Pass project when creating relation from Xml

Fix dependency inconsistency to project from QgsRelationManager by forcing 'QgsRelation::createFromXml' to rely on project passed to 'QgsRelationManager' instead of using 'QgisProject::instance()'
qgis · Dec 20, 2019 · 5bf8d2c · 5bf8d2c
1 parent 602febc
commit 5bf8d2c
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Showing 15 changed files with 1,138 additions and 11 deletions.
diff --git a/python/core/auto_generated/qgsrelation.sip.in b/python/core/auto_generated/qgsrelation.sip.in
@@ -11,7 +11,6 @@
 
 
 
-
 class QgsRelation
 {
 
@@ -37,6 +36,11 @@ Default constructor. Creates an invalid relation.
 %End
     ~QgsRelation();
 
+    QgsRelation( const QgsRelationContext &context );
+%Docstring
+Constructor with context. Creates an invalid relation.
+%End
+
     QgsRelation( const QgsRelation &other );
 %Docstring
 Copies a relation.
@@ -45,12 +49,13 @@ changed.
 %End
 
 
-    static QgsRelation createFromXml( const QDomNode &node, QgsReadWriteContext &context );
+    static QgsRelation createFromXml( const QDomNode &node, QgsReadWriteContext &context, const QgsRelationContext &relcontext = QgsRelationContext() );
 %Docstring
 Creates a relation from an XML structure. Used for reading .qgs projects.
 
 :param node: The dom node containing the relation information
 :param context: to pass project translator
+:param context: a relation context
 
 :return: A relation
 %End

diff --git a/python/core/auto_generated/qgsrelationcontext.sip.in b/python/core/auto_generated/qgsrelationcontext.sip.in
@@ -0,0 +1,56 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsrelationcontext.h                                        *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+class QgsRelationContext
+{
+%Docstring
+Context for relations. Used to resolve layers from projects.
+
+.. versionadded:: 3.11
+%End
+
+%TypeHeaderCode
+#include "qgsrelationcontext.h"
+%End
+  public:
+
+    QgsRelationContext( QgsProject *project = 0 );
+%Docstring
+Constructor for QgsRelationContext.
+%End
+
+    const QgsProject *project() const;
+%Docstring
+Gets the associated project
+
+If there is no associated project, then it will return the global
+project instance
+%End
+
+    ~QgsRelationContext();
+
+    QgsRelationContext( const QgsRelationContext &other );
+%Docstring
+Copy constructor
+%End
+
+
+};
+
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsrelationcontext.h                                        *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
diff --git a/python/core/auto_generated/qgsrelationmanager.sip.in b/python/core/auto_generated/qgsrelationmanager.sip.in
@@ -26,6 +26,11 @@ This class manages a set of relations between layers.
 Constructor for QgsRelationManager.
 
 :param project: associated project (used to notify project of changes)
+%End
+
+    QgsRelationContext context() const;
+%Docstring
+Gets the relation context
 %End
 
     void setRelations( const QList<QgsRelation> &relations );

diff --git a/python/core/core_auto.sip b/python/core/core_auto.sip
@@ -163,6 +163,7 @@
 %Include auto_generated/qgsreadwritecontext.sip
 %Include auto_generated/qgsreadwritelocker.sip
 %Include auto_generated/qgsrelation.sip
+%Include auto_generated/qgsrelationcontext.sip
 %Include auto_generated/qgsrelationmanager.sip
 %Include auto_generated/qgsrenderchecker.sip
 %Include auto_generated/qgsrendercontext.sip

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
+  qgsrelationcontext.cpp
   qgsweakrelation.cpp
   qgsrelationmanager.cpp
   qgsrenderchecker.cpp
@@ -841,6 +842,7 @@ SET(QGIS_CORE_HDRS
   qgsreadwritecontext.h
   qgsreadwritelocker.h
   qgsrelation.h
+  qgsrelationcontext.h
   qgsweakrelation.h
   qgsrelationmanager.h
   qgsrenderchecker.h

diff --git a/src/core/qgsrelation.cpp b/src/core/qgsrelation.cpp
@@ -27,20 +27,28 @@ QgsRelation::QgsRelation()
 {
 }
 
+QgsRelation::QgsRelation( const QgsRelationContext &context )
+  : d( new QgsRelationPrivate() )
+  , mContext( context )
+{
+}
+
 QgsRelation::~QgsRelation() = default;
 
