Class: QgsOgcUtils¶

The QgsOgcUtils class 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)

Methods

expressionToOgcFilter

Creates OGC filter XML element.

Static Methods

`colorFromOgcFill`	Parse XML with OGC fill into QColor
`elseFilterExpression`	Creates an ElseFilter from doc
`expressionFromOgcFilter`	Parse XML with OGC filter into QGIS expression
`expressionToOgcExpression`	Creates an OGC expression XML element from the exp expression with default values for the geometry name, srs name, honourAsisOrientation and invertAxisOrientation.
`geometryFromGML`	Static method that creates geometry from GML
`geometryToGML`	Exports the geometry to GML
`rectangleFromGMLBox`	Read rectangle from GML2 Box
`rectangleFromGMLEnvelope`	Read rectangle from GML3 Envelope
`rectangleToGMLBox`	Exports the rectangle to GML2 Box
`rectangleToGMLEnvelope`	Exports the rectangle to GML3 Envelope

Attributes

`FILTER_FES_2_0`
`FILTER_OGC_1_0`
`FILTER_OGC_1_1`
`GML_2_1_2`
`GML_3_1_0`
`GML_3_2_1`

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

Parameters:

element (QDomElement)
layer (Optional[QgsVectorLayer] = None)

Return type:

Optional[QgsExpression]

static expressionFromOgcFilter(element: QDomElement, version: QgsOgcUtils.FilterVersion, layer: QgsVectorLayer | None = None) → QgsExpression | None[source]

Returns an expression from a WFS filter embedded in a document.

Parameters:

element (QDomElement) – The WFS Filter
version (QgsOgcUtils.FilterVersion) – 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.

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)

static expressionToOgcExpression(exp: QgsExpression, doc: QDomDocument, gmlVersion: QgsOgcUtils.GMLVersion, filterVersion: QgsOgcUtils.FilterVersion, geometryName: str | None, srsName: str | None, honourAxisOrientation: bool, invertAxisOrientation: bool, errorMessage: str | None | None = '', requiresFilterElement: bool = False, fieldNameToXPathMap: Dict[str | None, str | None] = {}, namespacePrefixToUriMap: Dict[str | None, str | None] = {}) → QDomElement[source]

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)
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]] = {})

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

Return type:

QgsGeometry

static geometryFromGML(geometryNode: QDomNode, context: QgsOgcUtils.Context = QgsOgcUtils.Context()) → QgsGeometry[source]

Static method that creates geometry from GML

Parameters:

geometryNode (QDomNode)
context (QgsOgcUtils.Context = QgsOgcUtils.Context())

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

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 geometryToGML(geometry: QgsGeometry, doc: QDomDocument, format: str | None, precision: int = 17) → QDomElement[source]

Exports the geometry to GML2 or GML3

Return type:

QDomElement

Returns:

QDomElement

Parameters:

geometry (QgsGeometry)
doc (QDomDocument)
format (Optional[str])
precision (int = 17)

static geometryToGML(geometry: QgsGeometry, doc: QDomDocument, precision: int = 17) → QDomElement[source]

Exports the geometry to GML2

Return type:

QDomElement

Returns:

QDomElement

Parameters:

geometry (QgsGeometry)
doc (QDomDocument)
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

Return type:

QDomElement

Returns:

QDomElement

Parameters:

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

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

Exports the rectangle to GML2 Box

Return type:

QDomElement

Returns:

QDomElement

Parameters:

box (Optional[QgsRectangle])
doc (QDomDocument)
srsName (Optional[str])
invertAxisOrientation (bool)
precision (int = 17)

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

Exports the rectangle to GML3 Envelope

Return type:

QDomElement

Returns:

QDomElement

Parameters:

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

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

Exports the rectangle to GML3 Envelope

Return type:

QDomElement

Returns:

QDomElement

Parameters:

env (Optional[QgsRectangle])
doc (QDomDocument)
srsName (Optional[str])
invertAxisOrientation (bool)
precision (int = 17)