[FEATURE] Duplicate features including children (one level deep) when…

… relation strength is competition - configuration for the relationsstrength in the relation GUI `[needs-docs]`

python/core/qgsrelation.sip

@@ -19,6 +19,13 @@ class QgsRelation
 %End
   public:
 
+    enum RelationStrength
+    {
+      Association,
+      Composition
+
+    };
+
 
     QgsRelation();
 %Docstring
@@ -53,6 +60,12 @@ class QgsRelation
  Set a name for this relation
 %End
 
+    void setStrength( const RelationStrength &strength );
+%Docstring
+ Set a strength for this relation
+.. versionadded:: 3.0
+%End
+
     void setReferencingLayer( const QString &id );
 %Docstring
  Set the referencing (child) layer id. This layer will be searched in the registry.
@@ -158,6 +171,15 @@ class QgsRelation
  :rtype: str
 %End
 
+    RelationStrength strength() const;
+%Docstring
+ Returns the relation strength as a string
+
+ :return: strength
+.. versionadded:: 3.0
+ :rtype: RelationStrength
+%End
+
     QString id() const;
 %Docstring
  A (project-wide) unique id for this relation

python/core/qgsvectorlayerutils.sip

@@ -22,6 +22,38 @@ class QgsVectorLayerUtils
 %End
   public:
 
+    class QgsDuplicateFeatureContext
+{
+%Docstring
+ Contains mainly the QMap with QgsVectorLayer and QgsFeatureIds do list all the duplicated features
+
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsvectorlayerutils.h"
+%End
+      public:
+
+        QgsDuplicateFeatureContext();
+
+        QList<QgsVectorLayer *> layers() const;
+%Docstring
+ Returns all the layers in the member QMap mDuplicatedFeatures
+.. versionadded:: 3.0
+ :rtype: list of QgsVectorLayer
+%End
+
+        QgsFeatureIds duplicatedFeatures( QgsVectorLayer *layer ) const;
+%Docstring
+ Returns the duplicated features in the given layer
+.. versionadded:: 3.0
+ :rtype: QgsFeatureIds
+%End
+
+
+    };
+
     static bool valueExists( const QgsVectorLayer *layer, int fieldIndex, const QVariant &value, const QgsFeatureIds &ignoreIds = QgsFeatureIds() );
 %Docstring
  Returns true if the specified value already exists within a field. This method can be used to test for uniqueness
@@ -62,8 +94,18 @@ class QgsVectorLayerUtils
  :rtype: QgsFeature
 %End
 
+    static QgsFeature duplicateFeature( QgsVectorLayer *layer, const QgsFeature &feature, QgsProject *project, int depth, QgsDuplicateFeatureContext &duplicateFeatureContext /Out/ );
+%Docstring
+ Duplicates a feature and it's children (one level deep). It calls CreateFeature, so
+ default values and constraints (e.g., unique constraints) will automatically be handled.
+ The duplicated feature will be automatically inserted into the layer.
+.. versionadded:: 3.0
+ :rtype: QgsFeature
+%End
+
 };
 
+
 /************************************************************************
  * This file has been generated automatically from                      *
  *                                                                      *

src/app/qgsdiscoverrelationsdlg.cpp

@@ -43,6 +43,17 @@ void QgsDiscoverRelationsDlg::addRelation( const QgsRelation &rel )
   mRelationsTable->setItem( row, 2, new QTableWidgetItem( rel.fieldPairs().at( 0 ).referencingField() ) );
   mRelationsTable->setItem( row, 3, new QTableWidgetItem( rel.referencedLayer()->name() ) );
   mRelationsTable->setItem( row, 4, new QTableWidgetItem( rel.fieldPairs().at( 0 ).referencedField() ) );
+  if ( rel.strength() == QgsRelation::RelationStrength::Composition )
+  {
+    mRelationsTable->setItem( row, 5, new QTableWidgetItem( QStringLiteral( "Composition" ) ) );
+  }
+  else
+  {
+    mRelationsTable->setItem( row, 5, new QTableWidgetItem( QStringLiteral( "Association" ) ) );
+  }
+
+  mRelationsTable->item( row, 5 )->setToolTip( QStringLiteral( "Composition (child features will be copied too) or Association" ) );
+
 }
 
