QgsProcessingParameterNumber class

A numeric parameter for processing algorithms.

Reference

For numeric parameters with a dataType() of Double, the number of decimals places shown in the parameter's widget can be specified by setting the parameter's metadata. For example:

param = QgsProcessingParameterNumber( 'VAL', 'Threshold', type=QgsProcessingParameter.Double)
# only show two decimal places in parameter's widgets, not 6:
param.setMetadata( {'widget_wrapper':
  { 'decimals': 2 }
})

Base classes

class QgsProcessingParameterDefinition: Base class for the definition of processing parameters.

Derived classes

class QgsProcessingParameterDistance: A double numeric parameter for distance values.

Public types

enum Type { Integer, Double }: Numeric data type.

Public static functions

static auto fromScriptCode(const QString& name, const QString& description, bool isOptional, const QString& definition) -> QgsProcessingParameterNumber*: Creates a new parameter using the definition from a script code.
static auto typeName() -> QString: Returns the type name for the parameter class.

Constructors, destructors, conversion operators

QgsProcessingParameterNumber(const QString& name, const QString& description = QString(), Type type = Integer, const QVariant& defaultValue = QVariant(), bool optional = false, double minValue = std::numeric_limits<double>::lowest()+1, double maxValue = std::numeric_limits<double>::max()) explicit: Constructor for QgsProcessingParameterNumber.

Public functions

auto checkValueIsAcceptable(const QVariant& input, QgsProcessingContext* context = nullptr) const -> bool override: Checks whether the specified input value is acceptable for the parameter.
auto clone() const -> QgsProcessingParameterDefinition* override: Creates a clone of the parameter definition.
auto dataType() const -> Type: Returns the acceptable data type for the parameter.
auto fromVariantMap(const QVariantMap& map) -> bool override: Restores this parameter to a QVariantMap.
auto maximum() const -> double: Returns the maximum value acceptable by the parameter.
auto minimum() const -> double: Returns the minimum value acceptable by the parameter.
void setDataType(Type type): Sets the acceptable data type for the parameter.
void setMaximum(double maximum): Sets the maximum value acceptable by the parameter.
void setMinimum(double minimum): Sets the minimum value acceptable by the parameter.
auto toolTip() const -> QString override: 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).
auto toVariantMap() const -> QVariantMap override: Saves this parameter to a QVariantMap.
auto type() const -> QString override: Unique parameter type name.
auto valueAsPythonString(const QVariant& value, QgsProcessingContext& context) const -> QString 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.

Enum documentation

enum QgsProcessingParameterNumber::Type

Numeric data type.

Enumerators
Integer	Integer values.
Double	Double/float values.

Function documentation

bool QgsProcessingParameterNumber::checkValueIsAcceptable(const QVariant& input, QgsProcessingContext* context = nullptr) const override

Checks whether the specified input value is acceptable for the parameter.

Returns true if the value can be accepted. The optional context parameter can be specified to allow a more stringent check to be performed, capable of checking for the presence of required layers and other factors within the context.

Type QgsProcessingParameterNumber::dataType() const

Returns the acceptable data type for the parameter.

bool QgsProcessingParameterNumber::fromVariantMap(const QVariantMap& map) override

Restores this parameter to a QVariantMap.

Subclasses should ensure that they call the base class method.

double QgsProcessingParameterNumber::maximum() const

Returns the maximum value acceptable by the parameter.

double QgsProcessingParameterNumber::minimum() const

Returns the minimum value acceptable by the parameter.

void QgsProcessingParameterNumber::setDataType(Type type)

Sets the acceptable data type for the parameter.

void QgsProcessingParameterNumber::setMaximum(double maximum)

Sets the maximum value acceptable by the parameter.

void QgsProcessingParameterNumber::setMinimum(double minimum)

Sets the minimum value acceptable by the parameter.

QVariantMap QgsProcessingParameterNumber::toVariantMap() const override

Saves this parameter to a QVariantMap.

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

QString QgsProcessingParameterNumber::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.

The returned value must be correctly escaped - e.g. string values must be wrapped in ' 's.