFSData ( ) [private]

Member Function Documentation

void QgsWFSData::calculateExtentFromFeatures ( ) const [private]

This function evaluates the layer bounding box from the features and sets it to mExtent.

Less efficient compared to reading the bbox from the provider, so it is only done if the wfs server does not provider extent information.

Definition at line 833 of file qgswfsdata.cpp.

References QgsGeometry::boundingBox(), QgsFeature::geometry(), mFeatures, and QgsRectangle::unionRect().

Referenced by getWFSData().

void QgsWFSData::characters	(	const XML_Char *	chars,
		int	len
	)		`[private]`

Definition at line 455 of file qgswfsdata.cpp.

References attribute, coordinate, mParseModeStack, and mStringCash.

static void QgsWFSData::chars	(	void *	data,
		const XML_Char *	chars,
		int	len
	)		`[inline, static, private]`

Definition at line 103 of file qgswfsdata.h.

Referenced by getWFSData().

int QgsWFSData::createBBoxFromCoordinateString	(	QgsRectangle *	bb,
		const QString &	coordString
	)		const `[private]`

Creates a rectangle from a coordinate string.

Returns:: 0 in case of success

Definition at line 516 of file qgswfsdata.cpp.

References pointsFromCoordinateString(), and QgsRectangle::set().

Referenced by endElement().

int QgsWFSData::createMultiLineFromFragments ( ) [private]

Creates a multiline from the information in mCurrentWKBFragments and mCurrentWKBFragmentSizes.

Assign the result. The multiline is in mCurrentWKB and mCurrentWKBSize. The function deletes the memory in mCurrentWKBFragments. Returns 0 in case of success.

Definition at line 646 of file qgswfsdata.cpp.

References mCurrentWKB, mCurrentWKBFragments, mCurrentWKBFragmentSizes, mCurrentWKBSize, mEndian, mWkbType, totalWKBFragmentSize(), and QGis::WKBMultiLineString.

Referenced by endElement().

int QgsWFSData::createMultiPointFromFragments ( ) [private]

Definition at line 680 of file qgswfsdata.cpp.

References mCurrentWKB, mCurrentWKBFragments, mCurrentWKBFragmentSizes, mCurrentWKBSize, mEndian, mWkbType, totalWKBFragmentSize(), and QGis::WKBMultiPoint.

Referenced by endElement().

int QgsWFSData::createMultiPolygonFromFragments ( ) [private]

Definition at line 747 of file qgswfsdata.cpp.

References mCurrentWKB, mCurrentWKBFragments, mCurrentWKBFragmentSizes, mCurrentWKBSize, mEndian, mWkbType, totalWKBFragmentSize(), QGis::WKBMultiPolygon, and QGis::WKBPolygon.

Referenced by endElement().

int QgsWFSData::createPolygonFromFragments ( ) [private]

Definition at line 715 of file qgswfsdata.cpp.

References mCurrentWKB, mCurrentWKBFragments, mCurrentWKBFragmentSizes, mCurrentWKBSize, mEndian, mWkbType, totalWKBFragmentSize(), and QGis::WKBPolygon.

Referenced by endElement().

void QgsWFSData::dataProgressAndSteps	(	int	progress,
		int	totalSteps
	)		`[signal]`

Referenced by handleProgressEvent().

void QgsWFSData::dataReadProgress ( int progress ) [signal]

Referenced by getWFSData(), and handleProgressEvent().

static void QgsWFSData::end	(	void *	data,
		const XML_Char *	el
	)		`[inline, static, private]`

Definition at line 99 of file qgswfsdata.h.

Referenced by getWFSData().

void QgsWFSData::endElement ( const XML_Char * el ) [private]

Definition at line 244 of file qgswfsdata.cpp.

References boundingBox, createBBoxFromCoordinateString(), createMultiLineFromFragments(), createMultiPointFromFragments(), createMultiPolygonFromFragments(), createPolygonFromFragments(), getLineWKB(), getPointWKB(), getRingWKB(), GML_NAMESPACE, QgsFeature::id(), mAttributeName, mCurrentFeature, mCurrentFeatureId, mCurrentWKB, mCurrentWKBFragments, mCurrentWKBFragmentSizes, mCurrentWKBSize, mExtent, mFeatureCount, mFeatures, mGeometryAttribute, mIdMap, mParseModeStack, mStringCash, mThematicAttributes, multiLine, multiPoint, multiPolygon, mWkbType, NS_SEPARATOR, pointsFromCoordinateString(), QgsDebugMsg, QgsFeature::setAttribute(), QgsFeature::setGeometryAndOwnership(), QGis::WKBLineString, QGis::WKBMultiLineString, QGis::WKBMultiPoint, QGis::WKBMultiPolygon, QGis::WKBPoint, and QGis::WKBPolygon.

QWidget * QgsWFSData::findMainWindow ( ) const [private]

Returns pointer to main window or 0 if it does not exist.

Definition at line 816 of file qgswfsdata.cpp.

Referenced by getWFSData().

int QgsWFSData::getLineWKB	(	unsigned char **	wkb,
		int *	size,
		const std::list< QgsPoint > &	lineCoordinates
	)		const `[private]`

Definition at line 591 of file qgswfsdata.cpp.

References mEndian, and QGis::WKBLineString.

Referenced by endElement().

int QgsWFSData::getPointWKB	(	unsigned char **	wkb,
		int *	size,
		const QgsPoint &	point
	)		const `[private]`

Definition at line 571 of file qgswfsdata.cpp.

References mEndian, QGis::WKBPoint, QgsPoint::x(), and QgsPoint::y().

