Fix for trac ticket #4. (Tested on DEMIS site.)

With the Identify tool on a WMS layer, now send a query to the WMS server *only* on those layers that the WMS server had already declared queryable.  This avoids the server returning an error on un-queryable layers.

Also, QgsWmsProvider::identifyAsHtml() is renamed to QgsWmsProvider::identifyAsText() to better identify what it does.  Commentary, and other dependent variable and function names have also been updated to suit.



git-svn-id: http://svn.osgeo.org/qgis/trunk@5606 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/core/qgsrasterdataprovider.h

@@ -138,15 +138,15 @@ class QgsRasterDataProvider : public QgsDataProvider
      *
      * \param point[in]  The pixel coordinate (as it was displayed locally on screen)
      *
-     * \retval  An HTML document containing the return from the WMS server
+     * \return  A text document containing the return from the WMS server
      *
      * \note WMS Servers prefer to receive coordinates in image space, therefore
      *       this function expects coordinates in that format.
      *
      * \note  The arbitraryness of the returned document is enforced by WMS standards
      *        up to at least v1.3.0
      */
-    virtual QString identifyAsHtml(const QgsPoint& point) = 0;
+    virtual QString identifyAsText(const QgsPoint& point) = 0;
 
     /**
      * \brief   Returns the caption error text for the last error in this provider

src/gui/qgsmaptoolidentify.cpp

@@ -157,9 +157,9 @@ void QgsMapToolIdentify::identifyRasterWmsLayer(QgsRasterLayer* layer, const Qgs
     return;
   }
 
-  QString html = layer->identifyAsHtml(point);
+  QString text = layer->identifyAsText(point);
 
-  if (html.isEmpty())
+  if (text.isEmpty())
   {
     showError(layer);
     return;
@@ -171,8 +171,7 @@ void QgsMapToolIdentify::identifyRasterWmsLayer(QgsRasterLayer* layer, const Qgs
   }
 
   mViewer->setCaption( layer->name() );
-  mViewer->setMessageAsPlainText( html );
-//  mViewer->setMessageAsHtml( html );
+  mViewer->setMessageAsPlainText( text );
 
 //  mViewer->exec();
   mViewer->show();

src/providers/wms/qgswmsprovider.cpp

@@ -2294,27 +2294,36 @@ QString QgsWmsProvider::getMetadata()
 }
 
 
-QString QgsWmsProvider::identifyAsHtml(const QgsPoint& point)
+QString QgsWmsProvider::identifyAsText(const QgsPoint& point)
 {
 #ifdef QGISDEBUG
-  std::cout << "QgsWmsProvider::identifyAsHtml: entering." << std::endl;
+  std::cout << "QgsWmsProvider::identifyAsText: entering." << std::endl;
 #endif
 
   // Collect which layers to query on
 
-  QStringList visibleLayers = QStringList();
+  QStringList queryableLayers = QStringList();
 
-  for ( QStringList::Iterator it  = activeSubLayers.begin(); 
-                              it != activeSubLayers.end(); 
-                            ++it ) 
+  // Test for which layers are suitable for querying with
+  for ( QStringList::const_iterator it  = activeSubLayers.begin(); 
+                                    it != activeSubLayers.end(); 
+                                  ++it )
   {
+    // Is sublayer visible?
     if (TRUE == activeSubLayerVisibility.find( *it )->second)
     {
-      visibleLayers += *it;
+      // Is sublayer queryable?
+      if (TRUE == mQueryableForLayer.find( *it )->second)
+      {
+#ifdef QGISDEBUG
+  std::cout << "QgsWmsProvider::identifyAsText: '" << (*it).toLocal8Bit().data() << "' is queryable." << std::endl;
+#endif
+        queryableLayers += *it;
+      }
     }
   }
 
-  QString layers = visibleLayers.join(",");
+  QString layers = queryableLayers.join(",");
   Q3Url::encode( layers );
 
   // Compose request to WMS server
@@ -2343,18 +2352,13 @@ QString QgsWmsProvider::identifyAsHtml(const QgsPoint& point)
   requestUrl += QString( "Y=%1" )
                    .arg( point.y() );
 
-  QString html = retrieveUrl(requestUrl);
-
-  if (html.isEmpty())
-  {
-    return QString();
-  }
+  QString text = retrieveUrl(requestUrl);
 
 #ifdef QGISDEBUG
-  std::cout << "QgsWmsProvider::identifyAsHtml: exiting with '"
-            << html.toLocal8Bit().data() << "'." << std::endl;
+  std::cout << "QgsWmsProvider::identifyAsText: exiting with '"
+            << text.toLocal8Bit().data() << "'." << std::endl;
 #endif
-  return html;
+  return text;
 }
 
 

src/providers/wms/qgswmsprovider.h

@@ -528,15 +528,15 @@ class QgsWmsProvider : public QgsRasterDataProvider
    *
    * \param point[in]  The pixel coordinate (as it was displayed locally on screen)
    *
-   * \retval  An HTML document containing the return from the WMS server
+   * \return  A text document containing the return from the WMS server
    *
    * \note WMS Servers prefer to receive coordinates in image space, therefore
    *       this function expects coordinates in that format.
    *
    * \note  The arbitraryness of the returned document is enforced by WMS standards
    *        up to at least v1.3.0
    */
-  QString identifyAsHtml(const QgsPoint& point);
+  QString identifyAsText(const QgsPoint& point);
 
   /**
    * \brief   Returns the caption error text for the last error in this provider

src/raster/qgsrasterlayer.cpp

@@ -4827,15 +4827,15 @@ void QgsRasterLayer::identify(const QgsPoint& point, std::map<QString,QString>&
 } // void QgsRasterLayer::identify
 
 
-QString QgsRasterLayer::identifyAsHtml(const QgsPoint& point)
+QString QgsRasterLayer::identifyAsText(const QgsPoint& point)
 {
   if (mProviderKey != "wms")
   {
     // Currently no meaning for anything other than OGC WMS layers
     return QString();
   }
 
-  return (dataProvider->identifyAsHtml(point));
+  return (dataProvider->identifyAsText(point));
 }
 
 void QgsRasterLayer::populateHistogram(int theBandNoInt, int theBinCountInt,bool theIgnoreOutOfRangeFlag,bool theHistogramEstimatedFlag)

src/raster/qgsrasterlayer.h

@@ -285,12 +285,12 @@ class QgsRasterLayer : public QgsMapLayer
      *
      * \param point[in]  an image pixel coordinate in the last requested extent of layer.
      *
-     * \retval  An HTML document containing the return from the WMS server
+     * \return  A text document containing the return from the WMS server
      *
      * \note  The arbitraryness of the returned document is enforced by WMS standards
      *        up to at least v1.3.0
      */
-    QString identifyAsHtml(const QgsPoint& point);
+    QString identifyAsText(const QgsPoint& point);
 
     /** \brief Query gdal to find out the WKT projection string for this layer. This implements the virtual method of the same name defined in QgsMapLayer*/
     QString getProjectionWKT();