 QList<QgsRelation> QgsDiscoverRelationsDlg::relations() const

src/app/qgsrelationadddlg.cpp

@@ -33,6 +33,10 @@ QgsRelationAddDlg::QgsRelationAddDlg( QWidget *parent )
   mCbxReferencedLayer->setFilters( QgsMapLayerProxyModel::VectorLayer );
   mCbxReferencedField->setLayer( mCbxReferencedLayer->currentLayer() );
 
+  mCbxRelationStrength->addItem( "Association", QVariant::fromValue( QgsRelation::RelationStrength::Association ) );
+  mCbxRelationStrength->addItem( "Composition", QVariant::fromValue( QgsRelation::RelationStrength::Composition ) );
+  mCbxRelationStrength->setToolTip( QStringLiteral( "Composition (child features will be copied too) or Association" ) );
+
   mTxtRelationId->setPlaceholderText( tr( "[Generated automatically]" ) );
   checkDefinitionValid();
 
@@ -74,6 +78,10 @@ QString QgsRelationAddDlg::relationName()
   return mTxtRelationName->text();
 }
 
+QgsRelation::RelationStrength QgsRelationAddDlg::relationStrength()
+{
+  return mCbxRelationStrength->currentData().value<QgsRelation::RelationStrength>();
+}
 
 void QgsRelationAddDlg::checkDefinitionValid()
 {

src/app/qgsrelationadddlg.h

@@ -18,6 +18,7 @@
 #include <QDialog>
 #include "ui_qgsrelationadddlgbase.h"
 #include "qgis_app.h"
+#include "qgsrelation.h"
 
 class QgsVectorLayer;
 
@@ -33,7 +34,7 @@ class APP_EXPORT QgsRelationAddDlg : public QDialog, private Ui::QgsRelationAddD
     QList< QPair< QString, QString > > references();
     QString relationId();
     QString relationName();
-
+    QgsRelation::RelationStrength relationStrength();
 
   private slots:
 

src/app/qgsrelationmanagerdialog.cpp

@@ -77,6 +77,19 @@ void QgsRelationManagerDialog::addRelation( const QgsRelation &rel )
   item = new QTableWidgetItem( rel.id() );
   item->setFlags( Qt::ItemIsEditable );
   mRelationsTable->setItem( row, 5, item );
+
+
+  if ( rel.strength() == QgsRelation::RelationStrength::Composition )
+  {
+    item = new QTableWidgetItem( QStringLiteral( "Composition" ) );
+  }
+  else
+  {
+    item = new QTableWidgetItem( QStringLiteral( "Association" ) );
+  }
+  item->setFlags( Qt::ItemIsEditable );
+  mRelationsTable->setItem( row, 6, item );
+
   mRelationsTable->setSortingEnabled( true );
 }
 
@@ -116,6 +129,7 @@ void QgsRelationManagerDialog::mBtnAddRelation_clicked()
     relation.setId( relationId );
     relation.addFieldPair( addDlg.references().at( 0 ).first, addDlg.references().at( 0 ).second );
     relation.setName( addDlg.relationName() );
+    relation.setStrength( addDlg.relationStrength() );
 
     addRelation( relation );
   }

src/core/qgsrelation.cpp

@@ -36,6 +36,7 @@ QgsRelation QgsRelation::createFromXml( const QDomNode &node )
   QString referencedLayerId = elem.attribute( QStringLiteral( "referencedLayer" ) );
   QString id = elem.attribute( QStringLiteral( "id" ) );
   QString name = elem.attribute( QStringLiteral( "name" ) );
+  QString strength = elem.attribute( QStringLiteral( "strength" ) );
 
   const QMap<QString, QgsMapLayer *> &mapLayers = QgsProject::instance()->mapLayers();
 
