QGIS API Documentation  3.3.0-Master (c515a66)
Public Member Functions | Static Public Member Functions | Protected Attributes | Friends | List of all members
QgsVectorLayerJoinInfo Class Reference

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. More...
 
QgsFeature extractJoinedFeature (const QgsFeature &feature) const
 Extract the join feature from the target feature for the current join layer information. More...
 
bool hasCascadedDelete () const
 Returns whether a feature deleted on the target layer has to impact the joined layer by deleting the corresponding joined feature. More...
 
bool hasSubset (bool blacklisted=true) const
 Returns true if blacklisted fields is not empty or if a subset of names has been set. More...
 
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. More...
 
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. More...
 
bool isEditable () const
 Returns whether joined fields may be edited through the form of the target layer. More...
 
bool isUsingMemoryCache () const
 Returns whether values from the joined layer should be cached in memory to speed up lookups. More...
 
QString joinFieldName () const
 Returns name of the field of joined layer that will be used for join. More...
 
QStringList joinFieldNamesBlackList () const
 Returns the list of fields to ignore. More...
 
QStringList * joinFieldNamesSubset () const
 Gets subset of fields to be used from joined layer. More...
 
QgsVectorLayerjoinLayer () const
 Returns joined layer (may be null if the reference was set by layer ID and not resolved yet) More...
 
QString joinLayerId () const
 ID of the joined layer - may be used to resolve reference to the joined layer. More...
 
bool operator== (const QgsVectorLayerJoinInfo &other) const
 
QString prefix () const
 Returns prefix of fields from the joined layer. If null, joined layer's name will be used. More...
 
QString prefixedFieldName (const QgsField &field) const
 Returns the prefixed name of the field. More...
 
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. More...
 
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. More...
 
void setEditable (bool enabled)
 Sets whether the form of the target layer allows editing joined fields. More...
 
void setJoinFieldName (const QString &fieldName)
 Sets name of the field of joined layer that will be used for join. More...
 
void setJoinFieldNamesBlackList (const QStringList &blackList)
 Sets a list of fields to ignore whatever happens. More...
 
void setJoinFieldNamesSubset (QStringList *fieldNamesSubset)
 Set subset of fields to be used from joined layer. More...
 
void setJoinLayer (QgsVectorLayer *layer)
 Sets weak reference to the joined layer. More...
 
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. More...
 
void setPrefix (const QString &prefix)
 Sets prefix of fields from the joined layer. If null, joined layer's name will be used. More...
 
void setTargetFieldName (const QString &fieldName)
 Sets name of the field of our layer that will be used for join. More...
 
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. More...
 
void setUsingMemoryCache (bool enabled)
 Sets whether values from the joined layer should be cached in memory to speed up lookups. More...
 
QString targetFieldName () const
 Returns name of the field of our layer that will be used for join. More...
 

Static Public Member Functions

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

Protected Attributes

QHash< QString, QgsAttributescachedAttributes
 Cache for joined attributes to provide fast lookup (size is 0 if no memory caching) More...
 
bool cacheDirty = true
 True if the cached join attributes need to be updated. More...
 
QStringList mBlackList
 
bool mCascadedDelete = false
 
bool mDynamicForm = false
 
bool mEditable = false
 
QString mJoinFieldName
 Join field in the source layer. More...
 
std::shared_ptr< QStringList > mJoinFieldsSubset
 Subset of fields to use from joined layer. null = use all fields. More...
 
QgsVectorLayerRef mJoinLayerRef
 Weak reference to the joined layer. More...
 
bool mMemoryCache = false
 True if the join is cached in virtual memory. More...
 
QString mPrefix
 An optional prefix. More...
 
QString mTargetFieldName
 Join field in the target layer. More...
 
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

Since
QGIS 3.0

Definition at line 33 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
featureA feature from the target layer
Returns
the corresponding joined feature
Since
QGIS 3.0

Definition at line 48 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.

Since
QGIS 3.0

Definition at line 118 of file qgsvectorlayerjoininfo.h.

◆ hasSubset()

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

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

Since
QGIS 3.0

Definition at line 109 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.

Since
QGIS 3.0

Definition at line 104 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.

Since
QGIS 3.0

Definition at line 77 of file qgsvectorlayerjoininfo.h.

◆ isEditable()

bool QgsVectorLayerJoinInfo::isEditable ( ) const
inline

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

Since
QGIS 3.0

Definition at line 91 of file qgsvectorlayerjoininfo.h.

◆ isUsingMemoryCache()

bool QgsVectorLayerJoinInfo::isUsingMemoryCache ( ) const
inline

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

Definition at line 70 of file qgsvectorlayerjoininfo.h.

◆ joinFieldName()

QString QgsVectorLayerJoinInfo::joinFieldName ( ) const
inline

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

Definition at line 60 of file qgsvectorlayerjoininfo.h.

◆ joinFieldNamesBlackList()

QStringList QgsVectorLayerJoinInfo::joinFieldNamesBlackList ( ) const
inline

Returns the list of fields to ignore.

Since
QGIS 3.0

Definition at line 156 of file qgsvectorlayerjoininfo.h.

◆ joinFieldNamesSubset() [1/2]

QStringList QgsVectorLayerJoinInfo::joinFieldNamesSubset ( const QgsVectorLayerJoinInfo info,
bool  blacklisted = true 
)
static

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

Since
QGIS 3.0

Definition at line 72 of file qgsvectorlayerjoininfo.cpp.

◆ joinFieldNamesSubset() [2/2]

QStringList* QgsVectorLayerJoinInfo::joinFieldNamesSubset ( ) const
inline

Gets subset of fields to be used from joined layer.

