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

#include <qgsgml.h>

Collaboration diagram for QgsGml:

Signals
void	dataProgressAndSteps (int progress, int totalSteps)
void	dataReadProgress (int progress)
void	totalStepsUpdate (int totalSteps)
Public Member Functions
	QgsGml (const QString &typeName, const QString &geometryAttribute, const QgsFields &fields)
	~QgsGml ()
QMap< QgsFeatureId, QgsFeature * >	featuresMap () const
	Get parsed features for given type name.
int	getFeatures (const QString &uri, QGis::WkbType wkbType, QgsRectangle extent=0)
	Does the Http GET request to the wfs server.
int	getFeatures (const QByteArray &data, QGis::WkbType wkbType, QgsRectangle extent=0)
	Read from GML data.
QMap< QgsFeatureId, QString >	idsMap () const
	Get feature ids map.
Private Types
enum	ParseMode { none, boundingBox, feature, 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
void	calculateExtentFromFeatures ()
	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 QList< QgsPoint > &lineCoordinates) const
int	getPointWKB (unsigned char *wkb, int size, const QgsPoint &) const
int	getRingWKB (unsigned char *wkb, int size, const QList< QgsPoint > &ringCoordinates) const
ParseMode	modeStackPop ()
	Safely (if empty) pop from mode stack.
ParseMode	modeStackTop ()
	Get safely (if empty) top from mode stack.
int	pointsFromCoordinateString (QList< 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
QgsRectangle	mCurrentExtent
QgsFeature *	mCurrentFeature
QString	mCurrentFeatureId
unsigned char *	mCurrentWKB
	The total WKB for a feature.
QList< QList< unsigned char * > >	mCurrentWKBFragments
	WKB intermediate storage during parsing.
QList< QList< 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, map of feature maps for each feature type.
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.
QStack< ParseMode >	mParseModeStack
	Keep track about the most important nested elements.
QString	mStringCash
	This contains the character data if an important element has been encountered.
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 38 of file qgsgml.h.

Member Enumeration Documentation

enum QgsGml::ParseMode [private]

Enumerator:

none
boundingBox
feature
attribute
geometry
coordinate
point
line
polygon
multiPoint
multiLine
multiPolygon

Definition at line 81 of file qgsgml.h.

Constructor & Destructor Documentation

QgsGml::QgsGml	(	const QString &	typeName,
		const QString &	geometryAttribute,
		const QgsFields &	fields
	)

Definition at line 35 of file qgsgml.cpp.

References QgsApplication::endian(), mEndian, mThematicAttributes, mTypeName, and QgsFields::size().

QgsGml::~QgsGml ( )

Definition at line 61 of file qgsgml.cpp.

Member Function Documentation

void QgsGml::calculateExtentFromFeatures ( ) [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 830 of file qgsgml.cpp.

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

Referenced by getFeatures().

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

Definition at line 476 of file qgsgml.cpp.

References attribute, coordinate, mParseModeStack, and mStringCash.

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

Definition at line 110 of file qgsgml.h.

Referenced by getFeatures().

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

Creates a rectangle from a coordinate string.

Returns:: 0 in case of success

Definition at line 536 of file qgsgml.cpp.

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

Referenced by endElement().

int QgsGml::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 660 of file qgsgml.cpp.

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

Referenced by endElement().

int QgsGml::createMultiPointFromFragments ( ) [private]

Definition at line 694 of file qgsgml.cpp.

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

Referenced by endElement().

int QgsGml::createMultiPolygonFromFragments ( ) [private]

Definition at line 761 of file qgsgml.cpp.

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

Referenced by endElement().

int QgsGml::createPolygonFromFragments ( ) [private]

Definition at line 729 of file qgsgml.cpp.

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

Referenced by endElement().

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

Referenced by handleProgressEvent().

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

Referenced by getFeatures(), and handleProgressEvent().

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

Definition at line 106 of file qgsgml.h.

Referenced by getFeatures().

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

Definition at line 252 of file qgsgml.cpp.

