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/************************************************************************
* This file has been generated automatically from *
* *
* src/core/qgsfeaturerequest.h *
* *
* Do not edit manually ! Edit header and run scripts/sipify.py again *
************************************************************************/
class QgsFeatureRequest
{
%Docstring(signature="appended")
This class wraps a request for features to a vector layer (or directly
its vector data provider).
The request may apply an attribute/ID filter to fetch only a particular
subset of features. Currently supported filters:
- no filter - all features are returned
- feature id - only feature that matches given feature id is returned
- feature ids - only features that match any of the given feature ids
are returned
- filter expression - only features that match the given filter
expression are returned
Additionally a spatial filter can be set in combination with the
attribute/ID filter. Supported spatial filters are:
- :py:class:`Qgis`.SpatialFilterType.BoundingBox: Only features that intersect a given rectangle will be fetched. For the sake of speed, the intersection is often done only using feature's bounding box. There is a flag ExactIntersect that makes sure that only intersecting features will be returned.
- :py:class:`Qgis`.SpatialFilterType.DistanceWithin: Only features within a specified distance of a reference geometry will be fetched.
For efficiency, it is also possible to tell provider that some data is
not required:
- NoGeometry flag
- SubsetOfAttributes flag
- SimplifyMethod for geometries to fetch
The options may be chained, e.g.:
.. code-block:: python
QgsFeatureRequest().setFilterRect(QgsRectangle(0,0,1,1)).setFlags(QgsFeatureRequest.ExactIntersect)
Examples:
.. code-block:: python
# fetch all features:
QgsFeatureRequest()
# fetch all features, only one attribute
QgsFeatureRequest().setSubsetOfAttributes(['myfield'], layer.fields())
# fetch all features, without geometries
QgsFeatureRequest().setFlags(QgsFeatureRequest.NoGeometry)
# fetch only features from particular extent
QgsFeatureRequest().setFilterRect(QgsRectangle(0,0,1,1))
# fetch only features from particular extent, where the 'type' attribute is equal to 'road':
QgsFeatureRequest().setFilterRect(QgsRectangle(0,0,1,1)).setFilterExpression('"type"=\'road\'')
# fetch only one feature
QgsFeatureRequest().setFilterFid(45)
# fetch features within 50 map units of a linestring geometry
QgsFeatureRequest().setDistanceWithin(QgsGeometry.fromWkt('LineString(0 0, 10 0, 12 1)'), 50)
%End
%TypeHeaderCode
#include "qgsfeaturerequest.h"
%End
public:
class OrderByClause
{
%Docstring(signature="appended")
The OrderByClause class represents an order by clause for a
QgsFeatureRequest.
It can be a simple field or an expression. Multiple order by clauses can
be added to a QgsFeatureRequest to fine tune the behavior if a single
field or expression is not enough to completely specify the required
behavior.
If expression compilation is activated in the settings and the
expression can be translated for the provider in question, it will be
evaluated on provider side. If one of these two premises does not apply,
the ordering will take place locally which results in increased memory
and CPU usage.
If the ordering is done on strings, the order depends on the system's
locale if the local fallback implementation is used. The order depends
on the server system's locale and implementation if ordering is done on
the server.
In case the fallback code needs to be used, a limit set on the request
will be respected for the features returned by the iterator but
internally all features will be requested from the provider.
