Add API to set field split policy for vector layers

qgis · Mar 1, 2023 · edfb976 · edfb976
1 parent 3528d88
commit edfb976
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Showing 4 changed files with 159 additions and 2 deletions.
diff --git a/python/core/auto_generated/vector/qgsvectorlayer.sip.in b/python/core/auto_generated/vector/qgsvectorlayer.sip.in
@@ -2038,6 +2038,28 @@ Convenience function that returns the attribute alias if defined or the field na
 Returns a map of field name to attribute alias
 %End
 
+
+    void setFieldSplitPolicy( int index, Qgis::FieldDomainSplitPolicy policy );
+%Docstring
+Sets a split ``policy`` for the field with the specified index.
+
+:raises KeyError: if no field with the specified index exists
+
+.. versionadded:: 3.30
+%End
+
+%MethodCode
+    if ( a0 < 0 || a0 >= sipCpp->fields().count() )
+    {
+      PyErr_SetString( PyExc_KeyError, QByteArray::number( a0 ) );
+      sipIsErr = 1;
+    }
+    else
+    {
+      sipCpp->setFieldSplitPolicy( a0, a1 );
+    }
+%End
+
  QSet<QString> excludeAttributesWms() const /Deprecated/;
 %Docstring
 A set of attributes that are not advertised in WMS requests with QGIS server.

diff --git a/src/core/vector/qgsvectorlayer.cpp b/src/core/vector/qgsvectorlayer.cpp
@@ -2073,6 +2073,10 @@ bool QgsVectorLayer::setDataProvider( QString const &provider, const QgsDataProv
     {
       mAttributeAliasMap[ field.name() ] = field.alias();
     }
+    if ( !mAttributeSplitPolicy.contains( field.name() ) )
+    {
+      mAttributeSplitPolicy[ field.name() ] = field.splitPolicy();
+    }
   }
 
   if ( profile )
@@ -2383,6 +2387,22 @@ bool QgsVectorLayer::readSymbology( const QDomNode &layerNode, QString &errorMes
       }
     }
 
+    // IMPORTANT - we don't clear mAttributeSplitPolicy here, as it may contain policies which are coming direct
+    // from the data provider. Instead we leave any existing policies and only overwrite them if the style
+    // has a specific value for that field's policy
+    const QDomNode splitPoliciesNode = layerNode.namedItem( QStringLiteral( "splitPolicies" ) );
+    if ( !splitPoliciesNode.isNull() )
+    {
+      const QDomNodeList splitPolicyNodeList = splitPoliciesNode.toElement().elementsByTagName( QStringLiteral( "policy" ) );
+      for ( int i = 0; i < splitPolicyNodeList.size(); ++i )
+      {
+        const QDomElement splitPolicyElem = splitPolicyNodeList.at( i ).toElement();
+        const QString field = splitPolicyElem.attribute( QStringLiteral( "field" ) );
+        const Qgis::FieldDomainSplitPolicy policy = qgsEnumKeyToValue( splitPolicyElem.attribute( QStringLiteral( "policy" ) ), Qgis::FieldDomainSplitPolicy::Duplicate );
+        mAttributeSplitPolicy.insert( field, policy );
+      }
+    }
+
     // default expressions
     mDefaultExpressionMap.clear();
     QDomNode defaultsNode = layerNode.namedItem( QStringLiteral( "defaults" ) );
@@ -2879,6 +2899,19 @@ bool QgsVectorLayer::writeSymbology( QDomNode &node, QDomDocument &doc, QString
     }
     node.appendChild( aliasElem );
 
