QGIS API Documentation  3.11.0-Master (68611307d7)
Public Member Functions | Static Public Member Functions | List of all members
QgsProcessingParameterExpression Class Reference

An expression parameter for processing algorithms. More...

#include <qgsprocessingparameters.h>

Inheritance diagram for QgsProcessingParameterExpression:
Inheritance graph
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Public Member Functions

 QgsProcessingParameterExpression (const QString &name, const QString &description=QString(), const QVariant &defaultValue=QVariant(), const QString &parentLayerParameterName=QString(), bool optional=false)
 Constructor for QgsProcessingParameterExpression. More...
 
QString asPythonString (QgsProcessing::PythonOutputType outputType=QgsProcessing::PythonQgsProcessingAlgorithmSubclass) const override
 Returns the parameter definition as a Python command which can be used within a Python Processing script. More...
 
QgsProcessingParameterDefinitionclone () const override
 Creates a clone of the parameter definition. More...
 
QStringList dependsOnOtherParameters () const override
 Returns a list of other parameter names on which this parameter is dependent (e.g. More...
 
bool fromVariantMap (const QVariantMap &map) override
 Restores this parameter to a QVariantMap. More...
 
QString parentLayerParameterName () const
 Returns the name of the parent layer parameter, or an empty string if this is not set. More...
 
void setParentLayerParameterName (const QString &parentLayerParameterName)
 Sets the name of the parent layer parameter. More...
 
QVariantMap toVariantMap () const override
 Saves this parameter to a QVariantMap. More...
 
QString type () const override
 Unique parameter type name. More...
 
QString valueAsPythonString (const QVariant &value, QgsProcessingContext &context) const override
 Returns a string version of the parameter input value, which is suitable for use as an input parameter value when running an algorithm directly from a Python command. More...
 
- Public Member Functions inherited from QgsProcessingParameterDefinition
 QgsProcessingParameterDefinition (const QString &name, const QString &description=QString(), const QVariant &defaultValue=QVariant(), bool optional=false)
 Constructor for QgsProcessingParameterDefinition. More...
 
virtual ~QgsProcessingParameterDefinition ()=default
 
QStringList additionalExpressionContextVariables () const
 Returns a list of additional expression context variables which are available for use when evaluating this parameter. More...
 
QgsProcessingAlgorithmalgorithm () const
 Returns a pointer to the algorithm which owns this parameter. More...
 
virtual QString asScriptCode () const
 Returns the parameter definition encoded in a string which can be used within a Processing script. More...
 
virtual bool checkValueIsAcceptable (const QVariant &input, QgsProcessingContext *context=nullptr) const
 Checks whether the specified input value is acceptable for the parameter. More...
 
QVariant defaultValue () const
 Returns the default value for the parameter. More...
 
QString description () const
 Returns the description for the parameter. More...
 
QString dynamicLayerParameterName () const
 Returns the name of the parameter for a layer linked to a dynamic parameter, or an empty string if this is not set. More...
 
QgsPropertyDefinition dynamicPropertyDefinition () const
 Returns the property definition for dynamic properties. More...
 
Flags flags () const
 Returns any flags associated with the parameter. More...
 
virtual bool isDestination () const
 Returns true if this parameter represents a file or layer destination, e.g. More...
 
bool isDynamic () const
 Returns true if the parameter supports is dynamic, and can support data-defined values (i.e. More...
 
QVariantMap metadata () const
 Returns the parameter's freeform metadata. More...
 
QVariantMap & metadata ()
 Returns the parameter's freeform metadata. More...
 
QString name () const
 Returns the name of the parameter. More...
 
QgsProcessingProviderprovider () const
 Returns a pointer to the provider for the algorithm which owns this parameter. More...
 
void setAdditionalExpressionContextVariables (const QStringList &variables)
 Sets a list of additional expression context variables which are available for use when evaluating this parameter. More...
 
void setDefaultValue (const QVariant &value)
 Sets the default value for the parameter. More...
 
void setDescription (const QString &description)
 Sets the description for the parameter. More...
 
void setDynamicLayerParameterName (const QString &name)
 Sets the name for the parameter for a layer linked to a dynamic parameter, or an empty string if this is not set. More...
 
void setDynamicPropertyDefinition (const QgsPropertyDefinition &definition)
 Sets the property definition for dynamic properties. More...
 
void setFlags (Flags flags)
 Sets the flags associated with the parameter. More...
 
void setIsDynamic (bool dynamic)
 Sets whether the parameter is dynamic, and can support data-defined values (i.e. More...
 
void setMetadata (const QVariantMap &metadata)
 Sets the parameter's freeform metadata. More...
 
void setName (const QString &name)
 Sets the name of the parameter. More...
 
virtual QString toolTip () const
 Returns a formatted tooltip for use with the parameter, which gives helpful information like parameter description, ID, and extra content like default values (depending on parameter type). More...
 

Static Public Member Functions

static QgsProcessingParameterExpressionfromScriptCode (const QString &name, const QString &description, bool isOptional, const QString &definition)
 Creates a new parameter using the definition from a script code. More...
 
static QString typeName ()
 Returns the type name for the parameter class. More...
 

Additional Inherited Members

- Public Types inherited from QgsProcessingParameterDefinition
enum  Flag { FlagAdvanced = 1 << 1, FlagHidden = 1 << 2, FlagOptional = 1 << 3, FlagIsModelOutput = 1 << 4 }
 Parameter flags. More...
 
