Weak relations and auto-restore when loading a style

qgis · Dec 19, 2019 · 90ac90b · 90ac90b
1 parent 76f9d16
commit 90ac90b
Show file tree

Hide file tree

Showing 14 changed files with 453 additions and 18 deletions.
diff --git a/python/core/auto_generated/qgsmaplayer.sip.in b/python/core/auto_generated/qgsmaplayer.sip.in
@@ -91,6 +91,7 @@ This is the base class for all map layer types (vector, raster).
       Rendering,
       CustomProperties,
       GeometryOptions,
+      Relations,
       AllStyleCategories
     };
     typedef QFlags<QgsMapLayer::StyleCategory> StyleCategories;

diff --git a/python/core/auto_generated/qgsrelationmanager.sip.in b/python/core/auto_generated/qgsrelationmanager.sip.in
@@ -104,7 +104,7 @@ Gets all relations where the specified layer (and field) is the referencing part
 :return: A list of relations matching the given layer and fieldIdx.
 %End
 
-    QList<QgsRelation> referencedRelations( QgsVectorLayer *layer = 0 ) const;
+    QList<QgsRelation> referencedRelations( const QgsVectorLayer *layer = 0 ) const;
 %Docstring
 Gets all relations where this layer is the referenced part (i.e. the parent table with the primary key being referenced from another layer).
 

diff --git a/python/core/auto_generated/qgsvectorlayer.sip.in b/python/core/auto_generated/qgsvectorlayer.sip.in
@@ -2014,6 +2014,8 @@ Returns the layer's relations, where the foreign key is on this layer.
 :return: A list of relations
 %End
 
+
+
     QgsVectorLayerEditBuffer *editBuffer();
 %Docstring
 Buffer with uncommitted editing operations. Only valid after editing has been turned on.

diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
@@ -75,9 +75,11 @@
 
 #include "qgssettings.h"
 #include "qgsnetworkaccessmanager.h"
+#include "qgsrelationmanager.h"
 #include "qgsapplication.h"
 #include "qgslayerstylingwidget.h"
 #include "qgstaskmanager.h"
+#include "qgsweakrelation.h"
 #include "qgsziputils.h"
 #include "qgsbrowserguimodel.h"
 #include "qgsvectorlayerjoinbuffer.h"
@@ -667,13 +669,24 @@ void QgisApp::onActiveLayerChanged( QgsMapLayer *layer )
 
 void QgisApp::vectorLayerStyleLoaded( QgsMapLayer::StyleCategories categories )
 {
-  if ( categories.testFlag( QgsMapLayer::StyleCategory::Forms ) )
+
+  QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( sender() );
+
+  if ( vl && vl->isValid( ) )
   {
-    QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( sender() );
-    if ( vl && vl->isValid( ) )
+
+    // Check broken dependencies in forms
+    if ( categories.testFlag( QgsMapLayer::StyleCategory::Forms ) )
     {
       checkVectorLayerDependencies( vl );
     }
+
+    // Check broken relations and try to restore them
+    if ( categories.testFlag( QgsMapLayer::StyleCategory::Relations ) )
+    {
+      checkVectorLayerRelations( vl );
+    }
+
   }
 }
 
