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efff5f1670
This function sets a variable for parts of an expression, therefore avoiding to repeatedly recalculate complex values.
288 lines
8.7 KiB
Plaintext
288 lines
8.7 KiB
Plaintext
/************************************************************************
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* This file has been generated automatically from *
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* *
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* src/core/expression/qgsexpressionfunction.h *
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* *
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* Do not edit manually ! Edit header and run scripts/sipify.pl again *
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************************************************************************/
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class QgsExpressionFunction
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{
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%Docstring
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A abstract base class for defining QgsExpression functions.
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%End
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%TypeHeaderCode
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#include "qgsexpressionfunction.h"
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%End
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public:
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class Parameter
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{
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%Docstring
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Represents a single parameter passed to a function.
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.. versionadded:: 2.16
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%End
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%TypeHeaderCode
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#include "qgsexpressionfunction.h"
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%End
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public:
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Parameter( const QString &name,
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bool optional = false,
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const QVariant &defaultValue = QVariant() );
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%Docstring
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Constructor for Parameter.
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\param name parameter name, used when named parameter are specified in an expression
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\param optional set to true if parameter should be optional
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\param defaultValue default value to use for optional parameters
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%End
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QString name() const;
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%Docstring
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Returns the name of the parameter.
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:rtype: str
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%End
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bool optional() const;
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%Docstring
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Returns true if the parameter is optional.
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:rtype: bool
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%End
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QVariant defaultValue() const;
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%Docstring
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Returns the default value for the parameter.
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:rtype: QVariant
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%End
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bool operator==( const QgsExpressionFunction::Parameter &other ) const;
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};
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typedef QList< QgsExpressionFunction::Parameter > ParameterList;
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QgsExpressionFunction( const QString &fnname,
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int params,
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const QString &group,
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const QString &helpText = QString(),
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bool lazyEval = false,
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bool handlesNull = false,
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bool isContextual = false );
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%Docstring
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Constructor for function which uses unnamed parameters
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%End
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QgsExpressionFunction( const QString &fnname,
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int params,
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const QStringList &groups,
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const QString &helpText = QString(),
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bool lazyEval = false,
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bool handlesNull = false,
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bool isContextual = false );
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%Docstring
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Constructor for function which uses unnamed parameters and group list
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.. versionadded:: 3.0
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%End
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QgsExpressionFunction( const QString &fnname,
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const QgsExpressionFunction::ParameterList ¶ms,
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const QString &group,
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const QString &helpText = QString(),
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bool lazyEval = false,
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bool handlesNull = false,
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bool isContextual = false );
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%Docstring
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Constructor for function which uses named parameter list.
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.. versionadded:: 2.16
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%End
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QgsExpressionFunction( const QString &fnname,
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const QgsExpressionFunction::ParameterList ¶ms,
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const QStringList &groups,
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const QString &helpText = QString(),
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bool lazyEval = false,
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bool handlesNull = false,
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bool isContextual = false );
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%Docstring
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Constructor for function which uses named parameter list and group list.
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.. versionadded:: 3.0
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%End
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virtual ~QgsExpressionFunction();
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QString name() const;
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%Docstring
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The name of the function.
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:rtype: str
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%End
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int params() const;
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%Docstring
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The number of parameters this function takes.
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:rtype: int
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%End
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int minParams() const;
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%Docstring
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The minimum number of parameters this function takes.
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:rtype: int
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%End
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const QgsExpressionFunction::ParameterList ¶meters() const;
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%Docstring
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Returns the list of named parameters for the function, if set.
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.. versionadded:: 2.16
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:rtype: QgsExpressionFunction.ParameterList
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%End
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virtual bool usesGeometry( const QgsExpressionNodeFunction *node ) const;
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%Docstring
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Does this function use a geometry object.
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:rtype: bool
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%End
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virtual QStringList aliases() const;
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%Docstring
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Returns a list of possible aliases for the function. These include
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other permissible names for the function, e.g., deprecated names.