 QgsRelation::QgsRelation( const QgsRelation &other )
   : d( other.d )
+  , mContext( other.mContext )
 {
 }
 
 QgsRelation &QgsRelation::operator=( const QgsRelation &other )
 {
   d = other.d;
+  mContext = other.mContext;
   return *this;
 }
 
-QgsRelation QgsRelation::createFromXml( const QDomNode &node, QgsReadWriteContext &context )
+QgsRelation QgsRelation::createFromXml( const QDomNode &node, QgsReadWriteContext &context,  const QgsRelationContext &relationContext )
 {
   QDomElement elem = node.toElement();
 
@@ -49,15 +57,15 @@ QgsRelation QgsRelation::createFromXml( const QDomNode &node, QgsReadWriteContex
     QgsLogger::warning( QApplication::translate( "QgsRelation", "Cannot create relation. Unexpected tag '%1'" ).arg( elem.tagName() ) );
   }
 
-  QgsRelation relation;
+  QgsRelation relation( relationContext );
 
   QString referencingLayerId = elem.attribute( QStringLiteral( "referencingLayer" ) );
   QString referencedLayerId = elem.attribute( QStringLiteral( "referencedLayer" ) );
   QString id = elem.attribute( QStringLiteral( "id" ) );
   QString name = context.projectTranslator()->translate( QStringLiteral( "project:relations" ), elem.attribute( QStringLiteral( "name" ) ) );
   QString strength = elem.attribute( QStringLiteral( "strength" ) );
 
-  const QMap<QString, QgsMapLayer *> &mapLayers = QgsProject::instance()->mapLayers();
+  QMap<QString, QgsMapLayer *> mapLayers = relationContext.project()->mapLayers();
 
   QgsMapLayer *referencingLayer = mapLayers[referencingLayerId];
   QgsMapLayer *referencedLayer = mapLayers[referencedLayerId];
@@ -355,7 +363,7 @@ QString QgsRelation::resolveReferencingField( const QString &referencedField ) c
 
 void QgsRelation::updateRelationStatus()
 {
-  const QMap<QString, QgsMapLayer *> &mapLayers = QgsProject::instance()->mapLayers();
+  const QMap<QString, QgsMapLayer *> &mapLayers = mContext.project()->mapLayers();
 
   d->mReferencingLayer = qobject_cast<QgsVectorLayer *>( mapLayers[d->mReferencingLayerId] );
   d->mReferencedLayer = qobject_cast<QgsVectorLayer *>( mapLayers[d->mReferencedLayerId] );

diff --git a/src/core/qgsrelation.h b/src/core/qgsrelation.h
@@ -23,6 +23,7 @@
 #include "qgis_core.h"
 #include "qgsfields.h"
 #include "qgsreadwritecontext.h"
+#include "qgsrelationcontext.h"
 
 #include "qgis_sip.h"
 
@@ -33,7 +34,6 @@ class QgsAttributes;
 class QgsVectorLayer;
 class QgsRelationPrivate;
 
-
 /**
  * \ingroup core
  * \class QgsRelation
@@ -96,6 +96,11 @@ class CORE_EXPORT QgsRelation
     QgsRelation();
     ~QgsRelation();
 
+    /**
+     * Constructor with context. Creates an invalid relation.
+     */
+    QgsRelation( const QgsRelationContext &context );
+
     /**
      * Copies a relation.
      * This makes a shallow copy, relations are implicitly shared and only duplicated when the copy is
@@ -115,10 +120,11 @@ class CORE_EXPORT QgsRelation
      *
      * \param node The dom node containing the relation information
      * \param context to pass project translator
+     * \param context a relation context
      *
      * \returns A relation
      */
-    static QgsRelation createFromXml( const QDomNode &node, QgsReadWriteContext &context );
+    static QgsRelation createFromXml( const QDomNode &node, QgsReadWriteContext &context, const QgsRelationContext &relcontext = QgsRelationContext() );
 
     /**
      * Writes a relation to an XML structure. Used for saving .qgs projects
@@ -378,6 +384,8 @@ class CORE_EXPORT QgsRelation
   private:
 
     mutable QExplicitlySharedDataPointer<QgsRelationPrivate> d;
+
+    QgsRelationContext mContext;
 };
 