@@ -1995,17 +2008,18 @@ QgsMessageBar *QgisApp::visibleMessageBar()
   }
 }
 
-QList<QgsVectorLayerRef> QgisApp::findBrokenWidgetDependencies( QgsVectorLayer *vl )
+const QList<QgsVectorLayerRef> QgisApp::findBrokenLayerDependencies( QgsVectorLayer *vl ) const
 {
   QList<QgsVectorLayerRef> brokenDependencies;
+
   // Check for missing layer widget dependencies
   for ( int i = 0; i < vl->fields().count(); i++ )
   {
     const QgsEditorWidgetSetup setup = QgsGui::editorWidgetRegistry()->findBest( vl, vl->fields().field( i ).name() );
     QgsFieldFormatter *fieldFormatter = QgsApplication::fieldFormatterRegistry()->fieldFormatter( setup.type() );
     if ( fieldFormatter )
     {
-      const auto constDependencies { fieldFormatter->layerDependencies( setup.config() ) };
+      const QList<QgsVectorLayerRef> constDependencies { fieldFormatter->layerDependencies( setup.config() ) };
       for ( const QgsVectorLayerRef &dependency : constDependencies )
       {
         const QgsVectorLayer *depVl { QgsVectorLayerRef( dependency ).resolveWeakly(
@@ -2018,14 +2032,61 @@ QList<QgsVectorLayerRef> QgisApp::findBrokenWidgetDependencies( QgsVectorLayer *
       }
     }
   }
+
+  // Check for layer weak relations
+  const QList<QgsWeakRelation> constWeakRelations { vl->weakRelations() };
+  for ( const QgsWeakRelation &rel : constWeakRelations )
+  {
+    QgsRelation relation { rel.resolvedRelation( QgsProject::instance(), QgsVectorLayerRef::MatchType::Name ) };
+    QgsVectorLayerRef dependency;
+    bool found = false;
+    if ( ! relation.isValid() )
+    {
+      // We need just the other side of the relation
+      if ( relation.referencedLayer() == vl )
+      {
+        dependency = rel.referencingLayer();
+        found = true;
+      }
+      else if ( relation.referencingLayer() == vl )
+      {
+        dependency = rel.referencedLayer();
+        found = true;
+      }
+      else
+      {
+        // Something wrong is going on here, maybe this relation
+        // does not really apply to this layer?
+        QgsMessageLog::logMessage( tr( "None of the layers in the relation stored in the style match the current layer, skipping relation id: %1." ).arg( relation.id() ) );
+      }
+
+      if ( found )
+      {
+        // Make sure we don't add it twice
+        bool refFound = false;
+        for ( const QgsVectorLayerRef &otherRef : qgis::as_const( brokenDependencies ) )
+        {
+          if ( dependency.layerId == otherRef.layerId || ( dependency.source == otherRef.source && dependency.provider == otherRef.provider ) )
+          {
+            refFound = true;
+            break;
+          }
+        }
+        if ( ! refFound )
+        {
+          brokenDependencies.append( dependency );
+        }
+      }
+    }
+  }
   return brokenDependencies;
 }
 
 void QgisApp::checkVectorLayerDependencies( QgsVectorLayer *vl )
 {
   if ( vl && vl->isValid() )
   {
-    const auto constDependencies { findBrokenWidgetDependencies( vl ) };
+    const auto constDependencies { findBrokenLayerDependencies( vl ) };
     for ( const QgsVectorLayerRef &dependency : constDependencies )
     {
       // try to aggressively resolve the broken dependencies
@@ -2115,6 +2176,31 @@ void QgisApp::checkVectorLayerDependencies( QgsVectorLayer *vl )
   }
 }
 
+void QgisApp::checkVectorLayerRelations( QgsVectorLayer *vectorLayer )
+{
+  if ( vectorLayer && vectorLayer->isValid() )
+  {
+    const QList<QgsWeakRelation> constWeakRelations { vectorLayer->weakRelations( ) };
+    for ( const QgsWeakRelation &rel : constWeakRelations )
+    {
+      QgsRelation relation { rel.resolvedRelation( QgsProject::instance(), QgsVectorLayerRef::MatchType::Name ) };
+      if ( relation.isValid() )
+      {
+        // Avoid duplicates
+        const QList<QgsRelation> constRelations { QgsProject::instance()->relationManager()->relations().values() };
+        for ( const QgsRelation &other : constRelations )
+        {
+          if ( relation.hasEqualDefinition( other ) )
+          {
+            continue;
+          }
+        }
+        QgsProject::instance()->relationManager()->addRelation( relation );
+      }
+    }
+  }
+}
+
 void QgisApp::dataSourceManager( const QString &pageName )
 {
   if ( ! mDataSourceManagerDialog )

diff --git a/src/app/qgisapp.h b/src/app/qgisapp.h
@@ -2025,16 +2025,26 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     QgsMessageBar *visibleMessageBar();
 
     /**
-     * Searches for layer widget dependencies
-     * \return a list of weak references to broken widget layer dependencies
+     * Searches for layer dependencies by querying widgets and the layer itself for broken relations
+     * \return a list of weak references to broken layer dependencies
      */
-    QList< QgsVectorLayerRef > findBrokenWidgetDependencies( QgsVectorLayer *vectorLayer );
+    const QList< QgsVectorLayerRef > findBrokenLayerDependencies( QgsVectorLayer *vectorLayer ) const;
 
     /**
-     * Scans the \a vectorLayer for broken dependencies and warns the user
+     * Scans the \a vectorLayer for broken dependencies and automatically
+     * try to load the missing layer and warns the user about the operation
+     * result.
      */
     void checkVectorLayerDependencies( QgsVectorLayer *vectorLayer );
 
+    /**
+     * Scans the \a vectorLayer for broken relations and automatically
+     * try to create the missing relation and warns the user about the operation
+     * result.
+     */
+    void checkVectorLayerRelations( QgsVectorLayer *vectorLayer );
+
+
     QgisAppStyleSheet *mStyleSheetBuilder = nullptr;
 
 

