Read available provider fields for expression dialog from wfs Describ…

…eFeatureInfo

src/providers/wfs/qgswfsconnection.cpp

@@ -36,12 +36,17 @@ QgsWFSConnection::QgsWFSConnection( QString connName, QObject *parent ) :
   }
 }
 
-QString QgsWFSConnection::uriGetCapabilities()
+QString QgsWFSConnection::uriGetCapabilities() const
 {
   return mUri + "SERVICE=WFS&REQUEST=GetCapabilities&VERSION=1.0.0";
 }
 
-QString QgsWFSConnection::uriGetFeature( QString typeName, QString crsString, QString filter, QgsRectangle bBox )
+QString QgsWFSConnection::uriDescribeFeatureType( const QString& typeName ) const
+{
+  return mUri + "SERVICE=WFS&REQUEST=DescribeFeatureType&VERSION=1.0.0&TYPENAME=" + typeName;
+}
+
+QString QgsWFSConnection::uriGetFeature( QString typeName, QString crsString, QString filter, QgsRectangle bBox ) const
 {
   //get CRS
   if ( !crsString.isEmpty() )

src/providers/wfs/qgswfsconnection.h

@@ -21,14 +21,16 @@ class QgsWFSConnection : public QObject
     static void setSelectedConnection( QString name );
 
     //! base service URI
-    QString uri() { return mUri; }
+    QString uri() const { return mUri; }
     //! URI to get capabilities
-    QString uriGetCapabilities();
+    QString uriGetCapabilities() const;
+    //! URI to get schema of wfs layer
+    QString uriDescribeFeatureType( const QString& typeName ) const;
     //! URI to get features
     QString uriGetFeature( QString typeName,
                            QString crs = QString(),
                            QString filter = QString(),
-                           QgsRectangle bBox = QgsRectangle() );
+                           QgsRectangle bBox = QgsRectangle() ) const;
 
     //! start network connection to get capabilities
     void requestCapabilities();

src/providers/wfs/qgswfsprovider.cpp

@@ -47,12 +47,19 @@ static const QString GML_NAMESPACE = "http://www.opengis.net/gml";
 QgsWFSProvider::QgsWFSProvider( const QString& uri )
     : QgsVectorDataProvider( uri ),
     mNetworkRequestFinished( true ),
+    mEncoding( QgsWFSProvider::GET ),
     mUseIntersect( false ),
     mSourceCRS( 0 ),
     mFeatureCount( 0 ),
     mValid( true )
 {
   mSpatialIndex = 0;
+  if ( uri.isEmpty() )
+  {
+    mValid = false;
+    return;
+  }
+
   reloadData();
   if ( mValid )
   {

src/providers/wfs/qgswfsprovider.h

@@ -140,6 +140,9 @@ class QgsWFSProvider: public QgsVectorDataProvider
       synchronize with changes in the data source*/
     virtual void reloadData();
 
+    /**Collects information about the field types. Is called internally from QgsWFSProvider::getFeature. The method delegates the work to request specific ones and gives back the name of the geometry attribute and the thematic attributes with their types*/
+    int describeFeatureType( const QString& uri, QString& geometryAttribute, QgsFieldMap& fields );
+
   signals:
     void dataReadProgressMessage( QString message );
 
@@ -189,10 +192,6 @@ class QgsWFSProvider: public QgsVectorDataProvider
     /**Server capabilities for this layer (generated from capabilities document)*/
     int mCapabilities;
 
-
-    /**Collects information about the field types. Is called internally from QgsWFSProvider::getFeature. The method delegates the work to request specific ones and gives back the name of the geometry attribute and the thematic attributes with their types*/
-    int describeFeatureType( const QString& uri, QString& geometryAttribute, QgsFieldMap& fields );
-
     //encoding specific methods of getFeature
     int getFeatureGET( const QString& uri, const QString& geometryAttribute );
     int getFeaturePOST( const QString& uri, const QString& geometryAttribute );

src/providers/wfs/qgswfssourceselect.cpp

@@ -18,8 +18,10 @@
 #include "qgisinterface.h"
 #include "qgswfssourceselect.h"
 #include "qgswfsconnection.h"
+#include "qgswfsprovider.h"
 #include "qgsnewhttpconnection.h"
 #include "qgsgenericprojectionselector.h"
+#include "qgsexpressionbuilderdialog.h"
 #include "qgscontexthelp.h"
 #include "qgsproject.h"
 #include "qgscoordinatereferencesystem.h"
@@ -279,7 +281,7 @@ void QgsWFSSourceSelect::addLayer()
   {
     QString typeName = ( *sIt )->text( 1 );
     QString crs = labelCoordRefSys->text();
-    QString filter = mFilterLineEdit->text();
+    QString filter = ( *sIt )->text( 3 );
 
