QgsValueRelationFieldFormatter Class Reference

Field formatter for a value relation field. More...

#include <qgsvaluerelationfieldformatter.h>

Inheritance diagram for QgsValueRelationFieldFormatter:

Classes
struct	ValueRelationItem

Public Types
typedef QVector< QgsValueRelationFieldFormatter::ValueRelationItem >	ValueRelationCache

Public Member Functions
	QgsValueRelationFieldFormatter ()=default
	Constructor for QgsValueRelationFieldFormatter. More...
QVariant	createCache (QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config) const override
	Create a cache for a given field. More...
QString	id () const override
	Return a unique id for this field formatter. More...
QString	representValue (QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value) const override
	Create a pretty String representation of the value. More...
QVariant	sortValue (QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value) const override
	If the default sort order should be overwritten for this widget, you can transform the value in here. More...
Public Member Functions inherited from QgsFieldFormatter
	QgsFieldFormatter ()
virtual	~QgsFieldFormatter ()=default
virtual Qt::AlignmentFlag	alignmentFlag (QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config) const
	Return the alignment for a particular field. More...

Static Public Member Functions
static QgsValueRelationFieldFormatter::ValueRelationCache	createCache (const QVariantMap &config)
	Create a cache for a value relation field. More...

Detailed Description

Field formatter for a value relation field.

A value relation field formatter looks up the values from features on another layer.

Since

QGIS 3.0

Definition at line 33 of file qgsvaluerelationfieldformatter.h.

Member Typedef Documentation

ValueRelationCache

typedef QVector< QgsValueRelationFieldFormatter::ValueRelationItem > QgsValueRelationFieldFormatter::ValueRelationCache

Definition at line 51 of file qgsvaluerelationfieldformatter.h.

Constructor & Destructor Documentation

QgsValueRelationFieldFormatter()

QgsValueRelationFieldFormatter::QgsValueRelationFieldFormatter ( )

default

Constructor for QgsValueRelationFieldFormatter.

Member Function Documentation

createCache() [1/2]

QVariant QgsValueRelationFieldFormatter::createCache ( QgsVectorLayer *  layer, int  fieldIndex, const QVariantMap &  config  ) const

overridevirtual

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.

Since

QGIS 3.0

Reimplemented from QgsFieldFormatter.

Definition at line 94 of file qgsvaluerelationfieldformatter.cpp.

createCache() [2/2]

QgsValueRelationFieldFormatter::ValueRelationCache QgsValueRelationFieldFormatter::createCache ( const QVariantMap &  config )

static

Create a cache for a value relation field.

This can be used to keep the value map in the local memory if doing multiple lookups in a loop.

Since

QGIS 3.0

Definition at line 102 of file qgsvaluerelationfieldformatter.cpp.

id()

QString QgsValueRelationFieldFormatter::id ( ) const

overridevirtual

Return 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.

Implements QgsFieldFormatter.

Definition at line 34 of file qgsvaluerelationfieldformatter.cpp.

representValue()

QString QgsValueRelationFieldFormatter::representValue ( QgsVectorLayer *  layer, int  fieldIndex, const QVariantMap &  config, const QVariant &  cache, const QVariant &  value  ) const

overridevirtual

Create a pretty String representation of the value.

Returns

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

Since

QGIS 3.0

Reimplemented from QgsFieldFormatter.

Definition at line 39 of file qgsvaluerelationfieldformatter.cpp.

sortValue()

QVariant QgsValueRelationFieldFormatter::sortValue ( QgsVectorLayer *  layer, int  fieldIndex, const QVariantMap &  config, const QVariant &  cache, const QVariant &  value  ) const

overridevirtual

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

Returns

an unmodified value by default.

Since

QGIS 3.0

Reimplemented from QgsFieldFormatter.

Definition at line 89 of file qgsvaluerelationfieldformatter.cpp.

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

• /tmp/buildd/qgis-3.0.2+14stretch/src/core/fieldformatter/qgsvaluerelationfieldformatter.h
• /tmp/buildd/qgis-3.0.2+14stretch/src/core/fieldformatter/qgsvaluerelationfieldformatter.cpp