Class: QgsOgcUtils¶

Provides various utility functions for conversion between OGC (Open Geospatial Consortium) standards and QGIS internal representations.

Currently supported standards:

GML2 - Geography Markup Language (import, export)

class qgis.core.QgsOgcUtils[source]¶

Bases: object

class Context¶

Bases: object

The Context struct stores the current layer and coordinate transform context.

Added in version 3.14.

layer¶

transformContext¶

FILTER_FES_2_0 = 2¶

FILTER_OGC_1_0 = 0¶

FILTER_OGC_1_1 = 1¶

class FilterVersion¶: Bases: int

class GMLVersion¶: Bases: int

GML_2_1_2 = 0¶

GML_3_1_0 = 1¶

GML_3_2_1 = 2¶

static colorFromOgcFill(fillElement: QDomElement) → QColor[source]¶

Parse XML with OGC fill into QColor

Parameters:: fillElement (QDomElement)
Return type:: QColor

static elseFilterExpression(doc: QDomDocument) → QDomElement[source]¶

Creates an ElseFilter from doc

Return type:: QDomElement
Returns:: valid OGC ElseFilter QDomElement

Added in version 3.28.

Parameters:: doc (QDomDocument)

static expressionFromOgcFilter(element: QDomElement, layer: QgsVectorLayer | None = None) → QgsExpression | None[source]¶

Parse XML with OGC filter into QGIS expression

expressionFromOgcFilter(element: QDomElement, version: QgsOgcUtils.FilterVersion, layer: Optional[QgsVectorLayer] = None) -> Optional[QgsExpression] Returns an expression from a WFS filter embedded in a document.

Parameters:

element (QDomElement) – The WFS Filter
version – The WFS version
layer (Optional[QgsVectorLayer] = None) – Layer to use to retrieve field values from literal filters

Added in version 3.4.

Return type:: Optional[QgsExpression]

static expressionToOgcExpression(exp: QgsExpression, doc: QDomDocument, errorMessage: str | None | None = '', requiresFilterElement: bool = False) → QDomElement[source]¶

Creates an OGC expression XML element from the exp expression with default values for the geometry name, srs name, honourAsisOrientation and invertAxisOrientation.

Returns:: valid OGC expression QDomElement on success or a valid verbatim <Filter> endverbatim QDomElement when requiresFilterElement is set. otherwise null QDomElement

expressionToOgcExpression(exp: QgsExpression, doc: QDomDocument, gmlVersion: QgsOgcUtils.GMLVersion, filterVersion: QgsOgcUtils.FilterVersion, geometryName: Optional[str], srsName: Optional[str], honourAxisOrientation: bool, invertAxisOrientation: bool, errorMessage: Optional[Optional[str]] = ‘’, requiresFilterElement: bool = False, fieldNameToXPathMap: Dict[Optional[str], Optional[str]] = {}, namespacePrefixToUriMap: Dict[Optional[str], Optional[str]] = {}) -> QDomElement Creates an OGC expression XML element from the exp expression.

Return type:

QDomElement

Returns:

valid OGC expression QDomElement on success or a valid verbatim <Filter> endverbatim QDomElement when requiresFilterElement is set. otherwise null QDomElement

Parameters:

exp (QgsExpression)
doc (QDomDocument)
errorMessage (Optional[Optional[str]] = '')
requiresFilterElement (bool = False)

expressionToOgcFilter(exp: QgsExpression, doc: QDomDocument, errorMessage: str | None | None = '') → QDomElement[source]¶

Creates OGC filter XML element. Supports minimum standard filter according to the OGC filter specs (=,!=,<,>,<=,>=,AND,OR,NOT)

Return type:

QDomElement

Returns:

valid verbatim <Filter> endverbatim QDomElement on success, otherwise null QDomElement

Parameters:

exp (QgsExpression)
doc (QDomDocument)
errorMessage (Optional[Optional[str]] = '')

static geometryFromGML(xmlString: str | None, context: QgsOgcUtils.Context = QgsOgcUtils.Context()) → QgsGeometry[source]¶

Static method that creates geometry from GML

Parameters:

xmlString (Optional[str]) – xml representation of the geometry. GML elements are expected to be in default namespace (verbatim {<Point>…</Point> endverbatim) or in “gml” namespace (verbatim <gml:Point>…</gml:Point> endverbatim)
context (QgsOgcUtils.Context = QgsOgcUtils.Context()) – QgsOgcUtils context

geometryFromGML(geometryNode: QDomNode, context: QgsOgcUtils.Context = QgsOgcUtils.Context()) -> QgsGeometry Static method that creates geometry from GML

Return type:: QgsGeometry

static geometryToGML(geometry: QgsGeometry, doc: QDomDocument, gmlVersion: QgsOgcUtils.GMLVersion, srsName: str | None, invertAxisOrientation: bool, gmlIdBase: str | None, precision: int = 17) → QDomElement[source]¶

Exports the geometry to GML

Returns:: QDomElement

geometryToGML(geometry: QgsGeometry, doc: QDomDocument, format: Optional[str], precision: int = 17) -> QDomElement Exports the geometry to GML2 or GML3

Returns:: QDomElement

geometryToGML(geometry: QgsGeometry, doc: QDomDocument, precision: int = 17) -> QDomElement Exports the geometry to GML2

Return type:

QDomElement

Returns:

QDomElement

Parameters:

geometry (QgsGeometry)
doc (QDomDocument)
gmlVersion (QgsOgcUtils.GMLVersion)
srsName (Optional[str])
invertAxisOrientation (bool)
gmlIdBase (Optional[str])
precision (int = 17)

static rectangleFromGMLBox(boxNode: QDomNode) → QgsRectangle[source]¶

Read rectangle from GML2 Box

Parameters:: boxNode (QDomNode)
Return type:: QgsRectangle

static rectangleFromGMLEnvelope(envelopeNode: QDomNode) → QgsRectangle[source]¶

Read rectangle from GML3 Envelope

Parameters:: envelopeNode (QDomNode)
Return type:: QgsRectangle

static rectangleToGMLBox(box: QgsRectangle | None, doc: QDomDocument, precision: int = 17) → QDomElement[source]¶

Exports the rectangle to GML2 Box

Returns:: QDomElement

rectangleToGMLBox(box: Optional[QgsRectangle], doc: QDomDocument, srsName: Optional[str], invertAxisOrientation: bool, precision: int = 17) -> QDomElement Exports the rectangle to GML2 Box

Return type:

QDomElement

Returns:

QDomElement

Parameters:

box (Optional[QgsRectangle])
doc (QDomDocument)
precision (int = 17)

static rectangleToGMLEnvelope(env: QgsRectangle | None, doc: QDomDocument, precision: int = 17) → QDomElement[source]¶

Exports the rectangle to GML3 Envelope

Returns:: QDomElement

rectangleToGMLEnvelope(env: Optional[QgsRectangle], doc: QDomDocument, srsName: Optional[str], invertAxisOrientation: bool, precision: int = 17) -> QDomElement Exports the rectangle to GML3 Envelope

Return type:

QDomElement

Returns:

QDomElement

Parameters:

env (Optional[QgsRectangle])
doc (QDomDocument)
precision (int = 17)