/***************************************************************************
qgsrelation.sip
--------------------------------------
Date : 29.4.2013
Copyright : (C) 2013 Matthias Kuhn
Email : matthias at opengis dot ch
***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
class QgsRelation
{
%TypeHeaderCode
#include <qgsrelation.h>
%End
public:
/**
* Default constructor. Creates an invalid relation.
*/
QgsRelation();
/**
* Creates a relation from an XML structure. Used for reading .qgs projects.
*
* @param node The dom node containing the relation information
*
* @return A relation
*/
static QgsRelation createFromXml( const QDomNode& node );
/**
* Writes a relation to an XML structure. Used for saving .qgs projects
*
* @param node The parent node in which the relation will be created
* @param doc The document in which the relation will be saved
*/
void writeXml( QDomNode& node, QDomDocument& doc ) const;
/**
* Set a name for this relation
*
* @param id
*/
void setRelationId( const QString& id );
/**
* Set a name for this relation
*
* @param name
*/
void setRelationName( const QString& name );
/**
* Set the referencing (child) layer id. This layer will be searched in the registry.
*
* @param id
*/
void setReferencingLayer( const QString& id );
/**
* Set the referenced (parent) layer id. This layer will be searched in the registry.
*
* @param id
*/
void setReferencedLayer( const QString& id );
/**
* Add a field pairs which is part of this relation
* The first element of each pair are the field names of the foreign key.
* The second element of each pair are the field names of the matching primary key.
*
* @param referencingField The field name on the referencing (child) layer (FK)
* @param referencedField The field name on the referenced (parent) layer (PK)
*/
void addFieldPair( const QString& referencingField, const QString& referencedField );
/**
* Add a field pairs which is part of this relation
* The first element of each pair are the field names of the foreign key.
* The second element of each pair are the field names of the matching primary key.
*
* @param fieldPair A pair of two strings
* @note not available in python bindings
*/
// void addFieldPair( const FieldPair& fieldPair );
/**
* Creates an iterator which returns all the features on the referencing (child) layer
* which have a foreign key pointing to the provided feature.
*
* @param feature A feature from the referenced (parent) layer
*
* @return An iterator with all the referenced features
* @see getRelatedFeaturesRequest()
* @see getRelatedFeaturesFilter()
*/
QgsFeatureIterator getRelatedFeatures( const QgsFeature& feature ) const;
/**
* Creates a request to return all the features on the referencing (child) layer
* which have a foreign key pointing to the provided feature.
*
* @param feature A feature from the referenced (parent) layer
*
* @return A request for all the referencing features
* @see getRelatedFeatures()
* @see getRelatedFeaturesFilter()
*/
QgsFeatureRequest getRelatedFeaturesRequest( const QgsFeature& feature ) const;
/** Returns a filter expression which returns all the features on the referencing (child) layer
* which have a foreign key pointing to the provided feature.
* @param feature A feature from the referenced (parent) layer
* @return expression filter string for all the referencing features
* @note added in QGIS 2.16
* @see getRelatedFeatures()
* @see getRelatedFeaturesRequest()
*/
QString getRelatedFeaturesFilter( const QgsFeature& feature ) const;
/**
* Creates a request to return the feature on the referenced (parent) layer
* which is referenced by the provided feature.
*
* @param attributes An attribute vector containing the foreign key
*
* @return A request the referenced feature
* @note not available in python bindings
*/
QgsFeatureRequest getReferencedFeatureRequest( const QgsAttributes& attributes ) const;
/**
* Creates a request to return the feature on the referenced (parent) layer
* which is referenced by the provided feature.
*
* @param feature A feature from the referencing (child) layer
*
* @return A request the referenced feature
*/
QgsFeatureRequest getReferencedFeatureRequest( const QgsFeature& feature ) const;
/**
* Creates a request to return the feature on the referenced (parent) layer
* which is referenced by the provided feature.
*
* @param feature A feature from the referencing (child) layer
*
* @return A request the referenced feature
*/
QgsFeature getReferencedFeature( const QgsFeature& feature ) const;
/**
* Returns a human readable name for this relation. Mostly used as title for the children.
*
* @see id()
*
* @return A name
*/
QString name() const;
/**
* A (project-wide) unique id for this relation
*
* @return The id
*/
QString id() const;
/**
* Generate a (project-wide) unique id for this relation
* @note added in QGIS 3.0
*/
void generateId();
/**
* Access the referencing (child) layer's id
* This is the layer which has the field(s) which point to another layer
*
* @return The id of the referencing layer
*/
QString referencingLayerId() const;
/**
* Access the referencing (child) layer
* This is the layer which has the field(s) which point to another layer
*
* @return The referencing layer
*/
QgsVectorLayer* referencingLayer() const;
/**
* Access the referenced (parent) layer's id
*
* @return The id of the referenced layer
*/
QString referencedLayerId() const;
/**
* Access the referenced (parent) layer
*
* @return referenced layer
*/
QgsVectorLayer* referencedLayer() const;
/**
* Returns the field pairs which form this relation
* The first element of each pair are the field names fo the foreign key.
* The second element of each pair are the field names of the matching primary key.
*
* @return The fields forming the relation
*/
QMap< QString, QString > fieldPairs() const;
%MethodCode
const QList< QgsRelation::FieldPair >& pairs = sipCpp->fieldPairs();
sipRes = new QMap< QString, QString >();
Q_FOREACH( const QgsRelation::FieldPair& pair, pairs )
{
sipRes->insert( pair.first, pair.second );
}
%End
/**
* Returns a list of attributes used to form the referenced fields
* (most likely primary key) on the referenced (parent) layer.
*
* @return A list of attributes
*/
QgsAttributeList referencedFields() const;
/**
* Returns a list of attributes used to form the referencing fields
* (foreign key) on the referencing (child) layer.
*
* @return A list of attributes
*/
QgsAttributeList referencingFields() const;
/**
* Returns the validity of this relation. Don't use the information if it's not valid.
*
* @return true if the relation is valid
*/
bool isValid() const;
/**
* Compares the two QgsRelation, ignoring the name and the ID.
*
* @param other The other relation
* @return true if they are similar
* @note added in QGIS 3.0
*/
bool hasEqualDefinition( const QgsRelation& other ) const;
protected:
/**
* Updates the validity status of this relation.
* Will be called internally whenever a member is changed.
*/
void updateRelationStatus();
};