[dualview] Default preview text shows also up for NULL values

m-kuhn · m-kuhn · commit a10598733e94 · 2013-09-02T20:19:47.000+02:00
diff --git a/src/gui/attributetable/qgsdualview.cpp b/src/gui/attributetable/qgsdualview.cpp
@@ -80,13 +80,19 @@ void QgsDualView::columnBoxInit()
   // load fields
   QList<QgsField> fields = mLayerCache->layer()->pendingFields().toList();
 
+  QString defaultField;
+
   // default expression: saved value
   QString displayExpression = mLayerCache->layer()->displayExpression();
 
   // if no display expression is saved: use display field instead
   if ( displayExpression == "" )
   {
-    displayExpression = mLayerCache->layer()->displayField();
+    if ( mLayerCache->layer()->displayField() != "" )
+    {
+      defaultField = mLayerCache->layer()->displayField();
+      displayExpression = QString( "COALESCE(\"%1\", '<NULL>')" ).arg( defaultField );
+    }
   }
 
   // if neither diaplay expression nor display field is saved...
@@ -96,31 +102,37 @@ void QgsDualView::columnBoxInit()
 
     if ( pkAttrs.size() > 0 )
     {
+      if ( pkAttrs.size() == 1 )
+        defaultField = pkAttrs.at( 0 );
+
       // ... If there are primary key(s) defined
       QStringList pkFields;
 
-      foreach ( int attr, pkAttrs )
+      Q_FOREACH( int attr, pkAttrs )
       {
-        pkFields.append( "\"" + fields[attr].name() + "\"" );
+        pkFields.append( "COALESCE(\"" + fields[attr].name() + "\", '<NULL>')" );
       }
 
       displayExpression = pkFields.join( "||', '||" );
     }
     else if ( fields.size() > 0 )
     {
+      if ( fields.size() == 1 )
+        defaultField = fields.at( 0 ).name();
+
       // ... concat all fields
       QStringList fieldNames;
       foreach ( QgsField field, fields )
       {
-        fieldNames.append( "\"" + field.name() + "\"" );
+        fieldNames.append( "COALESCE(\"" + field.name() + "\", '<NULL>')" );
       }
 
       displayExpression = fieldNames.join( "||', '||" );
     }
     else
     {
       // ... there isn't really much to display
-      displayExpression = "[Please define preview text]";
+      displayExpression = "'[Please define preview text]'";
     }
   }
 
@@ -151,7 +163,7 @@ void QgsDualView::columnBoxInit()
       connect( previewAction, SIGNAL( triggered() ), mPreviewActionMapper, SLOT( map() ) );
       mPreviewColumnsMenu->addAction( previewAction );
 
-      if ( text == displayExpression )
+      if ( text == defaultField )
       {
         mFeatureListPreviewButton->setDefaultAction( previewAction );
       }
@@ -315,7 +327,7 @@ void QgsDualView::previewColumnChanged( QObject* action )
 
   if ( previewAction )
   {
-    if ( !mFeatureList->setDisplayExpression( previewAction->text() ) )
+    if ( !mFeatureList->setDisplayExpression( QString( "COALESCE( \"%1\", '<NULL>' )" ).arg( previewAction->text() ) ) )
     {
       QMessageBox::warning( this
                             , tr( "Could not set preview column" )