%End
%TypeHeaderCode
#include "qgsfeaturerequest.h"
%End
public:
OrderByClause( const QString &expression, bool ascending = true );
%Docstring
Creates a new OrderByClause for a :py:class:`QgsFeatureRequest`
:param expression: The expression to use for ordering
:param ascending: If the order should be ascending (1,2,3) or descending
(3,2,1) If the order is ascending, by default nulls
are last If the order is descending, by default nulls
are first
%End
OrderByClause( const QString &expression, bool ascending, bool nullsfirst );
%Docstring
Creates a new OrderByClause for a :py:class:`QgsFeatureRequest`
:param expression: The expression to use for ordering
:param ascending: If the order should be ascending (1,2,3) or descending
(3,2,1)
:param nullsfirst: If ``True``, NULLS are at the beginning, if
``False``, NULLS are at the end
%End
OrderByClause( const QgsExpression &expression, bool ascending = true );
%Docstring
Creates a new OrderByClause for a :py:class:`QgsFeatureRequest`
:param expression: The expression to use for ordering
:param ascending: If the order should be ascending (1,2,3) or descending
(3,2,1) If the order is ascending, by default nulls
are last If the order is descending, by default nulls
are first
%End
OrderByClause( const QgsExpression &expression, bool ascending, bool nullsfirst );
%Docstring
Creates a new OrderByClause for a :py:class:`QgsFeatureRequest`
:param expression: The expression to use for ordering
:param ascending: If the order should be ascending (1,2,3) or descending
(3,2,1)
:param nullsfirst: If ``True``, NULLS are at the beginning, if
``False``, NULLS are at the end
%End
QgsExpression expression() const;
%Docstring
The expression
:return: the expression
%End
bool prepare( QgsExpressionContext *context );
%Docstring
Prepare the expression with the given context.
.. seealso:: :py:func:`QgsExpression.prepare`
%End
bool ascending() const;
%Docstring
Order ascending
:return: If ascending order is requested
%End
void setAscending( bool ascending );
%Docstring
Set if ascending order is requested
%End
bool nullsFirst() const;
%Docstring
Set if NULLS should be returned first
:return: if NULLS should be returned first
%End
void setNullsFirst( bool nullsFirst );
%Docstring
Set if NULLS should be returned first
%End
QString dump() const;
%Docstring
Dumps the content to an SQL equivalent
%End
bool operator==( const OrderByClause &v ) const;
bool operator!=( const OrderByClause &v ) const;
};
class OrderBy
{
%Docstring(signature="appended")
Represents a list of OrderByClauses, with the most important first and
the least important last.
%End
%TypeHeaderCode
#include "qgsfeaturerequest.h"
%End
public:
OrderBy();
%Docstring
Create a new empty order by
%End
OrderBy( const QList<QgsFeatureRequest::OrderByClause> &other );
%Docstring
Create a new order by from a list of clauses
%End
bool operator==( const OrderBy &v ) const;
bool operator!=( const OrderBy &v ) const;
QList<QgsFeatureRequest::OrderByClause> list() const;
%Docstring
Gets a copy as a list of OrderByClauses
This is only required in Python where the inheritance is not properly
propagated and this makes it usable.
%End
void save( QDomElement &elem ) const;
%Docstring
Serialize to XML
%End
void load( const QDomElement &elem );
%Docstring
Deserialize from XML
%End
QSet<QString> usedAttributes() const;
%Docstring
Returns a set of used attributes
.. note::
The returned attributes names are NOT guaranteed to be valid.
%End
QSet<int> usedAttributeIndices( const QgsFields &fields ) const;
%Docstring
Returns a set of used, validated attribute indices
.. versionadded:: 3.8
%End
QString dump() const;
%Docstring
Dumps the content to an SQL equivalent syntax
%End
};
static const QString ALL_ATTRIBUTES;
QgsFeatureRequest();
%Docstring
construct a default request: for all features get attributes and
geometries
%End
explicit QgsFeatureRequest( QgsFeatureId fid );
%Docstring
construct a request with feature ID filter
%End
explicit QgsFeatureRequest( const QgsFeatureIds &fids );
%Docstring
construct a request with feature ID filter
%End
explicit QgsFeatureRequest( const QgsRectangle &rectangle );
%Docstring
Construct a request with ``rectangle`` bounding box filter.
When a destination CRS is set using
:py:func:`~QgsFeatureRequest.setDestinationCrs`, ``rectangle`` is
expected to be in the same CRS as the
:py:func:`~QgsFeatureRequest.destinationCrs`. Otherwise, ``rectangle``
should use the same CRS as the source layer/provider.
%End
explicit QgsFeatureRequest( const QgsExpression &expr, const QgsExpressionContext &context = QgsExpressionContext() );
%Docstring
construct a request with a filter expression
%End
QgsFeatureRequest( const QgsFeatureRequest &rh );
bool compare( const QgsFeatureRequest &other ) const;
%Docstring
Compare two requests for equality, ignoring Expression Context,
Transform Error Callback, Feedback and Invalid Geometry Callback
:param other: the other request
:return: ``True`` if the requests are equal in all respects but without
checking for Expression Context, Transform Error, Feedback and
Invalid Geometry Callback
.. versionadded:: 3.38
%End
~QgsFeatureRequest();
Qgis::FeatureRequestFilterType filterType() const;
%Docstring
Returns the attribute/ID filter type which is currently set on this
request.