All fields will be used if null is returned.

Since
QGIS 2.6

Definition at line 192 of file qgsvectorlayerjoininfo.h.

◆ joinLayer()

QgsVectorLayer* QgsVectorLayerJoinInfo::joinLayer ( ) const
inline

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

Definition at line 45 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 50 of file qgsvectorlayerjoininfo.h.

◆ operator==()

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

Definition at line 174 of file qgsvectorlayerjoininfo.h.

◆ prefix()

QString QgsVectorLayerJoinInfo::prefix ( ) const
inline

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

Definition at line 65 of file qgsvectorlayerjoininfo.h.

◆ prefixedFieldName()

QString QgsVectorLayerJoinInfo::prefixedFieldName ( const QgsField field) const

Returns the prefixed name of the field.

Parameters
fieldthe field
Returns
the prefixed name of the field
Since
QGIS 3.0

Definition at line 20 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.

Since
QGIS 3.0

Definition at line 125 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.

Since
QGIS 3.0

Definition at line 84 of file qgsvectorlayerjoininfo.h.

◆ setEditable()

void QgsVectorLayerJoinInfo::setEditable ( bool  enabled)

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

Since
QGIS 3.0

Definition at line 37 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 58 of file qgsvectorlayerjoininfo.h.

◆ setJoinFieldNamesBlackList()

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

Sets a list of fields to ignore whatever happens.

Since
QGIS 3.0

Definition at line 149 of file qgsvectorlayerjoininfo.h.

◆ setJoinFieldNamesSubset()

void QgsVectorLayerJoinInfo::setJoinFieldNamesSubset ( QStringList *  fieldNamesSubset)
inline

Set subset of fields to be used from joined layer.

Takes ownership of the passed pointer. Null pointer tells to use all fields.

Since
QGIS 2.6

Definition at line 187 of file qgsvectorlayerjoininfo.h.

◆ setJoinLayer()

void QgsVectorLayerJoinInfo::setJoinLayer ( QgsVectorLayer layer)
inline

Sets weak reference to the joined layer.

Definition at line 43 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 48 of file qgsvectorlayerjoininfo.h.

◆ setPrefix()

void QgsVectorLayerJoinInfo::setPrefix ( const QString &  prefix)
inline

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

Definition at line 63 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 53 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.

Since
QGIS 3.0

Definition at line 111 of file qgsvectorlayerjoininfo.h.

◆ setUsingMemoryCache()

void QgsVectorLayerJoinInfo::setUsingMemoryCache ( bool  enabled)
inline

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

Definition at line 68 of file qgsvectorlayerjoininfo.h.

◆ targetFieldName()

QString QgsVectorLayerJoinInfo::targetFieldName ( ) const
inline

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

Definition at line 55 of file qgsvectorlayerjoininfo.h.

Friends And Related Function Documentation

◆ QgsVectorLayerFeatureIterator

friend class QgsVectorLayerFeatureIterator
friend

Definition at line 217 of file qgsvectorlayerjoininfo.h.

◆ QgsVectorLayerJoinBuffer

friend class QgsVectorLayerJoinBuffer
friend

Definition at line 216 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 233 of file qgsvectorlayerjoininfo.h.

◆ cacheDirty

bool QgsVectorLayerJoinInfo::cacheDirty = true
protected

True if the cached join attributes need to be updated.

Definition at line 220 of file qgsvectorlayerjoininfo.h.

◆ mBlackList

QStringList QgsVectorLayerJoinInfo::mBlackList
protected

Definition at line 230 of file qgsvectorlayerjoininfo.h.

◆ mCascadedDelete

bool QgsVectorLayerJoinInfo::mCascadedDelete = false
protected

Definition at line 228 of file qgsvectorlayerjoininfo.h.

◆ mDynamicForm

bool QgsVectorLayerJoinInfo::mDynamicForm = false
protected

Definition at line 222 of file qgsvectorlayerjoininfo.h.

◆ mEditable

bool QgsVectorLayerJoinInfo::mEditable = false
protected

Definition at line 224 of file qgsvectorlayerjoininfo.h.

◆ mJoinFieldName

QString QgsVectorLayerJoinInfo::mJoinFieldName
protected

Join field in the source layer.

Definition at line 200 of file qgsvectorlayerjoininfo.h.

◆ mJoinFieldsSubset

std::shared_ptr<QStringList> QgsVectorLayerJoinInfo::mJoinFieldsSubset
protected

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

Definition at line 212 of file qgsvectorlayerjoininfo.h.

◆ mJoinLayerRef

QgsVectorLayerRef QgsVectorLayerJoinInfo::mJoinLayerRef
protected

Weak reference to the joined layer.

Definition at line 198 of file qgsvectorlayerjoininfo.h.

◆ mMemoryCache

bool QgsVectorLayerJoinInfo::mMemoryCache = false
protected

True if the join is cached in virtual memory.

Definition at line 209 of file qgsvectorlayerjoininfo.h.

◆ mPrefix

QString QgsVectorLayerJoinInfo::mPrefix
protected

An optional prefix.

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

Since
QGIS 2.8

Definition at line 206 of file qgsvectorlayerjoininfo.h.

◆ mTargetFieldName

QString QgsVectorLayerJoinInfo::mTargetFieldName
protected

Join field in the target layer.

Definition at line 196 of file qgsvectorlayerjoininfo.h.

◆ mUpsertOnEdit

bool QgsVectorLayerJoinInfo::mUpsertOnEdit = false
protected

Definition at line 226 of file qgsvectorlayerjoininfo.h.


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