 // Register QgsRelation for usage with QVariant

diff --git a/src/core/qgsrelationcontext.cpp b/src/core/qgsrelationcontext.cpp
@@ -0,0 +1,46 @@
+/***************************************************************************
+    qgsrelationcontext.cpp
+     --------------------------------------
+    Date                 : 20.12.2019
+    Copyright            : (C) 2019 David Marteau
+    Email                : dmarteau at 3liz dot com
+ ***************************************************************************
+ *                                                                         *
+ *   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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+#include "qgsproject.h"
+#include "qgsrelationcontext.h"
+
+QgsRelationContext::QgsRelationContext( QgsProject *project )
+  : mProject( project )
+{
+}
+
+QgsRelationContext::~QgsRelationContext() = default;
+
+QgsRelationContext::QgsRelationContext( const QgsRelationContext &other )
+  : mProject( other.mProject )
+{
+}
+
+QgsRelationContext &QgsRelationContext::operator=( const QgsRelationContext &other )
+{
+  mProject = other.mProject;
+  return *this;
+}
+
+const QgsProject *QgsRelationContext::project() const
+{
+  if ( mProject )
+  {
+    return mProject;
+  }
+
+  // Fallback to qgis instance
+  return QgsProject::instance();
+}
+
diff --git a/src/core/qgsrelationcontext.h b/src/core/qgsrelationcontext.h
@@ -0,0 +1,66 @@
+/***************************************************************************
+    qgsrelationcontext.h
+     --------------------------------------
+    Date                 : 20.12.2019
+    Copyright            : (C) 2019 David Marteau
+    Email                : dmarteau at 3liz dot com
+ ***************************************************************************
+ *                                                                         *
+ *   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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSRELATIONCONTEXT_H
+#define QGSRELATIONCONTEXT_H
+
+#include "qgis_core.h"
+#include "qgis_sip.h"
+
+class QgsProject;
+
+
+/**
+ * \ingroup core
+ * \class QgsRelationContext
+ * Context for relations. Used to resolve layers from projects.
+ * \since QGIS 3.11
+ */
+class CORE_EXPORT QgsRelationContext
+{
+  public:
+
+    /**
+     * Constructor for QgsRelationContext.
+     */
+    QgsRelationContext( QgsProject *project = nullptr );
+
+    /**
+     * Gets the associated project
+     *
+     * If there is no associated project, then it will return the global
+     * project instance
+     */
+    const QgsProject *project() const;
+
+    ~QgsRelationContext();
+
+    /**
+     * Copy constructor
+     */
+    QgsRelationContext( const QgsRelationContext &other );
+
+    /**
+     * Assignment operator
+     */
+    QgsRelationContext &operator=( const QgsRelationContext &other );
+
+  private:
+    QgsProject *mProject = nullptr;
+
+};
+
+#endif // QGSRELATIONCONTEXT_H
+
diff --git a/src/core/qgsrelationmanager.cpp b/src/core/qgsrelationmanager.cpp
@@ -25,7 +25,7 @@ QgsRelationManager::QgsRelationManager( QgsProject *project )
   : QObject( project )
   , mProject( project )
 {
-  if ( mProject )
+  if ( project )
   {
     // TODO: QGIS 4 remove: relations are now stored with the layer style
     connect( project, &QgsProject::readProjectWithContext, this, &QgsRelationManager::readProject );
@@ -36,6 +36,11 @@ QgsRelationManager::QgsRelationManager( QgsProject *project )
   }
 }
 
+QgsRelationContext QgsRelationManager::context() const
+{
+  return QgsRelationContext( mProject );
+}
+
 void QgsRelationManager::setRelations( const QList<QgsRelation> &relations )
 {
   mRelations.clear();
@@ -59,9 +64,10 @@ void QgsRelationManager::addRelation( const QgsRelation &relation )
     return;
 
   mRelations.insert( relation.id(), relation );
-
   if ( mProject )
+  {
     mProject->setDirty( true );
+  }
   emit changed();
 }
 
@@ -179,12 +185,14 @@ void QgsRelationManager::readProject( const QDomDocument &doc, QgsReadWriteConte
   QDomNodeList nodes = doc.elementsByTagName( QStringLiteral( "relations" ) );
   if ( nodes.count() )
   {
+    QgsRelationContext relcontext( mProject );
+
     QDomNode node = nodes.item( 0 );
     QDomNodeList relationNodes = node.childNodes();
     int relCount = relationNodes.count();
     for ( int i = 0; i < relCount; ++i )
     {
-      addRelation( QgsRelation::createFromXml( relationNodes.at( i ), context ) );
+      addRelation( QgsRelation::createFromXml( relationNodes.at( i ), context, relcontext ) );
     }
   }
   else