@@ -66,6 +67,14 @@ QgsRelation QgsRelation::createFromXml( const QDomNode &node )
   relation.mReferencedLayer = qobject_cast<QgsVectorLayer *>( referencedLayer );
   relation.mRelationId = id;
   relation.mRelationName = name;
+  if ( strength == "Composition" )
+  {
+    relation.mRelationStrength = RelationStrength::Composition;
+  }
+  else
+  {
+    relation.mRelationStrength = RelationStrength::Association;
+  }
 
   QDomNodeList references = elem.elementsByTagName( QStringLiteral( "fieldRef" ) );
   for ( int i = 0; i < references.size(); ++i )
@@ -90,6 +99,14 @@ void QgsRelation::writeXml( QDomNode &node, QDomDocument &doc ) const
   elem.setAttribute( QStringLiteral( "name" ), mRelationName );
   elem.setAttribute( QStringLiteral( "referencingLayer" ), mReferencingLayerId );
   elem.setAttribute( QStringLiteral( "referencedLayer" ), mReferencedLayerId );
+  if ( mRelationStrength == RelationStrength::Composition )
+  {
+    elem.setAttribute( QStringLiteral( "strength" ), QStringLiteral( "Composition" ) );
+  }
+  else
+  {
+    elem.setAttribute( QStringLiteral( "strength" ), QStringLiteral( "Association" ) );
+  }
 
   Q_FOREACH ( const FieldPair &fields, mFieldPairs )
   {
@@ -114,6 +131,12 @@ void QgsRelation::setName( const QString &name )
   mRelationName = name;
 }
 
+
+void QgsRelation::setStrength( const RelationStrength &strength )
+{
+  mRelationStrength = strength;
+}
+
 void QgsRelation::setReferencingLayer( const QString &id )
 {
   mReferencingLayerId = id;
@@ -206,6 +229,11 @@ QString QgsRelation::name() const
   return mRelationName;
 }
 
+QgsRelation::RelationStrength QgsRelation::strength() const
+{
+  return mRelationStrength;
+}
+
 QString QgsRelation::id() const
 {
   return mRelationId;

src/core/qgsrelation.h

@@ -48,6 +48,17 @@ class CORE_EXPORT QgsRelation
 
   public:
 
+    /**
+     * enum for the relation strength
+     * Association, Composition
+     */
+    enum RelationStrength
+    {
+      Association, //!< Loose relation, related elements are not part of the parent and a parent copy will not copy any children.
+      Composition  //!< Fix relation, related elements are part of the parent and a parent copy will copy any children or delete of parent will delete children
+
+    };
+
 #ifndef SIP_RUN
 
     /**
@@ -109,6 +120,12 @@ class CORE_EXPORT QgsRelation
      */
     void setName( const QString &name );
 
+    /**
+     * Set a strength for this relation
+     * \since QGIS 3.0
+     */
+    void setStrength( const RelationStrength &strength );
+
     /**
      * Set the referencing (child) layer id. This layer will be searched in the registry.
      */
@@ -214,6 +231,14 @@ class CORE_EXPORT QgsRelation
      */
     QString name() const;
 
+    /**
+     * Returns the relation strength as a string
+     *
+     * \returns strength
+     * \since QGIS 3.0
+     */
+    RelationStrength strength() const;
+
     /**
      * A (project-wide) unique id for this relation
      *
@@ -345,6 +370,8 @@ class CORE_EXPORT QgsRelation
     //! The parent layer
     QgsVectorLayer *mReferencedLayer = nullptr;
 
+    RelationStrength mRelationStrength;
+
     /**
      * A list of fields which define the relation.
      *  In most cases there will be only one value, but multiple values
@@ -357,5 +384,6 @@ class CORE_EXPORT QgsRelation
 
 // Register QgsRelation for usage with QVariant
 Q_DECLARE_METATYPE( QgsRelation )
+Q_DECLARE_METATYPE( QgsRelation::RelationStrength )
 
 #endif // QGSRELATION_H