     //add a wfs layer to the map
     QgsWFSConnection conn( cmbConnections->currentText() );
@@ -364,3 +366,43 @@ void QgsWFSSourceSelect::on_btnLoad_clicked()
   populateConnectionList();
   emit connectionsChanged();
 }
+
+void QgsWFSSourceSelect::on_treeWidget_itemDoubleClicked( QTreeWidgetItem* item, int column )
+{
+  if ( item && column == 3 )
+  {
+    //get available fields for wfs layer
+    QgsWFSProvider p( "" );
+    QgsWFSConnection conn( cmbConnections->currentText() );
+    QString uri = conn.uriDescribeFeatureType( item->text( 1 ) );
+
+    QgsFieldMap fields;
+    QString geometryAttribute;
+    if ( p.describeFeatureType( uri, geometryAttribute, fields ) != 0 )
+    {
+      return;
+    }
+
+
+    //show expression builder
+    QgsExpressionBuilderDialog d( 0, item->text( 3 ) );
+
+    //add available attributes to expression builder
+    QgsExpressionBuilderWidget* w = d.expressionBuilder();
+    if ( !w )
+    {
+      return;
+    }
+
+    QgsFieldMap::const_iterator fieldIt = fields.constBegin();
+    for ( ; fieldIt != fields.constEnd(); ++fieldIt )
+    {
+      w->registerItem( tr( "Fields" ), fieldIt->name(), " " + fieldIt->name() + " ", "", QgsExpressionItem::Field );
+    }
+
+    if ( d.exec() == QDialog::Accepted )
+    {
+      item->setText( 3, w->getExpressionString() );
+    }
+  }
+}

src/providers/wfs/qgswfssourceselect.h

@@ -68,6 +68,7 @@ class QgsWFSSourceSelect: public QDialog, private Ui::QgsWFSSourceSelectBase
     void capabilitiesReplyFinished();
     void on_btnSave_clicked();
     void on_btnLoad_clicked();
+    void on_treeWidget_itemDoubleClicked( QTreeWidgetItem* item, int column );
 
     void on_buttonBox_helpRequested() { QgsContextHelp::run( metaObject()->className() ); }
 };

src/ui/qgswfssourceselectbase.ui

@@ -112,7 +112,7 @@
       <bool>true</bool>
      </property>
      <property name="columnCount">
-      <number>3</number>
+      <number>4</number>
      </property>
      <column>
       <property name="text">
@@ -129,6 +129,11 @@
        <string>Abstract</string>
       </property>
      </column>
+     <column>
+      <property name="text">
+       <string>Filter</string>
+      </property>
+     </column>
     </widget>
    </item>
    <item row="2" column="0">
@@ -180,27 +185,13 @@
     </widget>
    </item>
    <item row="3" column="0">
-    <layout class="QHBoxLayout" name="horizontalLayout_2">
-     <item>
-      <widget class="QLabel" name="mFilterStringLabel">
-       <property name="text">
-        <string>Filter</string>
-       </property>
-      </widget>
-     </item>
-     <item>
-      <widget class="QLineEdit" name="mFilterLineEdit"/>
-     </item>
-    </layout>
-   </item>
-   <item row="4" column="0">
     <widget class="QCheckBox" name="mBboxCheckBox">
      <property name="text">
       <string>Only request features overlapping the current view extent</string>
      </property>
     </widget>
    </item>
-   <item row="5" column="0">
+   <item row="4" column="0">
     <widget class="QDialogButtonBox" name="buttonBox">
      <property name="orientation">
       <enum>Qt::Horizontal</enum>