QGIS/python/core/qgsaggregatecalculator.sip

/************************************************************************
 * This file has been generated automatically from                      *
 *                                                                      *
 * src/core/qgsaggregatecalculator.h                                    *
 *                                                                      *
 * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
 ************************************************************************/






class QgsAggregateCalculator
{
%Docstring
 Utility class for calculating aggregates for a field (or expression) over the features
 from a vector layer. It is recommended that QgsVectorLayer.aggregate() is used rather then
 directly using this class, as the QgsVectorLayer method can handle delegating aggregate calculation
 to a data provider for remote calculation.
.. versionadded:: 2.16
%End

%TypeHeaderCode
#include "qgsaggregatecalculator.h"
%End
  public:

    enum Aggregate
    {
      Count,
      CountDistinct,
      CountMissing,
      Min,
      Max,
      Sum,
      Mean,
      Median,
      StDev,
      StDevSample,
      Range,
      Minority,
      Majority,
      FirstQuartile,
      ThirdQuartile,
      InterQuartileRange,
      StringMinimumLength,
      StringMaximumLength,
      StringConcatenate,
      GeometryCollect,
      ArrayAggregate
    };

    struct AggregateParameters
    {

      QString filter;
%Docstring
 Optional filter for calculating aggregate over a subset of features, or an
 empty string to use all features.
.. seealso:: QgsAggregateCalculator.setFilter()
.. seealso:: QgsAggregateCalculator.filter()
%End

      QString delimiter;
%Docstring
 Delimiter to use for joining values with the StringConcatenate aggregate.
.. seealso:: QgsAggregateCalculator.setDelimiter()
.. seealso:: QgsAggregateCalculator.delimiter()
%End
    };

    QgsAggregateCalculator( const QgsVectorLayer *layer );
%Docstring
 Constructor for QgsAggregateCalculator.
 \param layer vector layer to calculate aggregate from
%End

    const QgsVectorLayer *layer() const;
%Docstring
 Returns the associated vector layer.
 :rtype: QgsVectorLayer
%End

    void setParameters( const AggregateParameters &parameters );
%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:: filter()
%End

    QString filter() const;
%Docstring
 Returns the filter which limits the features used during the aggregate calculation.
.. seealso:: setFilter()
 :rtype: str
%End

    void setDelimiter( const QString &delimiter );
%Docstring
 Sets the delimiter to use for joining values with the StringConcatenate aggregate.
 \param delimiter string delimiter
.. seealso:: delimiter()
%End

    QString delimiter() const;
%Docstring
 Returns the delimiter used for joining values with the StringConcatenate aggregate.
.. seealso:: setDelimiter()
 :rtype: str
%End

    QVariant calculate( Aggregate aggregate, const QString &fieldOrExpression,
                        QgsExpressionContext *context = 0, bool *ok = 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
 :return: calculated aggregate value
 :rtype: QVariant
%End

    static 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
 :rtype: Aggregate
%End

};


/************************************************************************
 * This file has been generated automatically from                      *
 *                                                                      *
 * src/core/qgsaggregatecalculator.h                                    *
 *                                                                      *
 * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
 ************************************************************************/