This type will automatically be set to the appropriate value whenever
:py:func:`~QgsFeatureRequest.setFilterFid`,
:py:func:`~QgsFeatureRequest.setFilterFids`,
:py:func:`~QgsFeatureRequest.setFilterExpression` or
:py:func:`~QgsFeatureRequest.disableFilter` are called.
.. note::
A feature request may have both an attribute/ID filter AND a spatial filter
set. See :py:func:`~QgsFeatureRequest.spatialFilterType` to retrieve the spatial filter.
.. seealso:: :py:func:`spatialFilterType`
%End
Qgis::SpatialFilterType spatialFilterType() const;
%Docstring
Returns the spatial filter type which is currently set on this request.
This type will automatically be set to the appropriate value whenever
:py:func:`~QgsFeatureRequest.setFilterRect`, or
:py:func:`~QgsFeatureRequest.setDistanceWithin` are called.
.. note::
A feature request may have both an attribute/ID filter AND a spatial filter
set. See :py:func:`~QgsFeatureRequest.filterType` to retrieve the attribute/ID filter.
.. seealso:: :py:func:`filterType`
.. versionadded:: 3.22
%End
QgsFeatureRequest &setFilterRect( const QgsRectangle &rectangle );
%Docstring
Sets the ``rectangle`` from which features will be taken. An empty
rectangle removes the filter.
When a destination CRS is set using
:py:func:`~QgsFeatureRequest.setDestinationCrs`, ``rectangle`` is
expected to be in the same CRS as the
:py:func:`~QgsFeatureRequest.destinationCrs`. Otherwise, ``rectangle``
should use the same CRS as the source layer/provider.
Calling this method will automatically set
:py:func:`~QgsFeatureRequest.spatialFilterType` to
:py:class:`Qgis`.SpatialFilterType.BoundingBox. If ``rectangle`` is a
null rectangle then :py:func:`~QgsFeatureRequest.spatialFilterType` will
be reset to :py:class:`Qgis`.SpatialFilterType.NoFilter.
.. seealso:: :py:func:`filterRect`
%End
QgsRectangle filterRect() const;
%Docstring
Returns the rectangle from which features will be taken. If the returned
rectangle is null, then no filter rectangle is set.
If :py:func:`~QgsFeatureRequest.spatialFilterType` is
:py:class:`Qgis`.SpatialFilterType.BoundingBox then only features from
within this bounding box will be fetched. If
:py:func:`~QgsFeatureRequest.spatialFilterType` is
:py:class:`Qgis`.SpatialFilterType.DistanceWithin then the returned
rectangle represents the bounding box of the
:py:func:`~QgsFeatureRequest.referenceGeometry` extended by
:py:func:`~QgsFeatureRequest.distanceWithin`.
When a destination CRS is set using
:py:func:`~QgsFeatureRequest.setDestinationCrs`, the rectangle will be
in the same CRS as the :py:func:`~QgsFeatureRequest.destinationCrs`.
Otherwise, the rectangle will use the same CRS as the source
layer/provider.
.. seealso:: :py:func:`setFilterRect`
%End
QgsFeatureRequest &setDistanceWithin( const QgsGeometry &geometry, double distance );
%Docstring
Sets a reference ``geometry`` and a maximum ``distance`` from this
geometry to retrieve features within.
When a destination CRS is set using
:py:func:`~QgsFeatureRequest.setDestinationCrs`, ``geometry`` is
expected to be in the same CRS as the
:py:func:`~QgsFeatureRequest.destinationCrs` and ``distance`` is in the
spatial units of the :py:func:`~QgsFeatureRequest.destinationCrs`.
Otherwise, ``geometry`` should use the same CRS as the source
layer/provider and ``distance`` should use the spatial units as this
same CRS.
Calling this method will automatically set
:py:func:`~QgsFeatureRequest.spatialFilterType` to
:py:class:`Qgis`.SpatialFilterType.DistanceWithin.
