QGIS API Documentation  3.21.0-Master (5b68dc587e)
Public Member Functions | Static Public Member Functions | List of all members
QgsProcessingParameterString Class Reference

A string parameter for processing algorithms. More...

#include <qgsprocessingparameters.h>

Inheritance diagram for QgsProcessingParameterString:
Inheritance graph
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Public Member Functions

 QgsProcessingParameterString (const QString &name, const QString &description=QString(), const QVariant &defaultValue=QVariant(), bool multiLine=false, bool optional=false)
 Constructor for QgsProcessingParameterString. 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...
 
QString asScriptCode () const override
 Returns the parameter definition encoded in a string which can be used within a Processing script. More...
 
QgsProcessingParameterDefinitionclone () const override
 Creates a clone of the parameter definition. More...
 
bool fromVariantMap (const QVariantMap &map) override
 Restores this parameter to a QVariantMap. More...
 
bool multiLine () const
 Returns true if the parameter allows multiline strings. More...
 
void setMultiLine (bool multiLine)
 Sets whether the parameter allows multiline strings. 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, const QString &help=QString())
 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 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...
 
QVariant defaultValueForGui () const
 Returns the default value to use for the parameter in a GUI. More...
 
virtual QStringList dependsOnOtherParameters () const
 Returns a list of other parameter names on which this parameter is dependent (e.g. 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...
 
QVariant guiDefaultValueOverride () const
 Returns the default value to use in the GUI for the parameter. More...
 
QString help () const
 Returns the help for 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 ()
 Returns the parameter's freeform metadata. More...
 
QVariantMap metadata () const
 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 setGuiDefaultValueOverride (const QVariant &value)
 Sets the default value to use for the parameter in GUI widgets. More...
 
void setHelp (const QString &help)
 Sets the help for 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...
 
virtual QString valueAsPythonComment (const QVariant &value, QgsProcessingContext &context) const
 Returns a Python comment explaining a parameter value, or an empty string if no comment is required. More...
 

Static Public Member Functions

static QgsProcessingParameterStringfromScriptCode (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...
 
QVariant mGuiDefault
 Default value for parameter in GUI. More...
 
QString mHelp
 Parameter help. 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

A string parameter for processing algorithms.

A parameter type which allows users to enter any string value.

In some circumstances it is desirable to restrict the values available when a user is asked to enter a string parameter to a list of predetermined "valid" values. Since QGIS 3.22 this can be done by setting the widget wrapper metadata "value_hints" option, as demonstrated below. (While this provides a mechanism for guiding users to select from valid string values when running a Processing algorithm through the GUI, it does not place any limits on the string values accepted via PyQGIS codes or when running the algorithm via other non-gui means. Algorithms should gracefully handle other values accordingly.)

param = QgsProcessingParameterString( 'PRINTER_NAME', 'Printer name')
# show only printers which are available on the current system as options
# for the string input.
param.setMetadata( {'widget_wrapper':
{ 'value_hints': ['Inkjet printer', 'Laser printer'] }
})
A string parameter for processing algorithms.
Since
QGIS 3.0

Definition at line 2587 of file qgsprocessingparameters.h.

Constructor & Destructor Documentation

◆ QgsProcessingParameterString()

QgsProcessingParameterString::QgsProcessingParameterString ( const QString &  name,
const QString &  description = QString(),
const QVariant &  defaultValue = QVariant(),
bool  multiLine = false,
bool  optional = false 
)

Constructor for QgsProcessingParameterString.

Definition at line 4700 of file qgsprocessingparameters.cpp.

Member Function Documentation

◆ asPythonString()

QString QgsProcessingParameterString::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 4738 of file qgsprocessingparameters.cpp.

◆ asScriptCode()

QString QgsProcessingParameterString::asScriptCode ( ) const
overridevirtual

Returns the parameter definition encoded in a string which can be used within a Processing script.

Reimplemented from QgsProcessingParameterDefinition.

Definition at line 4724 of file qgsprocessingparameters.cpp.

◆ clone()

QgsProcessingParameterDefinition * QgsProcessingParameterString::clone ( ) const
overridevirtual

Creates a clone of the parameter definition.

Implements QgsProcessingParameterDefinition.

Definition at line 4707 of file qgsprocessingparameters.cpp.

◆ fromScriptCode()

QgsProcessingParameterString * QgsProcessingParameterString::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 4782 of file qgsprocessingparameters.cpp.

◆ fromVariantMap()

bool QgsProcessingParameterString::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 4775 of file qgsprocessingparameters.cpp.

◆ multiLine()

bool QgsProcessingParameterString::multiLine ( ) const

Returns true if the parameter allows multiline strings.

See also
setMultiLine()

Definition at line 4758 of file qgsprocessingparameters.cpp.

◆ setMultiLine()

void QgsProcessingParameterString::setMultiLine ( bool  multiLine)

Sets whether the parameter allows multiline strings.

See also
multiLine()

Definition at line 4763 of file qgsprocessingparameters.cpp.

◆ toVariantMap()

QVariantMap QgsProcessingParameterString::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 4768 of file qgsprocessingparameters.cpp.

◆ type()

QString QgsProcessingParameterString::type ( ) const
inlineoverridevirtual

Unique parameter type name.

Implements QgsProcessingParameterDefinition.

Definition at line 2603 of file qgsprocessingparameters.h.

◆ typeName()

static QString QgsProcessingParameterString::typeName ( )
inlinestatic

Returns the type name for the parameter class.

Definition at line 2601 of file qgsprocessingparameters.h.

◆ valueAsPythonString()

QString QgsProcessingParameterString::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 4712 of file qgsprocessingparameters.cpp.


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