- Protected Attributes inherited from QgsProcessingParameterDefinition
QStringList mAdditionalExpressionVariables
 Additional expression context variables exposed for use by this parameter. More...
 
QgsProcessingAlgorithmmAlgorithm = nullptr
 Pointer to algorithm which owns this parameter. More...
 
QVariant mDefault
 Default value for parameter. More...
 
QString mDescription
 Parameter description. More...
 
QString mDynamicLayerParameterName
 Linked vector layer parameter name for dynamic properties. More...
 
Flags mFlags
 Parameter flags. More...
 
bool mIsDynamic = false
 True for dynamic parameters, which can have data-defined (QgsProperty) based values. More...
 
QVariantMap mMetadata
 Freeform metadata for parameter. Mostly used by widget wrappers to customize their appearance and behavior. More...
 
QString mName
 Parameter name. More...
 
QgsPropertyDefinition mPropertyDefinition
 Data defined property definition. More...
 

Detailed Description

An expression parameter for processing algorithms.

Since
QGIS 3.0

Definition at line 2080 of file qgsprocessingparameters.h.

Constructor & Destructor Documentation

◆ QgsProcessingParameterExpression()

QgsProcessingParameterExpression::QgsProcessingParameterExpression ( const QString &  name,
const QString &  description = QString(),
const QVariant &  defaultValue = QVariant(),
const QString &  parentLayerParameterName = QString(),
bool  optional = false 
)

Constructor for QgsProcessingParameterExpression.

Definition at line 3588 of file qgsprocessingparameters.cpp.

Member Function Documentation

◆ asPythonString()

QString QgsProcessingParameterExpression::asPythonString ( QgsProcessing::PythonOutputType  outputType = QgsProcessing::PythonQgsProcessingAlgorithmSubclass) const
overridevirtual

Returns the parameter definition as a Python command which can be used within a Python Processing script.

The outputType argument specifies the desired output format for the Python string, i.e. the intended end use of the generated Python code.

Since
QGIS 3.6

Reimplemented from QgsProcessingParameterDefinition.

Definition at line 3620 of file qgsprocessingparameters.cpp.

◆ clone()

QgsProcessingParameterDefinition * QgsProcessingParameterExpression::clone ( ) const
overridevirtual

Creates a clone of the parameter definition.

Implements QgsProcessingParameterDefinition.

Definition at line 3595 of file qgsprocessingparameters.cpp.

◆ dependsOnOtherParameters()

QStringList QgsProcessingParameterExpression::dependsOnOtherParameters ( ) const
overridevirtual

Returns a list of other parameter names on which this parameter is dependent (e.g.

field parameters which depend on a parent layer parameter).

Reimplemented from QgsProcessingParameterDefinition.

Definition at line 3612 of file qgsprocessingparameters.cpp.

◆ fromScriptCode()

QgsProcessingParameterExpression * QgsProcessingParameterExpression::fromScriptCode ( const QString &  name,
const QString &  description,
bool  isOptional,
const QString &  definition 
)
static

Creates a new parameter using the definition from a script code.

Definition at line 3664 of file qgsprocessingparameters.cpp.

◆ fromVariantMap()

bool QgsProcessingParameterExpression::fromVariantMap ( const QVariantMap &  map)
overridevirtual

Restores this parameter to a QVariantMap.

Subclasses should ensure that they call the base class method.

See also
toVariantMap()

Reimplemented from QgsProcessingParameterDefinition.

Definition at line 3657 of file qgsprocessingparameters.cpp.

◆ parentLayerParameterName()

QString QgsProcessingParameterExpression::parentLayerParameterName ( ) const

Returns the name of the parent layer parameter, or an empty string if this is not set.

See also
setParentLayerParameterName()

Definition at line 3640 of file qgsprocessingparameters.cpp.

◆ setParentLayerParameterName()

void QgsProcessingParameterExpression::setParentLayerParameterName ( const QString &  parentLayerParameterName)

Sets the name of the parent layer parameter.

Use an empty string if this is not required.

See also
parentLayerParameterName()

Definition at line 3645 of file qgsprocessingparameters.cpp.

◆ toVariantMap()

QVariantMap QgsProcessingParameterExpression::toVariantMap ( ) const
overridevirtual

Saves this parameter to a QVariantMap.

Subclasses should ensure that they call the base class method and then extend the result with additional properties.

See also
fromVariantMap()

Reimplemented from QgsProcessingParameterDefinition.

Definition at line 3650 of file qgsprocessingparameters.cpp.

◆ type()

QString QgsProcessingParameterExpression::type ( ) const
inlineoverridevirtual

Unique parameter type name.

Implements QgsProcessingParameterDefinition.

Definition at line 2096 of file qgsprocessingparameters.h.

◆ typeName()

static QString QgsProcessingParameterExpression::typeName ( )
inlinestatic

Returns the type name for the parameter class.

Definition at line 2094 of file qgsprocessingparameters.h.

◆ valueAsPythonString()

QString QgsProcessingParameterExpression::valueAsPythonString ( const QVariant &  value,
QgsProcessingContext context 
) const
overridevirtual

Returns a string version of the parameter input value, which is suitable for use as an input parameter value when running an algorithm directly from a Python command.

Reimplemented from QgsProcessingParameterDefinition.

Definition at line 3600 of file qgsprocessingparameters.cpp.


The documentation for this class was generated from the following files: