Defines left outer join from our vector layer to some other vector layer. More...

#include <qgsvectorlayerjoininfo.h>

Public Member Functions
	QgsVectorLayerJoinInfo ()=default
	Constructor for QgsVectorLayerJoinInfo.

QgsFeature	extractJoinedFeature (const QgsFeature &feature) const
	Extract the join feature from the target feature for the current join layer information.

bool	hasCascadedDelete () const
	Returns whether a feature deleted on the target layer has to impact the joined layer by deleting the corresponding joined feature.

bool	hasSubset (bool blocklisted=true) const
	Returns `true` if blocklisted fields is not empty or if a subset of names has been set.

bool	hasUpsertOnEdit () const
	Returns whether a feature created on the target layer has to impact the joined layer by creating a new feature if necessary.

bool	isDynamicFormEnabled () const
	Returns whether the form has to be dynamically updated with joined fields when a feature is being created in the target layer.

bool	isEditable () const
	Returns whether joined fields may be edited through the form of the target layer.

bool	isUsingMemoryCache () const
	Returns whether values from the joined layer should be cached in memory to speed up lookups.

QString	joinFieldName () const
	Returns name of the field of joined layer that will be used for join.

Q_DECL_DEPRECATED QStringList	joinFieldNamesBlackList () const
	Returns the list of fields to ignore.

QStringList	joinFieldNamesBlockList () const
	Returns the list of fields to ignore.

QStringList *	joinFieldNamesSubset () const
	Returns the subset of fields to be used from joined layer.

QgsVectorLayer *	joinLayer () const
	Returns joined layer (may be `nullptr` if the reference was set by layer ID and not resolved yet)

QString	joinLayerId () const
	ID of the joined layer - may be used to resolve reference to the joined layer.

bool	operator== (const QgsVectorLayerJoinInfo &other) const

QString	prefix () const
	Returns prefix of fields from the joined layer. If `nullptr`, joined layer's name will be used.

QString	prefixedFieldName (const QgsField &field) const
	Returns the prefixed name of the field.

void	setCascadedDelete (bool enabled)
	Sets whether a feature deleted on the target layer has to impact the joined layer by deleting the corresponding joined feature.

void	setDynamicFormEnabled (bool enabled)
	Sets whether the form has to be dynamically updated with joined fields when a feature is being created in the target layer.

void	setEditable (bool enabled)
	Sets whether the form of the target layer allows editing joined fields.

void	setJoinFieldName (const QString &fieldName)
	Sets name of the field of joined layer that will be used for join.

Q_DECL_DEPRECATED void	setJoinFieldNamesBlackList (const QStringList &blackList)
	Sets a list of fields to ignore whatever happens.

void	setJoinFieldNamesBlockList (const QStringList &list)
	Sets a list of fields to ignore whatever happens.

void	setJoinFieldNamesSubset (QStringList *fieldNamesSubset)
	Sets the subset of fields to be used from joined layer.

void	setJoinLayer (QgsVectorLayer *layer)
	Sets weak reference to the joined layer.

void	setJoinLayerId (const QString &layerId)
	Sets ID of the joined layer. It will need to be overwritten by setJoinLayer() to a reference to real layer.

void	setPrefix (const QString &prefix)
	Sets prefix of fields from the joined layer. If `nullptr`, joined layer's name will be used.

void	setTargetFieldName (const QString &fieldName)
	Sets name of the field of our layer that will be used for join.

void	setUpsertOnEdit (bool enabled)
	Sets whether a feature created on the target layer has to impact the joined layer by creating a new feature if necessary.

void	setUsingMemoryCache (bool enabled)
	Sets whether values from the joined layer should be cached in memory to speed up lookups.

QString	targetFieldName () const
	Returns name of the field of our layer that will be used for join.

Static Public Member Functions
static QStringList	joinFieldNamesSubset (const QgsVectorLayerJoinInfo &info, bool blocklisted=true)
	Returns the list of field names to use for joining considering blocklisted fields and subset.

static QStringList	joinFieldNamesSubset (const QgsVectorLayerJoinInfo &info, const QgsFields &joinLayerFields, bool blocklisted=true)
	Returns the list of field names to use for joining considering blocklisted fields and subset.

