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/************************************************************************
* This file has been generated automatically from *
* *
* src/core/qgsaggregatecalculator.h *
* *
* Do not edit manually ! Edit header and run scripts/sipify.py again *
************************************************************************/
class QgsAggregateCalculator
{
%Docstring(signature="appended")
Utility class for calculating aggregates for a field (or expression)
over the features from a vector layer.
.. note::
It is recommended that :py:func:`QgsVectorLayer.aggregate()` is used rather then
directly using this class, as the :py:class:`QgsVectorLayer` method can handle delegating aggregate calculation
to a data provider for remote calculation.
%End
%TypeHeaderCode
#include "qgsaggregatecalculator.h"
%End
public:
struct AggregateInfo
{
QString function;
QString name;
QSet<QMetaType::Type> supportedTypes;
};
struct AggregateParameters
{
QString filter;
QString delimiter;
QgsFeatureRequest::OrderBy orderBy;
};
QgsAggregateCalculator( const QgsVectorLayer *layer );
%Docstring
Constructor for QgsAggregateCalculator.
:param layer: vector layer to calculate aggregate from
%End
QString lastError() const;
%Docstring
Returns the last error encountered during the aggregate calculation.
.. versionadded:: 3.22
%End
const QgsVectorLayer *layer() const;
%Docstring
Returns the associated vector layer.
%End
void setParameters( const AggregateParameters ¶meters );
%Docstring
Sets all aggregate parameters from a parameter bundle.
:param parameters: aggregate parameters
%End
void setFilter( const QString &filterExpression );
%Docstring
Sets a filter to limit the features used during the aggregate
calculation.
:param filterExpression: expression for filtering features, or empty
string to remove filter
.. seealso:: :py:func:`filter`
%End
void setFidsFilter( const QgsFeatureIds &fids );
%Docstring
Sets a filter to limit the features used during the aggregate
calculation. If an expression filter is set, it will override this
filter.
:param fids: feature ids for feature filtering, and empty list will
return no features.
.. seealso:: :py:func:`filter`
%End
QString filter() const;
%Docstring
Returns the filter which limits the features used during the aggregate
calculation.
.. seealso:: :py:func:`setFilter`
%End
void setDelimiter( const QString &delimiter );
%Docstring
Sets the delimiter to use for joining values with the StringConcatenate
aggregate.
:param delimiter: string delimiter
.. seealso:: :py:func:`delimiter`
%End
QString delimiter() const;
%Docstring
Returns the delimiter used for joining values with the StringConcatenate
aggregate.
.. seealso:: :py:func:`setDelimiter`
%End
QVariant calculate( Qgis::Aggregate aggregate, const QString &fieldOrExpression,
QgsExpressionContext *context = 0, bool *ok = 0, QgsFeedback *feedback = 0 ) const;
%Docstring
Calculates the value of an aggregate.
:param aggregate: aggregate to calculate
:param fieldOrExpression: source field or expression to use as basis for
aggregated values. If an expression is used,
then the context parameter must be set.
:param context: expression context for evaluating expressions
:param ok: if specified, will be set to ``True`` if aggregate
calculation was successful. If ``ok`` is ``False`` then
:py:func:`~QgsAggregateCalculator.lastError` can be used to
retrieve a descriptive error message.
:param feedback: optional feedback argument for early cancellation
(since QGIS 3.22). If set, this will take precedence
over any feedback object set on the expression
``context``.
:return: calculated aggregate value
%End
static Qgis::Aggregate stringToAggregate( const QString &string, bool *ok = 0 );
%Docstring
Converts a string to a aggregate type.
:param string: string to convert
:param ok: if specified, will be set to ``True`` if conversion was
successful
:return: aggregate type
%End
static QString displayName( Qgis::Aggregate aggregate );
%Docstring
Returns the friendly display name for a ``aggregate``.
.. versionadded:: 3.22
%End
static QList< QgsAggregateCalculator::AggregateInfo > aggregates();
%Docstring
Structured information for available aggregates.
.. versionadded:: 3.2
%End
};
/************************************************************************
* This file has been generated automatically from *
* *
* src/core/qgsaggregatecalculator.h *
* *
* Do not edit manually ! Edit header and run scripts/sipify.py again *
************************************************************************/
|