.. seealso:: :py:func:`filterRect`
.. versionadded:: 3.22
%End
QgsGeometry referenceGeometry() const;
%Docstring
Returns the reference geometry used for spatial filtering of features.
When :py:func:`~QgsFeatureRequest.spatialFilterType` is
:py:class:`Qgis`.SpatialFilterType.DistanceWithin then only features
within :py:func:`~QgsFeatureRequest.distanceWithin` units of the
reference geometry will be fetched.
When a destination CRS is set using
:py:func:`~QgsFeatureRequest.setDestinationCrs`, the geometry will be in
the same CRS as the :py:func:`~QgsFeatureRequest.destinationCrs`.
Otherwise, the geometry will use the same CRS as the source
layer/provider.
.. seealso:: :py:func:`setDistanceWithin`
.. versionadded:: 3.22
%End
double distanceWithin() const;
%Docstring
Returns the maximum distance from the
:py:func:`~QgsFeatureRequest.referenceGeometry` of fetched features, if
:py:func:`~QgsFeatureRequest.spatialFilterType` is
:py:class:`Qgis`.SpatialFilterType.DistanceWithin.
When a destination CRS is set using
:py:func:`~QgsFeatureRequest.setDestinationCrs`, the distance will be in
the spatial units of :py:func:`~QgsFeatureRequest.destinationCrs`.
Otherwise, the distance will use the same units as the CRS of the source
layer/provider.
.. seealso:: :py:func:`setDistanceWithin`
.. versionadded:: 3.22
%End
QgsFeatureRequest &setFilterFid( QgsFeatureId fid );
%Docstring
Sets the feature ID that should be fetched.
Calling this method will automatically set
:py:func:`~QgsFeatureRequest.filterType` to QgsFeatureRequest.FilterFid.
.. seealso:: :py:func:`filterFid`
.. seealso:: :py:func:`setFilterFids`
%End
QgsFeatureId filterFid() const;
%Docstring
Returns the feature ID that should be fetched.
.. seealso:: :py:func:`setFilterFid`
.. seealso:: :py:func:`filterFids`
%End
QgsFeatureRequest &setFilterFids( const QgsFeatureIds &fids );
%Docstring
Sets the feature IDs that should be fetched.
Calling this method will automatically set
:py:func:`~QgsFeatureRequest.filterType` to
QgsFeatureRequest.FilterFids.
.. seealso:: :py:func:`filterFids`
.. seealso:: :py:func:`setFilterFid`
%End
const QgsFeatureIds &filterFids() const;
%Docstring
Returns the feature IDs that should be fetched.
.. seealso:: :py:func:`setFilterFids`
.. seealso:: :py:func:`filterFid`
%End
QgsFeatureRequest &setInvalidGeometryCheck( Qgis::InvalidGeometryCheck check );
%Docstring
Sets invalid geometry checking behavior.
.. note::
Invalid geometry checking is not performed when retrieving features
directly from a :py:class:`QgsVectorDataProvider`.
.. seealso:: :py:func:`invalidGeometryCheck`
%End
Qgis::InvalidGeometryCheck invalidGeometryCheck() const;
%Docstring
Returns the invalid geometry checking behavior.
.. seealso:: :py:func:`setInvalidGeometryCheck`
%End
QgsFeatureRequest &setInvalidGeometryCallback( SIP_PYCALLABLE / AllowNone / );
%Docstring
Sets a callback function to use when encountering an invalid geometry
and :py:func:`~QgsFeatureRequest.invalidGeometryCheck` is set to
GeometryAbortOnInvalid or GeometrySkipInvalid. This function will be
called using the feature with invalid geometry as a parameter.
.. seealso:: :py:func:`invalidGeometryCallback`
%End
%MethodCode
Py_BEGIN_ALLOW_THREADS
sipCpp->setInvalidGeometryCallback( [a0]( const QgsFeature &arg )
{
SIP_BLOCK_THREADS
Py_XDECREF( sipCallMethod( NULL, a0, "D", &arg, sipType_QgsFeature, NULL ) );
SIP_UNBLOCK_THREADS
} );
sipRes = sipCpp;
Py_END_ALLOW_THREADS
%End
QgsFeatureRequest &setFilterExpression( const QString &expression );
%Docstring
Set the filter ``expression``. {:py:class:`QgsExpression`}
:param expression: expression string
Calling this method will automatically set
:py:func:`~QgsFeatureRequest.filterType` to
QgsFeatureRequest.FilterExpression.