Protected Attributes
QHash< QString, QgsAttributes >	cachedAttributes
	Cache for joined attributes to provide fast lookup (size is 0 if no memory caching)

bool	cacheDirty = true
	True if the cached join attributes need to be updated.

QStringList	mBlockList

bool	mCascadedDelete = false

bool	mDynamicForm = false

bool	mEditable = false

QString	mJoinFieldName
	Join field in the source layer.

std::shared_ptr< QStringList >	mJoinFieldsSubset
	Subset of fields to use from joined layer. `nullptr` = use all fields.

QgsVectorLayerRef	mJoinLayerRef
	Weak reference to the joined layer.

bool	mMemoryCache = false
	True if the join is cached in virtual memory.

QString	mPrefix
	An optional prefix.

QString	mTargetFieldName
	Join field in the target layer.

bool	mUpsertOnEdit = false

Friends
class	QgsVectorLayerFeatureIterator

class	QgsVectorLayerJoinBuffer

Detailed Description

Defines left outer join from our vector layer to some other vector layer.

The join is done based on [our layer].targetField = [join layer].joinField

Definition at line 32 of file qgsvectorlayerjoininfo.h.

Constructor & Destructor Documentation

◆ QgsVectorLayerJoinInfo()

QgsVectorLayerJoinInfo::QgsVectorLayerJoinInfo ( )

default

Constructor for QgsVectorLayerJoinInfo.

Member Function Documentation

◆ extractJoinedFeature()

QgsFeature QgsVectorLayerJoinInfo::extractJoinedFeature ( const QgsFeature & feature ) const

Extract the join feature from the target feature for the current join layer information.

Parameters

feature A feature from the target layer

Returns: the corresponding joined feature

Definition at line 62 of file qgsvectorlayerjoininfo.cpp.

◆ hasCascadedDelete()

bool QgsVectorLayerJoinInfo::hasCascadedDelete ( ) const

inline

Returns whether a feature deleted on the target layer has to impact the joined layer by deleting the corresponding joined feature.

Definition at line 114 of file qgsvectorlayerjoininfo.h.

◆ hasSubset()

bool QgsVectorLayerJoinInfo::hasSubset ( bool blocklisted = true ) const

Returns true if blocklisted fields is not empty or if a subset of names has been set.

Definition at line 128 of file qgsvectorlayerjoininfo.cpp.

◆ hasUpsertOnEdit()

bool QgsVectorLayerJoinInfo::hasUpsertOnEdit ( ) const

inline

Returns whether a feature created on the target layer has to impact the joined layer by creating a new feature if necessary.

Definition at line 102 of file qgsvectorlayerjoininfo.h.

◆ isDynamicFormEnabled()

bool QgsVectorLayerJoinInfo::isDynamicFormEnabled ( ) const

inline

Returns whether the form has to be dynamically updated with joined fields when a feature is being created in the target layer.

Definition at line 79 of file qgsvectorlayerjoininfo.h.

◆ isEditable()

bool QgsVectorLayerJoinInfo::isEditable ( ) const

inline

Returns whether joined fields may be edited through the form of the target layer.

Definition at line 91 of file qgsvectorlayerjoininfo.h.

◆ isUsingMemoryCache()

bool QgsVectorLayerJoinInfo::isUsingMemoryCache ( ) const

Returns whether values from the joined layer should be cached in memory to speed up lookups.

Will return false if upsertOnEdit is enabled.

Definition at line 43 of file qgsvectorlayerjoininfo.cpp.

◆ joinFieldName()

QString QgsVectorLayerJoinInfo::joinFieldName ( ) const

inline

Returns name of the field of joined layer that will be used for join.

Definition at line 59 of file qgsvectorlayerjoininfo.h.

◆ joinFieldNamesBlackList()

Q_DECL_DEPRECATED QStringList QgsVectorLayerJoinInfo::joinFieldNamesBlackList ( ) const

inline

Returns the list of fields to ignore.

Deprecated:: use joinFieldNamesBlockList() instead

Definition at line 149 of file qgsvectorlayerjoininfo.h.