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
@@ -339,6 +339,7 @@ SET(QGIS_CORE_SRCS
   qgsreadwritecontext.cpp
   qgsreadwritelocker.cpp
   qgsrelation.cpp
+  qgsweakrelation.cpp
   qgsrelationmanager.cpp
   qgsrenderchecker.cpp
   qgsrendercontext.cpp
@@ -840,6 +841,7 @@ SET(QGIS_CORE_HDRS
   qgsreadwritecontext.h
   qgsreadwritelocker.h
   qgsrelation.h
+  qgsweakrelation.h
   qgsrelationmanager.h
   qgsrenderchecker.h
   qgsrendercontext.h

diff --git a/src/core/qgsmaplayer.cpp b/src/core/qgsmaplayer.cpp
@@ -267,9 +267,6 @@ bool QgsMapLayer::readLayerXml( const QDomElement &layerElement, QgsReadWriteCon
 
   QgsReadWriteContextCategoryPopper p = context.enterCategory( tr( "Layer" ), mne.text() );
 
-  // now let the children grab what they need from the Dom node.
-  layerError = !readXml( layerElement, context );
-
   // overwrite CRS with what we read from project file before the raster/vector
   // file reading functions changed it. They will if projections is specified in the file.
   // FIXME: is this necessary?
@@ -296,14 +293,16 @@ bool QgsMapLayer::readLayerXml( const QDomElement &layerElement, QgsReadWriteCon
   setRefreshOnNofifyMessage( layerElement.attribute( QStringLiteral( "refreshOnNotifyMessage" ), QString() ) );
   setRefreshOnNotifyEnabled( layerElement.attribute( QStringLiteral( "refreshOnNotifyEnabled" ), QStringLiteral( "0" ) ).toInt() );
 
-
   // set name
   mnl = layerElement.namedItem( QStringLiteral( "layername" ) );
   mne = mnl.toElement();
 
   //name can be translated
   setName( context.projectTranslator()->translate( QStringLiteral( "project:layers:%1" ).arg( layerElement.namedItem( QStringLiteral( "id" ) ).toElement().text() ), mne.text() ) );
 
+  // now let the children grab what they need from the Dom node.
+  layerError = !readXml( layerElement, context );
+
   //short name
   QDomElement shortNameElem = layerElement.firstChildElement( QStringLiteral( "shortname" ) );
   if ( !shortNameElem.isNull() )

diff --git a/src/core/qgsmaplayer.h b/src/core/qgsmaplayer.h
@@ -161,8 +161,9 @@ class CORE_EXPORT QgsMapLayer : public QObject
       Rendering          = 1 << 10, //!< Rendering: scale visibility, simplify method, opacity
       CustomProperties   = 1 << 11, //!< Custom properties (by plugins for instance)
       GeometryOptions    = 1 << 12, //!< Geometry validation configuration
+      Relations          = 1 << 13, //!< Relations
       AllStyleCategories = LayerConfiguration | Symbology | Symbology3D | Labeling | Fields | Forms | Actions |
-                           MapTips | Diagrams | AttributeTable | Rendering | CustomProperties | GeometryOptions,
+                           MapTips | Diagrams | AttributeTable | Rendering | CustomProperties | GeometryOptions | Relations,
     };
     Q_ENUM( StyleCategory )
     Q_DECLARE_FLAGS( StyleCategories, StyleCategory )

diff --git a/src/core/qgsrelationmanager.cpp b/src/core/qgsrelationmanager.cpp
@@ -27,8 +27,11 @@ QgsRelationManager::QgsRelationManager( QgsProject *project )
 {
   if ( mProject )
   {
+    // TODO: QGIS 4 remove: relations are now stored with the layer style
     connect( project, &QgsProject::readProjectWithContext, this, &QgsRelationManager::readProject );
+    // TODO: QGIS 4 remove: relations are now stored with the layer style
     connect( project, &QgsProject::writeProject, this, &QgsRelationManager::writeProject );
+
     connect( project, &QgsProject::layersRemoved, this, &QgsRelationManager::layersRemoved );
   }
 }
@@ -148,7 +151,7 @@ QList<QgsRelation> QgsRelationManager::referencingRelations( const QgsVectorLaye
   return relations;
 }
 
-QList<QgsRelation> QgsRelationManager::referencedRelations( QgsVectorLayer *layer ) const
+QList<QgsRelation> QgsRelationManager::referencedRelations( const QgsVectorLayer *layer ) const
 {
   if ( !layer )
   {

diff --git a/src/core/qgsrelationmanager.h b/src/core/qgsrelationmanager.h
@@ -121,7 +121,7 @@ class CORE_EXPORT QgsRelationManager : public QObject
      *
      * \returns A list of relations where the specified layer is the referenced part.
      */
-    QList<QgsRelation> referencedRelations( QgsVectorLayer *layer = nullptr ) const;
+    QList<QgsRelation> referencedRelations( const QgsVectorLayer *layer = nullptr ) const;
 
     /**
      * Discover all the relations available from the current layers.