.. seealso:: :py:func:`filterExpression`
.. seealso:: :py:func:`setExpressionContext`
%End
QgsExpression *filterExpression() const;
%Docstring
Returns the filter expression (if set).
.. seealso:: :py:func:`setFilterExpression`
.. seealso:: :py:func:`expressionContext`
%End
QgsFeatureRequest &combineFilterExpression( const QString &expression );
%Docstring
Modifies the existing filter expression to add an additional expression
filter. The filter expressions are combined using AND, so only features
matching both the existing expression and the additional expression will
be returned.
Calling this method will automatically set
:py:func:`~QgsFeatureRequest.filterType` to
QgsFeatureRequest.FilterExpression.
%End
QgsExpressionContext *expressionContext();
%Docstring
Returns the expression context used to evaluate filter expressions.
.. seealso:: :py:func:`setExpressionContext`
.. seealso:: :py:func:`filterExpression`
%End
QgsFeatureRequest &setExpressionContext( const QgsExpressionContext &context );
%Docstring
Sets the expression context used to evaluate filter expressions.
.. seealso:: :py:func:`expressionContext`
.. seealso:: :py:func:`setFilterExpression`
%End
QgsFeatureRequest &disableFilter();
%Docstring
Disables any attribute/ID filtering.
Calling this method will automatically set
:py:func:`~QgsFeatureRequest.filterType` to
QgsFeatureRequest.FilterNone.
.. note::
Spatial filters will be left in place.
:return: The object the method is called on for chaining
%End
QgsFeatureRequest &addOrderBy( const QString &expression, bool ascending = true );
%Docstring
Adds a new OrderByClause, appending it as the least important one.
:param expression: The expression to use for ordering
:param ascending: If the order should be ascending (1,2,3) or descending
(3,2,1) If the order is ascending, by default nulls
are last If the order is descending, by default nulls
are first
%End
QgsFeatureRequest &addOrderBy( const QString &expression, bool ascending, bool nullsfirst );
%Docstring
Adds a new OrderByClause, appending it as the least important one.
:param expression: The expression to use for ordering
:param ascending: If the order should be ascending (1,2,3) or descending
(3,2,1)
:param nullsfirst: If ``True``, NULLS are at the beginning, if
``False``, NULLS are at the end
%End
OrderBy orderBy() const;
%Docstring
Returns a list of order by clauses specified for this feature request.
%End
QgsFeatureRequest &setOrderBy( const OrderBy &orderBy );
%Docstring
Set a list of order by clauses.
%End
QgsFeatureRequest &setLimit( long long limit );
%Docstring
Set the maximum number of features to request.
:param limit: maximum number of features, or -1 to request all features.
.. seealso:: :py:func:`limit`
%End
long long limit() const;
%Docstring
Returns the maximum number of features to request, or -1 if no limit
set.
.. seealso:: :py:func:`setLimit`
%End
QgsFeatureRequest &setFlags( Qgis::FeatureRequestFlags flags );
%Docstring
Sets ``flags`` that affect how features will be fetched.
.. seealso:: :py:func:`flags`
%End
Qgis::FeatureRequestFlags flags() const;
%Docstring
Returns the flags which affect how features are fetched.
.. seealso:: :py:func:`setFlags`
%End
QgsFeatureRequest &setSubsetOfAttributes( const QgsAttributeList &attrs );
%Docstring
Set a subset of attributes that will be fetched.
An empty attributes list indicates that no attributes will be fetched.
To revert a call to setSubsetOfAttributes and fetch all available
attributes, the SubsetOfAttributes flag should be removed from the
request.
.. note::
This is intended as hint to data providers for optimising feature retrieval. Depending
on the provider, it may be trivial for the provider to always return all attributes instead of
the requested subset, or actually result in slower retrieval when the attributes are filtered out.