◆ joinFieldNamesBlockList()

QStringList QgsVectorLayerJoinInfo::joinFieldNamesBlockList ( ) const

inline

Returns the list of fields to ignore.

See also: setJoinFieldNamesBlockList()

Since: QGIS 3.14

Definition at line 165 of file qgsvectorlayerjoininfo.h.

◆ joinFieldNamesSubset() [1/3]

QStringList * QgsVectorLayerJoinInfo::joinFieldNamesSubset ( ) const

inline

Returns the subset of fields to be used from joined layer.

All fields will be used if nullptr is returned.

See also: setJoinFieldNamesSubset()

Definition at line 221 of file qgsvectorlayerjoininfo.h.

◆ joinFieldNamesSubset() [2/3]

QStringList QgsVectorLayerJoinInfo::joinFieldNamesSubset	(	const QgsVectorLayerJoinInfo &	info,
		bool	blocklisted = `true`
	)

static

Returns the list of field names to use for joining considering blocklisted fields and subset.

Warning: This method is NOT thread safe, and MUST be called from the thread where the vector layers participating in the join reside. See variant which accepts a QgsFields argument for a thread safe alternative.

Definition at line 86 of file qgsvectorlayerjoininfo.cpp.

◆ joinFieldNamesSubset() [3/3]

QStringList QgsVectorLayerJoinInfo::joinFieldNamesSubset	(	const QgsVectorLayerJoinInfo &	info,
		const QgsFields &	joinLayerFields,
		bool	blocklisted = `true`
	)

static

Returns the list of field names to use for joining considering blocklisted fields and subset.

This method is thread safe.

Since: QGIS 3.30

Definition at line 91 of file qgsvectorlayerjoininfo.cpp.

◆ joinLayer()

QgsVectorLayer * QgsVectorLayerJoinInfo::joinLayer ( ) const

inline

Returns joined layer (may be nullptr if the reference was set by layer ID and not resolved yet)

Definition at line 44 of file qgsvectorlayerjoininfo.h.

◆ joinLayerId()

QString QgsVectorLayerJoinInfo::joinLayerId ( ) const

inline

ID of the joined layer - may be used to resolve reference to the joined layer.

Definition at line 49 of file qgsvectorlayerjoininfo.h.

◆ operator==()

bool QgsVectorLayerJoinInfo::operator== ( const QgsVectorLayerJoinInfo & other ) const

inline

Definition at line 194 of file qgsvectorlayerjoininfo.h.

◆ prefix()

QString QgsVectorLayerJoinInfo::prefix ( ) const

inline

Returns prefix of fields from the joined layer. If nullptr, joined layer's name will be used.

Definition at line 64 of file qgsvectorlayerjoininfo.h.

◆ prefixedFieldName()

QString QgsVectorLayerJoinInfo::prefixedFieldName ( const QgsField & field ) const

Returns the prefixed name of the field.

Parameters

field the field

Returns: the prefixed name of the field

Definition at line 21 of file qgsvectorlayerjoininfo.cpp.

◆ setCascadedDelete()

void QgsVectorLayerJoinInfo::setCascadedDelete ( bool enabled )

inline

Sets whether a feature deleted on the target layer has to impact the joined layer by deleting the corresponding joined feature.

Definition at line 120 of file qgsvectorlayerjoininfo.h.

◆ setDynamicFormEnabled()

void QgsVectorLayerJoinInfo::setDynamicFormEnabled ( bool enabled )

inline

Sets whether the form has to be dynamically updated with joined fields when a feature is being created in the target layer.

Definition at line 85 of file qgsvectorlayerjoininfo.h.

◆ setEditable()

void QgsVectorLayerJoinInfo::setEditable ( bool enabled )

Sets whether the form of the target layer allows editing joined fields.

Definition at line 51 of file qgsvectorlayerjoininfo.cpp.

◆ setJoinFieldName()

void QgsVectorLayerJoinInfo::setJoinFieldName ( const QString & fieldName )

inline

Sets name of the field of joined layer that will be used for join.

Definition at line 57 of file qgsvectorlayerjoininfo.h.