Original file line number	Diff line number	Diff line change
`@@ -80,13 +80,19 @@ void QgsDualView::columnBoxInit()`
`80`	`80`	`// load fields`
`81`	`81`	`QList<QgsField> fields = mLayerCache->layer()->pendingFields().toList();`
`82`	`82`
	`83`	`+ QString defaultField;`
	`84`	`+`
`83`	`85`	`// default expression: saved value`
`84`	`86`	`QString displayExpression = mLayerCache->layer()->displayExpression();`
`85`	`87`
`86`	`88`	`// if no display expression is saved: use display field instead`
`87`	`89`	`if ( displayExpression == "" )`
`88`	`90`	`{`
`89`		`- displayExpression = mLayerCache->layer()->displayField();`
	`91`	`+ if ( mLayerCache->layer()->displayField() != "" )`
	`92`	`+ {`
	`93`	`+ defaultField = mLayerCache->layer()->displayField();`
	`94`	`+ displayExpression = QString( "COALESCE(\"%1\", '<NULL>')" ).arg( defaultField );`
	`95`	`+ }`
`90`	`96`	`}`
`91`	`97`
`92`	`98`	`// if neither diaplay expression nor display field is saved...`
`@@ -96,31 +102,37 @@ void QgsDualView::columnBoxInit()`
`96`	`102`
`97`	`103`	`if ( pkAttrs.size() > 0 )`
`98`	`104`	`{`
	`105`	`+ if ( pkAttrs.size() == 1 )`
	`106`	`+ defaultField = pkAttrs.at( 0 );`
	`107`	`+`
`99`	`108`	`// ... If there are primary key(s) defined`
`100`	`109`	`QStringList pkFields;`
`101`	`110`
`102`		`- foreach ( int attr, pkAttrs )`
	`111`	`+ Q_FOREACH( int attr, pkAttrs )`
`103`	`112`	`{`
`104`		`- pkFields.append( "\"" + fields[attr].name() + "\"" );`
	`113`	`+ pkFields.append( "COALESCE(\"" + fields[attr].name() + "\", '<NULL>')" );`
`105`	`114`	`}`
`106`	`115`
`107`	`116`	`displayExpression = pkFields.join( "\|\|', '\|\|" );`
`108`	`117`	`}`
`109`	`118`	`else if ( fields.size() > 0 )`
`110`	`119`	`{`
	`120`	`+ if ( fields.size() == 1 )`
	`121`	`+ defaultField = fields.at( 0 ).name();`
	`122`	`+`
`111`	`123`	`// ... concat all fields`
`112`	`124`	`QStringList fieldNames;`
`113`	`125`	`foreach ( QgsField field, fields )`
`114`	`126`	`{`
`115`		`- fieldNames.append( "\"" + field.name() + "\"" );`
	`127`	`+ fieldNames.append( "COALESCE(\"" + field.name() + "\", '<NULL>')" );`
`116`	`128`	`}`
`117`	`129`
`118`	`130`	`displayExpression = fieldNames.join( "\|\|', '\|\|" );`
`119`	`131`	`}`
`120`	`132`	`else`
`121`	`133`	`{`
`122`	`134`	`// ... there isn't really much to display`
`123`		`- displayExpression = "[Please define preview text]";`
	`135`	`+ displayExpression = "'[Please define preview text]'";`
`124`	`136`	`}`
`125`	`137`	`}`
`126`	`138`
`@@ -151,7 +163,7 @@ void QgsDualView::columnBoxInit()`
`151`	`163`	`connect( previewAction, SIGNAL( triggered() ), mPreviewActionMapper, SLOT( map() ) );`
`152`	`164`	`mPreviewColumnsMenu->addAction( previewAction );`
`153`	`165`
`154`		`- if ( text == displayExpression )`
	`166`	`+ if ( text == defaultField )`
`155`	`167`	`{`
`156`	`168`	`mFeatureListPreviewButton->setDefaultAction( previewAction );`
`157`	`169`	`}`
`@@ -315,7 +327,7 @@ void QgsDualView::previewColumnChanged( QObject* action )`
`315`	`327`
`316`	`328`	`if ( previewAction )`
`317`	`329`	`{`
`318`		`- if ( !mFeatureList->setDisplayExpression( previewAction->text() ) )`
	`330`	`+ if ( !mFeatureList->setDisplayExpression( QString( "COALESCE( \"%1\", '<NULL>' )" ).arg( previewAction->text() ) ) )`
`319`	`331`	`{`
`320`	`332`	`QMessageBox::warning( this`
`321`	`333`	`, tr( "Could not set preview column" )`