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:return: list of known aliases
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.. versionadded:: 2.9
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:rtype: list of str
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%End
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bool lazyEval() const;
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%Docstring
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True if this function should use lazy evaluation. Lazy evaluation functions take QgsExpression.Node objects
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rather than the node results when called. You can use node->eval(parent, feature) to evaluate the node and return the result
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Functions are non lazy default and will be given the node return value when called.
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:rtype: bool
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%End
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virtual bool isStatic( const QgsExpressionNodeFunction *node, QgsExpression *parent, const QgsExpressionContext *context ) const;
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%Docstring
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Will be called during prepare to determine if the function is static.
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A function is static if it will return the same value for every feature with different
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attributes and/or geometry.
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By default this will return true, if all arguments that have been passed to the function
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are also static.
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.. versionadded:: 3.0
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:rtype: bool
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%End
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virtual bool prepare( const QgsExpressionNodeFunction *node, QgsExpression *parent, const QgsExpressionContext *context ) const;
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%Docstring
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This will be called during the prepare step() of an expression if it is not static.
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This can be used by functions to do any preparation steps that might help to speedup the upcoming
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evaluation.
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.. versionadded:: 3.0
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:rtype: bool
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%End
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virtual QSet<QString> referencedColumns( const QgsExpressionNodeFunction *node ) const;
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%Docstring
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Returns a set of field names which are required for this function.
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May contain QgsFeatureRequest.AllAttributes to signal that all
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attributes are required.
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If in doubt this will return more fields than strictly required.
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.. versionadded:: 3.0
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:rtype: set of str
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%End
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bool isContextual() const;
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%Docstring
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Returns whether the function is only available if provided by a QgsExpressionContext object.
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.. versionadded:: 2.12
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:rtype: bool
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%End
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virtual bool isDeprecated() const;
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%Docstring
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Returns true if the function is deprecated and should not be presented as a valid option
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to users in expression builders.
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.. versionadded:: 3.0
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:rtype: bool
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%End
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QString group() const;
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%Docstring
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Returns the first group which the function belongs to.
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.. note::
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consider using groups() instead, as some functions naturally belong in multiple groups
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:rtype: str
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%End
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QStringList groups() const;
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%Docstring
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Returns a list of the groups the function belongs to.
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.. versionadded:: 3.0
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.. seealso:: group()
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:rtype: list of str
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%End
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const QString helpText() const;
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%Docstring
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The help text for the function.
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:rtype: str
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%End
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virtual QVariant func( const QVariantList &values, const QgsExpressionContext *context, QgsExpression *parent ) = 0;
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%Docstring
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Returns result of evaluating the function.
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\param values list of values passed to the function
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\param context context expression is being evaluated against
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\param parent parent expression
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:return: result of function
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:rtype: QVariant
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%End
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virtual QVariant run( QgsExpressionNode::NodeList *args, const QgsExpressionContext *context, QgsExpression *parent );
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%Docstring
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:rtype: QVariant
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%End
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bool operator==( const QgsExpressionFunction &other ) const;
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virtual bool handlesNull() const;
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%Docstring
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:rtype: bool
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%End
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protected:
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static bool allParamsStatic( const QgsExpressionNodeFunction *node, QgsExpression *parent, const QgsExpressionContext *context );
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%Docstring
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This will return true if all the params for the provided function ``node`` are static within the
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constraints imposed by the ``context`` within the given ``parent``.
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This can be used as callback for custom implementations of subclasses. It is the default for implementation
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for StaticFunction.isStatic.
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.. versionadded:: 3.0
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:rtype: bool
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%End
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};
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/************************************************************************
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* This file has been generated automatically from *
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* *
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* src/core/expression/qgsexpressionfunction.h *
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* *
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* Do not edit manually ! Edit header and run scripts/sipify.pl again *
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************************************************************************/
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