Class: QgsFieldFormatter

A field formatter helps to handle and display values for a field.

It allows for using a shared configuration with the editor widgets for representation of attribute values. Field kits normally have one single instance which is managed by the QgsFieldFormatterRegistry. Custom field formatters should be registered there and field formatters for use within code should normally be obtained from there.

This is an abstract base class and will always need to be subclassed.

Note

This is an abstract class, with methods which must be implemented by a subclass.

The following methods must be implemented: id()

Class Hierarchy

Subclasses

QgsCheckBoxFieldFormatter	Field formatter for a checkbox field.
QgsDateTimeFieldFormatter	Field formatter for a date time field.
QgsFallbackFieldFormatter	A default fallback field formatter in case no specialized field formatter is defined.
QgsKeyValueFieldFormatter	Field formatter for a key value field.
QgsListFieldFormatter	Field formatter for a list field.
QgsRangeFieldFormatter	Field formatter for a range (double) field with precision and locale.
QgsRelationReferenceFieldFormatter	Field formatter for a relation reference field.
QgsValueMapFieldFormatter	Field formatter for a ValueMap field.
QgsValueRelationFieldFormatter	Field formatter for a value relation field.

Abstract Methods

id	Returns a unique id for this field formatter.

Methods

flags	Returns the flags
setFlags	Sets the flags

Virtual Methods

In PyQGIS, only methods marked as virtual can be safely overridden in a Python subclass of QgsFieldFormatter. See the FAQ for more details.

alignmentFlag	Returns the alignment for a particular field.
availableValues	Returns a list of the values that would be possible to select with this widget type On a RelationReference that would be the parents ids or on ValueMap all the configured keys according to the settings in the config
createCache	Create a cache for a given field.
representValue	Create a pretty String representation of the value.
sortValue	If the default sort order should be overwritten for this widget, you can transform the value in here.

Attributes

CanProvideAvailableValues

class qgis.core.QgsFieldFormatter

Bases: object

CanProvideAvailableValues = 1

class Flag

Bases: int

class Flags

class Flags(f: QgsFieldFormatter.Flags | QgsFieldFormatter.Flag)

class Flags(a0: QgsFieldFormatter.Flags)

Bases: object

virtual alignmentFlag(self, layer: QgsVectorLayer | None, fieldIndex: int, config: Dict[str, Any]) → Qt.AlignmentFlag

Returns the alignment for a particular field. By default this will consider the field type but can be overwritten if mapped values are represented.

Parameters:

• layer (Optional[QgsVectorLayer])

• fieldIndex (int)

• config (Dict[str, Any])

Return type:

Qt.AlignmentFlag

virtual availableValues(self, config: Dict[str, Any], countLimit: int, context: QgsFieldFormatterContext) → List[Any]

Returns a list of the values that would be possible to select with this widget type On a RelationReference that would be the parents ids or on ValueMap all the configured keys according to the settings in the config

Added in version 3.12.

Parameters:

• config (Dict[str, Any])

• countLimit (int)

• context (QgsFieldFormatterContext)

Return type:

List[Any]

virtual createCache(self, layer: QgsVectorLayer | None, fieldIndex: int, config: Dict[str, Any]) → Any

Create a cache for a given field.

This will be used in situations where a field is being represented various times in a loop. And will be passed to other methods on QgsFieldKit and QgsEditorWidgetWrapper.

For example, the attribute table will create a cache once for each field and then use this cache for representation. The QgsValueRelationFieldFormatter and QgsValueRelationEditorWidget implement this functionality to create a lookuptable once (a QVariantMap / dict) and are make use of a cache if present.

Parameters:

• layer (Optional[QgsVectorLayer])

• fieldIndex (int)

• config (Dict[str, Any])

Return type:

Any

flags(self) → QgsFieldFormatter.Flags

Returns the flags

Added in version 3.12.

Return type:

QgsFieldFormatter.Flags

abstract id(self) → str

Returns a unique id for this field formatter. This id will later be used to identify this field formatter in the registry with QgsFieldFormatterRegistry.fieldFormatter().

This id matches the id of a QgsEditorWidgetFactory.

Return type:

str

virtual representValue(self, layer: QgsVectorLayer | None, fieldIndex: int, config: Dict[str, Any], cache: Any, value: Any) → str

Create a pretty String representation of the value.

Return type:

str

Returns:

By default the string representation of the provided value as implied by the field definition is returned.

Parameters:

• layer (Optional[QgsVectorLayer])

• fieldIndex (int)

• config (Dict[str, Any])

• cache (Any)

• value (Any)

setFlags(self, flags: QgsFieldFormatter.Flags | QgsFieldFormatter.Flag)

Sets the flags

Added in version 3.12.

Parameters:

flags (Union[QgsFieldFormatter.Flags, QgsFieldFormatter.Flag])

virtual sortValue(self, layer: QgsVectorLayer | None, fieldIndex: int, config: Dict[str, Any], cache: Any, value: Any) → Any

If the default sort order should be overwritten for this widget, you can transform the value in here.

Return type:

Any

Returns:

an unmodified value by default.

Parameters:

• layer (Optional[QgsVectorLayer])

• fieldIndex (int)

• config (Dict[str, Any])

• cache (Any)

• value (Any)