In these cases the provider may ignore this hint and return all attributes regardless of the
requested attributes.
.. seealso:: :py:func:`subsetOfAttributes`
.. seealso:: :py:func:`setNoAttributes`
%End
QgsFeatureRequest &setNoAttributes();
%Docstring
Set that no attributes will be fetched.
To revert a call to setNoAttributes and fetch all or some available
attributes, the SubsetOfAttributes flag should be removed from the
request.
.. note::
This is intended as hint to data providers for optimising feature retrieval. Depending
on the provider, it may be trivial for the provider to always return all attributes instead of
removing them. In these cases the provider may ignore this hint and return all attributes
regardless of whether this method has been called.
.. seealso:: :py:func:`setSubsetOfAttributes`
.. versionadded:: 3.4
%End
QgsAttributeList subsetOfAttributes() const;
%Docstring
Returns the subset of attributes which at least need to be fetched.
:return: A list of attributes to be fetched
.. note::
This is intended as hint to data providers for optimising feature retrieval. Depending
on the provider, it may be trivial for the provider to always return all attributes instead of
the requested subset, or actually result in slower retrieval when the attributes are filtered out.
In these cases the provider may ignore this hint and return all attributes regardless of the
requested attributes.
.. seealso:: :py:func:`setSubsetOfAttributes`
.. seealso:: :py:func:`setNoAttributes`
%End
QgsFeatureRequest &setSubsetOfAttributes( const QStringList &attrNames, const QgsFields &fields );
%Docstring
Sets a subset of attributes by names that will be fetched.
.. note::
This is intended as hint to data providers for optimising feature retrieval. Depending
on the provider, it may be trivial for the provider to always return all attributes instead of
the requested subset, or actually result in slower retrieval when the attributes are filtered out.
In these cases the provider may ignore this hint and return all attributes regardless of the
requested attributes.
.. seealso:: :py:func:`subsetOfAttributes`
%End
QgsFeatureRequest &setSubsetOfAttributes( const QSet<QString> &attrNames, const QgsFields &fields );
%Docstring
Sets a subset of attributes by names that will be fetched.
.. note::
This is intended as hint to data providers for optimising feature retrieval. Depending
on the provider, it may be trivial for the provider to always return all attributes instead of
the requested subset, or actually result in slower retrieval when the attributes are filtered out.
In these cases the provider may ignore this hint and return all attributes regardless of the
requested attributes.
.. seealso:: :py:func:`subsetOfAttributes`
%End
QgsFeatureRequest &setSimplifyMethod( const QgsSimplifyMethod &simplifyMethod );
%Docstring
Set a simplification method for geometries that will be fetched.
.. seealso:: :py:func:`simplifyMethod`
%End
const QgsSimplifyMethod &simplifyMethod() const;
%Docstring
Returns the simplification method for geometries that will be fetched.
.. seealso:: :py:func:`setSimplifyMethod`
%End
QgsCoordinateTransform coordinateTransform() const;
%Docstring
Returns the coordinate transform which will be used to transform the
feature's geometries.
If this transform is valid then it will always be used to transform
features, regardless of the :py:func:`~QgsFeatureRequest.destinationCrs`
setting or the underlying feature source's actual CRS.
.. seealso:: :py:func:`setCoordinateTransform`
.. versionadded:: 3.40
%End
QgsCoordinateReferenceSystem destinationCrs() const;
%Docstring
Returns the destination coordinate reference system for feature's
geometries, or an invalid :py:class:`QgsCoordinateReferenceSystem` if no
reprojection will be done and all features will be left with their
original geometry.
.. warning::
if :py:func:`~QgsFeatureRequest.coordinateTransform` returns a valid transform then the
:py:func:`~QgsFeatureRequest.destinationCrs` will have no effect, and the :py:func:`~QgsFeatureRequest.coordinateTransform` will
always be used to transform features.
.. seealso:: :py:func:`calculateTransform`
.. seealso:: :py:func:`setDestinationCrs`
.. seealso:: :py:func:`transformContext`
%End
QgsCoordinateTransformContext transformContext() const;
%Docstring
Returns the transform context, for use when a
:py:func:`~QgsFeatureRequest.destinationCrs` has been set and
reprojection is required
.. seealso:: :py:func:`setDestinationCrs`
.. seealso:: :py:func:`destinationCrs`
%End
QgsCoordinateTransform calculateTransform( const QgsCoordinateReferenceSystem &sourceCrs ) const;
%Docstring
Calculates the coordinate transform to use to transform geometries when
they are originally in ``sourceCrs``.