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

QMap<QgsFeatureId, QgsFeature* > QgsGml::featuresMap ( ) const [inline]

Get parsed features for given type name.

Definition at line 61 of file qgsgml.h.

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

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

int QgsGml::getFeatures	(	const QString &	uri,
		QGis::WkbType *	wkbType,
		QgsRectangle *	extent = `0`
	)

Does the Http GET request to the wfs server.

Parameters:

uri	GML URL
wkbType	wkbType to retrieve
extent	retrieved extents

Returns:: 0 in case of success

Definition at line 65 of file qgsgml.cpp.

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

int QgsGml::getFeatures	(	const QByteArray &	data,
		QGis::WkbType *	wkbType,
		QgsRectangle *	extent = `0`
	)

Read from GML data.

Constructor uri param is ignored

Definition at line 132 of file qgsgml.cpp.

References chars(), end(), mExtent, mWkbType, NS_SEPARATOR, QgsDebugMsg, QgsRectangle::setMinimal(), and start().

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

Definition at line 605 of file qgsgml.cpp.

References mEndian, and QGis::WKBLineString.

Referenced by endElement().

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

Definition at line 585 of file qgsgml.cpp.

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

Referenced by endElement().

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

Definition at line 636 of file qgsgml.cpp.

Referenced by endElement().

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

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

Definition at line 156 of file qgsgml.cpp.

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

Referenced by getFeatures().

QMap<QgsFeatureId, QString > QgsGml::idsMap ( ) const [inline]

Get feature ids map.

Definition at line 64 of file qgsgml.h.

ParseMode QgsGml::modeStackPop ( ) [inline, private]

Safely (if empty) pop from mode stack.

Definition at line 158 of file qgsgml.h.

ParseMode QgsGml::modeStackTop ( ) [inline, private]

Get safely (if empty) top from mode stack.

Definition at line 155 of file qgsgml.h.

int QgsGml::pointsFromCoordinateString	(	QList< 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 554 of file qgsgml.cpp.

References mCoordinateSeparator, and mTupleSeparator.

Referenced by createBBoxFromCoordinateString(), and endElement().

QString QgsGml::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 522 of file qgsgml.cpp.

Referenced by startElement().

int QgsGml::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 491 of file qgsgml.cpp.

Referenced by startElement().

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

Definition at line 151 of file qgsgml.cpp.

References mFinished.

Referenced by getFeatures().

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

Definition at line 102 of file qgsgml.h.

Referenced by getFeatures().

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

XML handler methods.

Definition at line 167 of file qgsgml.cpp.

References attribute, boundingBox, coordinate, feature, 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 QgsGml::totalStepsUpdate ( int totalSteps ) [signal]

Referenced by getFeatures(), and handleProgressEvent().

int QgsGml::totalWKBFragmentSize ( ) const [private]

Adds all the integers contained in mCurrentWKBFragmentSizes.

Definition at line 817 of file qgsgml.cpp.

References mCurrentWKBFragmentSizes.

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

Member Data Documentation

QString QgsGml::mAttributeName [private]

Definition at line 198 of file qgsgml.h.

Referenced by endElement(), and startElement().

QString QgsGml::mCoordinateSeparator [private]

Coordinate separator for coordinate strings.

Usually ","

Definition at line 201 of file qgsgml.h.

Referenced by pointsFromCoordinateString(), and startElement().

QVector<QVariant> QgsGml::mCurrentAttributes [private]

Definition at line 186 of file qgsgml.h.

QgsRectangle QgsGml::mCurrentExtent [private]

Definition at line 193 of file qgsgml.h.

Referenced by endElement().

QgsFeature* QgsGml::mCurrentFeature [private]

Definition at line 185 of file qgsgml.h.

Referenced by endElement(), and startElement().

QString QgsGml::mCurrentFeatureId [private]

Definition at line 187 of file qgsgml.h.

Referenced by endElement(), and startElement().

unsigned char* QgsGml::mCurrentWKB [private]

The total WKB for a feature.

Definition at line 190 of file qgsgml.h.

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

QList< QList<unsigned char*> > QgsGml::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 195 of file qgsgml.h.

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