+    //split policies
+    {
+      QDomElement splitPoliciesElement = doc.createElement( QStringLiteral( "splitPolicies" ) );
+      for ( const QgsField &field : std::as_const( mFields ) )
+      {
+        QDomElement splitPolicyElem = doc.createElement( QStringLiteral( "policy" ) );
+        splitPolicyElem.setAttribute( QStringLiteral( "field" ), field.name() );
+        splitPolicyElem.setAttribute( QStringLiteral( "policy" ), qgsEnumValueToKey( field.splitPolicy() ) );
+        splitPoliciesElement.appendChild( splitPolicyElem );
+      }
+      node.appendChild( splitPoliciesElement );
+    }
+
     //default expressions
     QDomElement defaultsElem = doc.createElement( QStringLiteral( "defaults" ) );
     for ( const QgsField &field : std::as_const( mFields ) )
@@ -3362,6 +3395,21 @@ QgsStringMap QgsVectorLayer::attributeAliases() const
   return mAttributeAliasMap;
 }
 
+void QgsVectorLayer::setFieldSplitPolicy( int index, Qgis::FieldDomainSplitPolicy policy )
+{
+  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
+
+  if ( index < 0 || index >= fields().count() )
+    return;
+
+  const QString name = fields().at( index ).name();
+
+  mAttributeSplitPolicy.insert( name, policy );
+  mFields[ index ].setSplitPolicy( policy );
+  mEditFormConfig.setFields( mFields );
+  emit layerModified(); // TODO[MD]: should have a different signal?
+}
+
 QSet<QString> QgsVectorLayer::excludeAttributesWms() const
 {
   QGIS_PROTECT_QOBJECT_THREAD_ACCESS
@@ -4216,8 +4264,7 @@ void QgsVectorLayer::updateFields()
     mExpressionFieldBuffer->updateFields( mFields );
 
   // set aliases and default values
-  QMap< QString, QString >::const_iterator aliasIt = mAttributeAliasMap.constBegin();
-  for ( ; aliasIt != mAttributeAliasMap.constEnd(); ++aliasIt )
+  for ( auto aliasIt = mAttributeAliasMap.constBegin(); aliasIt != mAttributeAliasMap.constEnd(); ++aliasIt )
   {
     int index = mFields.lookupField( aliasIt.key() );
     if ( index < 0 )
@@ -4226,6 +4273,15 @@ void QgsVectorLayer::updateFields()
     mFields[ index ].setAlias( aliasIt.value() );
   }
 
+  for ( auto splitPolicyIt = mAttributeSplitPolicy.constBegin(); splitPolicyIt != mAttributeSplitPolicy.constEnd(); ++splitPolicyIt )
+  {
+    int index = mFields.lookupField( splitPolicyIt.key() );
+    if ( index < 0 )
+      continue;
+
+    mFields[ index ].setSplitPolicy( splitPolicyIt.value() );
+  }
+
   // Update configuration flags
   QMap< QString, QgsField::ConfigurationFlags >::const_iterator flagsIt = mFieldConfigurationFlags.constBegin();
   for ( ; flagsIt != mFieldConfigurationFlags.constEnd(); ++flagsIt )

diff --git a/src/core/vector/qgsvectorlayer.h b/src/core/vector/qgsvectorlayer.h
@@ -1921,6 +1921,37 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer, public QgsExpressionConte
     //! Returns a map of field name to attribute alias
     QgsStringMap attributeAliases() const;
 
+#ifndef SIP_RUN
+
+    /**
+     * Sets a split \a policy for the field with the specified index.
+     *
+     * \since QGIS 3.30
+     */
+    void setFieldSplitPolicy( int index, Qgis::FieldDomainSplitPolicy policy );
+#else
+
+    /**
+     * Sets a split \a policy for the field with the specified index.
+     *
+     * \throws KeyError if no field with the specified index exists
+     * \since QGIS 3.30
+     */
+    void setFieldSplitPolicy( int index, Qgis::FieldDomainSplitPolicy policy );
+
+    % MethodCode
+    if ( a0 < 0 || a0 >= sipCpp->fields().count() )
+    {
+      PyErr_SetString( PyExc_KeyError, QByteArray::number( a0 ) );
+      sipIsErr = 1;
+    }
+    else
+    {
+      sipCpp->setFieldSplitPolicy( a0, a1 );
+    }
+    % End
+#endif
+
     /**
      * A set of attributes that are not advertised in WMS requests with QGIS server.
      * \deprecated since QGIS 3.16, use fields().configurationFlags() instead
@@ -2949,6 +2980,9 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer, public QgsExpressionConte
     //! Map which stores default value expressions for fields
     QMap<QString, QgsDefaultValue> mDefaultExpressionMap;
 