This method will return
:py:func:`~QgsFeatureRequest.coordinateTransform` if it is set (ignoring
``sourceCrs``), otherwise it will calculate an appriopriate transform
from ``sourceCrs`` to :py:func:`~QgsFeatureRequest.destinationCrs`.
.. versionadded:: 3.40
%End
QgsFeatureRequest &setCoordinateTransform( const QgsCoordinateTransform &transform );
%Docstring
Sets the coordinate ``transform`` which will be used to transform the
feature's geometries.
If this transform is valid then it will always be used to transform
features, regardless of the :py:func:`~QgsFeatureRequest.destinationCrs`
setting or the underlying feature source's actual CRS.
When a ``transform`` is set using
:py:func:`~QgsFeatureRequest.setCoordinateTransform`, then any
:py:func:`~QgsFeatureRequest.filterRect` or
:py:func:`~QgsFeatureRequest.referenceGeometry` set on the request is
expected to be in the same CRS as the destination CRS for the
``transform``.
The feature geometry transformation is performed after all filter
expressions are tested and any virtual fields are calculated.
Accordingly, any geometric expressions used in
:py:func:`~QgsFeatureRequest.filterExpression` will be performed in the
original source CRS. This ensures consistent results are returned
regardless of the destination CRS. Similarly, virtual field values will
be calculated using the original geometry in the source CRS, so these
values are not affected by any destination CRS transform present in the
feature request.
.. warning::
This method should be used with caution, and it is recommended
to use the high-level :py:func:`~QgsFeatureRequest.setDestinationCrs` method instead. Setting a specific
transform should only be done when there is a requirement to use a particular
transform.
.. seealso:: :py:func:`coordinateTransform`
.. versionadded:: 3.40
%End
QgsFeatureRequest &setDestinationCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context );
%Docstring
Sets the destination ``crs`` for feature's geometries. If set, all
geometries will be reprojected from their original coordinate reference
system to this desired reference system. If ``crs`` is an invalid
:py:class:`QgsCoordinateReferenceSystem` then no reprojection will be
done and all features will be left with their original geometry.
When a ``crs`` is set using
:py:func:`~QgsFeatureRequest.setDestinationCrs`, then any
:py:func:`~QgsFeatureRequest.filterRect` or
:py:func:`~QgsFeatureRequest.referenceGeometry` set on the request is
expected to be in the same CRS as the destination CRS.
The feature geometry transformation to the destination CRS is performed
after all filter expressions are tested and any virtual fields are
calculated. Accordingly, any geometric expressions used in
:py:func:`~QgsFeatureRequest.filterExpression` will be performed in the
original source CRS. This ensures consistent results are returned
regardless of the destination CRS. Similarly, virtual field values will
be calculated using the original geometry in the source CRS, so these
values are not affected by any destination CRS transform present in the
feature request.
.. warning::
if :py:func:`~QgsFeatureRequest.coordinateTransform` returns a valid transform then the
:py:func:`~QgsFeatureRequest.destinationCrs` will have no effect, and the :py:func:`~QgsFeatureRequest.coordinateTransform` will
always be used to transform features.
.. seealso:: :py:func:`destinationCrs`
%End
QgsFeatureRequest &setTransformErrorCallback( SIP_PYCALLABLE / AllowNone / );
%Docstring
Sets a callback function to use when encountering a transform error when
iterating features and a :py:func:`~QgsFeatureRequest.destinationCrs` is
set. This function will be called using the feature which encountered
the transform error as a parameter.