Referenced by endElement().

int QgsWFSData::getRingWKB	(	unsigned char **	wkb,
		int *	size,
		const std::list< QgsPoint > &	ringCoordinates
	)		const `[private]`

Definition at line 622 of file qgswfsdata.cpp.

Referenced by endElement().

int QgsWFSData::getWFSData ( )

Does the Http GET request to the wfs server.

Returns:: 0 in case of success

Definition at line 78 of file qgswfsdata.cpp.

References calculateExtentFromFeatures(), chars(), dataReadProgress(), end(), findMainWindow(), handleProgressEvent(), QgsNetworkAccessManager::instance(), QgsRectangle::isEmpty(), mExtent, mFinished, mTypeName, mUri, mWkbType, NS_SEPARATOR, QgsRectangle::set(), setFinished(), start(), totalStepsUpdate(), tr, and QGis::WKBNoGeometry.

void QgsWFSData::handleProgressEvent	(	qint64	progress,
		qint64	totalSteps
	)		`[private, slot]`

Takes progress value and total steps and emit signals 'dataReadProgress' and 'totalStepUpdate'.

Definition at line 148 of file qgswfsdata.cpp.

References dataProgressAndSteps(), dataReadProgress(), and totalStepsUpdate().

Referenced by getWFSData().

int QgsWFSData::pointsFromCoordinateString	(	std::list< QgsPoint > &	points,
		const QString &	coordString
	)		const `[private]`

Creates a set of points from a coordinate string.

Parameters:

points	list that will contain the created points
coordString	the text containing the coordinates

Returns:: 0 in case of success

Definition at line 540 of file qgswfsdata.cpp.

References mCoordinateSeparator, and mTupleSeparator.

Referenced by createBBoxFromCoordinateString(), and endElement().

QString QgsWFSData::readAttribute	(	const QString &	attributeName,
		const XML_Char **	attr
	)		const `[private]`

Reads attribute as string.

Parameters:

attributeName
attr

Returns:: attribute value or an empty string if no such attribute

Definition at line 502 of file qgswfsdata.cpp.

Referenced by startElement().

int QgsWFSData::readEpsgFromAttribute	(	int &	epsgNr,
		const XML_Char **	attr
	)		const `[private]`

Reads attribute srsName="EpsgCrsId:...".

Parameters:

epsgNr	result
attr	attribute strings

Returns:: 0 in case of success

Definition at line 471 of file qgswfsdata.cpp.

Referenced by startElement().

void QgsWFSData::setFinished ( ) [private, slot]

Definition at line 143 of file qgswfsdata.cpp.

References mFinished.

Referenced by getWFSData().

static void QgsWFSData::start	(	void *	data,
		const XML_Char *	el,
		const XML_Char **	attr
	)		`[inline, static, private]`

Definition at line 95 of file qgswfsdata.h.

Referenced by getWFSData().

void QgsWFSData::startElement	(	const XML_Char *	el,
		const XML_Char **	attr
	)		`[private]`

XML handler methods.

Definition at line 159 of file qgswfsdata.cpp.

References attribute, boundingBox, coordinate, featureMember, geometry, GML_NAMESPACE, mAttributeName, mCoordinateSeparator, mCurrentFeature, mCurrentFeatureId, mCurrentWKBFragments, mCurrentWKBFragmentSizes, mFeatureCount, mGeometryAttribute, mParseModeStack, mStringCash, mThematicAttributes, mTupleSeparator, mTypeName, multiLine, multiPoint, multiPolygon, NS_SEPARATOR, QgsDebugMsg, readAttribute(), readEpsgFromAttribute(), and QgsFeature::setAttributes().

void QgsWFSData::totalStepsUpdate ( int totalSteps ) [signal]

Referenced by getWFSData(), and handleProgressEvent().

int QgsWFSData::totalWKBFragmentSize ( ) const [private]

Adds all the integers contained in mCurrentWKBFragmentSizes.

Definition at line 803 of file qgswfsdata.cpp.

References mCurrentWKBFragmentSizes.

Referenced by createMultiLineFromFragments(), createMultiPointFromFragments(), createMultiPolygonFromFragments(), and createPolygonFromFragments().

Member Data Documentation

QString QgsWFSData::mAttributeName [private]

Definition at line 176 of file qgswfsdata.h.

Referenced by endElement(), and startElement().

QString QgsWFSData::mCoordinateSeparator [private]

Coordinate separator for coordinate strings.

Usually ","

Definition at line 180 of file qgswfsdata.h.

Referenced by pointsFromCoordinateString(), and startElement().

QVector<QVariant> QgsWFSData::mCurrentAttributes [private]

Definition at line 165 of file qgswfsdata.h.

QgsFeature* QgsWFSData::mCurrentFeature [private]

Definition at line 164 of file qgswfsdata.h.

Referenced by endElement(), and startElement().

QString QgsWFSData::mCurrentFeatureId [private]

Definition at line 166 of file qgswfsdata.h.

Referenced by endElement(), and startElement().

unsigned char* QgsWFSData::mCurrentWKB [private]

The total WKB for a feature.

Definition at line 169 of file qgswfsdata.h.

Referenced by createMultiLineFromFragments(), createMultiPointFromFragments(), createMultiPolygonFromFragments(), createPolygonFromFragments(), and endElement().

std::list< std::list<unsigned char*> > QgsWFSData::mCurrentWKBFragments [private]

WKB intermediate storage during parsing.

For points and lines, no intermediate WKB is stored at all. For multipoins and multilines and polygons, only one nested list is used. For multipolygons, both nested lists are used

Definition at line 173 of file qgswfsdata.h.

Referenced by createMultiLineFromFragments(), createMultiPointFromFragments(), createMultiPolygonFromFragments(), createPolygonFromFragments(), endElement(), and startElement().