◆ setJoinFieldNamesBlackList()

Q_DECL_DEPRECATED void QgsVectorLayerJoinInfo::setJoinFieldNamesBlackList ( const QStringList & blackList )

inline

Sets a list of fields to ignore whatever happens.

Deprecated:: use setJoinFieldNamesBlockList() instead

Definition at line 142 of file qgsvectorlayerjoininfo.h.

◆ setJoinFieldNamesBlockList()

void QgsVectorLayerJoinInfo::setJoinFieldNamesBlockList ( const QStringList & list )

inline

Sets a list of fields to ignore whatever happens.

See also: joinFieldNamesBlockList()

Since: QGIS 3.14

Definition at line 157 of file qgsvectorlayerjoininfo.h.

◆ setJoinFieldNamesSubset()

void QgsVectorLayerJoinInfo::setJoinFieldNamesSubset ( QStringList * fieldNamesSubset )

inline

Sets the subset of fields to be used from joined layer.

Ownership of fileNamesSubset is transferred. A fieldNameSubset of nullptr indicates that all fields should be used.

See also: joinFieldNamesSubset()

Definition at line 211 of file qgsvectorlayerjoininfo.h.

◆ setJoinLayer()

void QgsVectorLayerJoinInfo::setJoinLayer ( QgsVectorLayer * layer )

inline

Sets weak reference to the joined layer.

Definition at line 42 of file qgsvectorlayerjoininfo.h.

◆ setJoinLayerId()

void QgsVectorLayerJoinInfo::setJoinLayerId ( const QString & layerId )

inline

Sets ID of the joined layer. It will need to be overwritten by setJoinLayer() to a reference to real layer.

Definition at line 47 of file qgsvectorlayerjoininfo.h.

◆ setPrefix()

void QgsVectorLayerJoinInfo::setPrefix ( const QString & prefix )

inline

Sets prefix of fields from the joined layer. If nullptr, joined layer's name will be used.

Definition at line 62 of file qgsvectorlayerjoininfo.h.

◆ setTargetFieldName()

void QgsVectorLayerJoinInfo::setTargetFieldName ( const QString & fieldName )

inline

Sets name of the field of our layer that will be used for join.

Definition at line 52 of file qgsvectorlayerjoininfo.h.

◆ setUpsertOnEdit()

void QgsVectorLayerJoinInfo::setUpsertOnEdit ( bool enabled )

inline

Sets whether a feature created on the target layer has to impact the joined layer by creating a new feature if necessary.

Definition at line 108 of file qgsvectorlayerjoininfo.h.

◆ setUsingMemoryCache()

void QgsVectorLayerJoinInfo::setUsingMemoryCache ( bool enabled )

Sets whether values from the joined layer should be cached in memory to speed up lookups.

Definition at line 38 of file qgsvectorlayerjoininfo.cpp.

◆ targetFieldName()

QString QgsVectorLayerJoinInfo::targetFieldName ( ) const

inline

Returns name of the field of our layer that will be used for join.

Definition at line 54 of file qgsvectorlayerjoininfo.h.

Friends And Related Symbol Documentation

◆ QgsVectorLayerFeatureIterator

friend class QgsVectorLayerFeatureIterator

friend

Definition at line 245 of file qgsvectorlayerjoininfo.h.

◆ QgsVectorLayerJoinBuffer

friend class QgsVectorLayerJoinBuffer

friend

Definition at line 244 of file qgsvectorlayerjoininfo.h.

Member Data Documentation

◆ cachedAttributes

QHash< QString, QgsAttributes> QgsVectorLayerJoinInfo::cachedAttributes

protected

Cache for joined attributes to provide fast lookup (size is 0 if no memory caching)

Definition at line 261 of file qgsvectorlayerjoininfo.h.

◆ cacheDirty

bool QgsVectorLayerJoinInfo::cacheDirty = true

protected

True if the cached join attributes need to be updated.

Definition at line 248 of file qgsvectorlayerjoininfo.h.

◆ mBlockList

QStringList QgsVectorLayerJoinInfo::mBlockList

protected

Definition at line 258 of file qgsvectorlayerjoininfo.h.