.. seealso:: :py:func:`transformErrorCallback`
.. seealso:: :py:func:`setDestinationCrs`
%End
%MethodCode
Py_BEGIN_ALLOW_THREADS
sipCpp->setTransformErrorCallback( [a0]( const QgsFeature &arg )
{
SIP_BLOCK_THREADS
Py_XDECREF( sipCallMethod( NULL, a0, "D", &arg, sipType_QgsFeature, NULL ) );
SIP_UNBLOCK_THREADS
} );
sipRes = sipCpp;
Py_END_ALLOW_THREADS
%End
bool acceptFeature( const QgsFeature &feature );
%Docstring
Check if a feature is accepted by this requests filter
:param feature: The feature which will be tested
:return: ``True``, if the filter accepts the feature
%End
int connectionTimeout() const /Deprecated/;
%Docstring
Returns the timeout (in milliseconds) for how long we should wait for a
connection if none is available from the pool at this moment. A negative
value (which is set by default) will wait forever.
.. note::
Only works if the provider supports this option.
.. deprecated:: 3.40
Use :py:func:`~QgsFeatureRequest.timeout` instead.
%End
QgsFeatureRequest &setConnectionTimeout( int connectionTimeout ) /Deprecated/;
%Docstring
Sets the timeout (in milliseconds) for how long we should wait for a
connection if none is available from the pool at this moment. A negative
value (which is set by default) will wait forever.
.. note::
Only works if the provider supports this option.
.. deprecated:: 3.40
Use :py:func:`~QgsFeatureRequest.setTimeout` instead.
%End
int timeout() const;
%Docstring
Returns the timeout (in milliseconds) for the maximum time we should
wait during feature requests before a feature is returned. A negative
value (which is set by default) will wait forever.
.. note::
Only works if the provider supports this option.
.. seealso:: :py:func:`setTimeout`
.. versionadded:: 3.4
%End
QgsFeatureRequest &setTimeout( int timeout );
%Docstring
Sets the ``timeout`` (in milliseconds) for the maximum time we should
wait during feature requests before a feature is returned. A negative
value (which is set by default) will wait forever.
.. note::
Only works if the provider supports this option.
.. seealso:: :py:func:`timeout`
.. versionadded:: 3.4
%End
bool requestMayBeNested() const;
%Docstring
In case this request may be run nested within another already running
iteration on the same connection, set this to ``True``.
If this flag is ``True``, this request will be able to make use of
"spare" connections to avoid deadlocks.
For example, this should be set on requests that are issued from an
expression function.
.. seealso:: :py:func:`setRequestMayBeNested`
.. versionadded:: 3.4
%End
QgsFeatureRequest &setRequestMayBeNested( bool requestMayBeNested );
%Docstring
In case this request may be run nested within another already running
iteration on the same connection, set this to ``True``.
If this flag is ``True``, this request will be able to make use of
"spare" connections to avoid deadlocks.
For example, this should be set on requests that are issued from an
expression function.
.. seealso:: :py:func:`requestMayBeNested`
.. versionadded:: 3.4
%End
void setFeedback( QgsFeedback *feedback );
%Docstring
Attach a ``feedback`` object that can be queried regularly by the
iterator to check if it should be canceled.
Ownership of ``feedback`` is NOT transferred, and the caller must take
care that it exists for the lifetime of the feature request and feature
iterators.
.. seealso:: :py:func:`feedback`
.. versionadded:: 3.20
%End
QgsFeedback *feedback() const;
%Docstring
Returns the feedback object that can be queried regularly by the
iterator to check if it should be canceled, if set.
.. seealso:: :py:func:`setFeedback`
.. versionadded:: 3.20
%End
protected:
};
class QgsAbstractFeatureSource
{
%Docstring(signature="appended")
Base class that can be used for any class that is capable of returning
features
%End
%TypeHeaderCode
#include "qgsfeaturerequest.h"
%End
public:
virtual ~QgsAbstractFeatureSource();
virtual QgsFeatureIterator getFeatures( const QgsFeatureRequest &request = QgsFeatureRequest() ) = 0 /TransferBack/;
%Docstring
Gets an iterator for features matching the specified request
:param request: The request
:return: A feature iterator
%End
protected:
void iteratorOpened( QgsAbstractFeatureIterator *it );
void iteratorClosed( QgsAbstractFeatureIterator *it );
};
/************************************************************************
* This file has been generated automatically from *
* *
* src/core/qgsfeaturerequest.h *
* *
* Do not edit manually ! Edit header and run scripts/sipify.py again *
************************************************************************/
|