+    //! Map that stores the split policy for attributes
+    QMap< QString, Qgis::FieldDomainSplitPolicy > mAttributeSplitPolicy;
+
     //! An internal structure to keep track of fields that have a defaultValueOnUpdate
     QSet<int> mDefaultValueOnUpdateFields;
 

diff --git a/tests/src/python/test_qgsvectorlayer.py b/tests/src/python/test_qgsvectorlayer.py
@@ -4438,6 +4438,51 @@ def testMapTips(self):
         self.assertFalse(vl.mapTipTemplate())
         self.assertFalse(vl.hasMapTips())
 
+    def test_split_policies(self):
+        vl = QgsVectorLayer('Point?crs=epsg:3111&field=field_default:integer&field=field_dupe:integer&field=field_unset:integer&field=field_ratio:integer', 'test', 'memory')
+        self.assertTrue(vl.isValid())
+
+        with self.assertRaises(KeyError):
+            vl.setFieldSplitPolicy(-1, Qgis.FieldDomainSplitPolicy.DefaultValue)
+        with self.assertRaises(KeyError):
+            vl.setFieldSplitPolicy(4, Qgis.FieldDomainSplitPolicy.DefaultValue)
+
+        vl.setFieldSplitPolicy(0, Qgis.FieldDomainSplitPolicy.DefaultValue)
+        vl.setFieldSplitPolicy(1, Qgis.FieldDomainSplitPolicy.Duplicate)
+        vl.setFieldSplitPolicy(2, Qgis.FieldDomainSplitPolicy.UnsetField)
+        vl.setFieldSplitPolicy(3, Qgis.FieldDomainSplitPolicy.GeometryRatio)
+
+        self.assertEqual(vl.fields()[0].splitPolicy(),
+                         Qgis.FieldDomainSplitPolicy.DefaultValue)
+        self.assertEqual(vl.fields()[1].splitPolicy(),
+                         Qgis.FieldDomainSplitPolicy.Duplicate)
+        self.assertEqual(vl.fields()[2].splitPolicy(),
+                         Qgis.FieldDomainSplitPolicy.UnsetField)
+        self.assertEqual(vl.fields()[3].splitPolicy(),
+                         Qgis.FieldDomainSplitPolicy.GeometryRatio)
+
+        p = QgsProject()
+        p.addMapLayer(vl)
+
+        # test saving and restoring split policies
+        with tempfile.TemporaryDirectory() as temp:
+            self.assertTrue(p.write(temp + '/test.qgs'))
+
+            p2 = QgsProject()
+            self.assertTrue(p2.read(temp + '/test.qgs'))
+
+            vl2 = list(p2.mapLayers().values())[0]
+            self.assertEqual(vl2.name(), vl.name())
+
+            self.assertEqual(vl2.fields()[0].splitPolicy(),
+                             Qgis.FieldDomainSplitPolicy.DefaultValue)
+            self.assertEqual(vl2.fields()[1].splitPolicy(),
+                             Qgis.FieldDomainSplitPolicy.Duplicate)
+            self.assertEqual(vl2.fields()[2].splitPolicy(),
+                             Qgis.FieldDomainSplitPolicy.UnsetField)
+            self.assertEqual(vl2.fields()[3].splitPolicy(),
+                             Qgis.FieldDomainSplitPolicy.GeometryRatio)
+
 
 # TODO:
 # - fetch rect: feat with changed geometry: 1. in rect, 2. out of rect