◆ mCascadedDelete

bool QgsVectorLayerJoinInfo::mCascadedDelete = false

protected

Definition at line 256 of file qgsvectorlayerjoininfo.h.

◆ mDynamicForm

bool QgsVectorLayerJoinInfo::mDynamicForm = false

protected

Definition at line 250 of file qgsvectorlayerjoininfo.h.

◆ mEditable

bool QgsVectorLayerJoinInfo::mEditable = false

protected

Definition at line 252 of file qgsvectorlayerjoininfo.h.

◆ mJoinFieldName

QString QgsVectorLayerJoinInfo::mJoinFieldName

protected

Join field in the source layer.

Definition at line 229 of file qgsvectorlayerjoininfo.h.

◆ mJoinFieldsSubset

std::shared_ptr<QStringList> QgsVectorLayerJoinInfo::mJoinFieldsSubset

protected

Subset of fields to use from joined layer. nullptr = use all fields.

Definition at line 240 of file qgsvectorlayerjoininfo.h.

◆ mJoinLayerRef

QgsVectorLayerRef QgsVectorLayerJoinInfo::mJoinLayerRef

protected

Weak reference to the joined layer.

Definition at line 227 of file qgsvectorlayerjoininfo.h.

◆ mMemoryCache

bool QgsVectorLayerJoinInfo::mMemoryCache = false

protected

True if the join is cached in virtual memory.

Definition at line 237 of file qgsvectorlayerjoininfo.h.

◆ mPrefix

QString QgsVectorLayerJoinInfo::mPrefix

protected

An optional prefix.

If it is a Null string "{layername}_" will be used

Definition at line 234 of file qgsvectorlayerjoininfo.h.

◆ mTargetFieldName

QString QgsVectorLayerJoinInfo::mTargetFieldName

protected

Join field in the target layer.

Definition at line 225 of file qgsvectorlayerjoininfo.h.

◆ mUpsertOnEdit

bool QgsVectorLayerJoinInfo::mUpsertOnEdit = false

protected

Definition at line 254 of file qgsvectorlayerjoininfo.h.

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

/home/fischer/src/qgis-3.38/src/core/vector/qgsvectorlayerjoininfo.h
/home/fischer/src/qgis-3.38/src/core/vector/qgsvectorlayerjoininfo.cpp

Public Member Functions

Static Public Member Functions

Protected Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ QgsVectorLayerJoinInfo()

Member Function Documentation

◆ extractJoinedFeature()

◆ hasCascadedDelete()

◆ hasSubset()

◆ hasUpsertOnEdit()

◆ isDynamicFormEnabled()

◆ isEditable()

◆ isUsingMemoryCache()

◆ joinFieldName()

◆ joinFieldNamesBlackList()

◆ joinFieldNamesBlockList()

◆ joinFieldNamesSubset() [1/3]

◆ joinFieldNamesSubset() [2/3]

◆ joinFieldNamesSubset() [3/3]

◆ joinLayer()

◆ joinLayerId()

◆ operator==()

◆ prefix()

◆ prefixedFieldName()

◆ setCascadedDelete()

◆ setDynamicFormEnabled()

◆ setEditable()

◆ setJoinFieldName()

◆ setJoinFieldNamesBlackList()

◆ setJoinFieldNamesBlockList()

◆ setJoinFieldNamesSubset()

◆ setJoinLayer()

◆ setJoinLayerId()

◆ setPrefix()

◆ setTargetFieldName()

◆ setUpsertOnEdit()

◆ setUsingMemoryCache()

◆ targetFieldName()

Friends And Related Symbol Documentation

◆ QgsVectorLayerFeatureIterator

◆ QgsVectorLayerJoinBuffer

Member Data Documentation

◆ cachedAttributes

◆ cacheDirty

◆ mBlockList

◆ mCascadedDelete

◆ mDynamicForm

◆ mEditable

◆ mJoinFieldName

◆ mJoinFieldsSubset

◆ mJoinLayerRef

◆ mMemoryCache

◆ mPrefix

◆ mTargetFieldName

◆ mUpsertOnEdit