OGC filter export: support for basic comparison operators, literal an…

…d propertyName
qgis · Dec 7, 2011 · b72f086 · b72f086
1 parent 0f74e07
commit b72f086
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Showing 3 changed files with 92 additions and 7 deletions.
diff --git a/src/core/qgsexpression.cpp b/src/core/qgsexpression.cpp
@@ -16,6 +16,7 @@
 #include "qgsexpression.h"
 
 #include <QtDebug>
+#include <QDomDocument>
 #include <QSettings>
 #include <math.h>
 
@@ -968,3 +969,74 @@ QString QgsExpression::NodeColumnRef::dump() const
 {
   return mName;
 }
+
+bool QgsExpression::toOGCFilter( QDomDocument& doc ) const
+{
+  if ( !mRootNode )
+  {
+    return false;
+  }
+
+  doc.clear();
+  QDomElement filterElem = doc.createElementNS( "http://www.opengis.net/fes/2.0", "Filter" );
+  doc.appendChild( filterElem );
+  return mRootNode->toOGCFilter( doc, filterElem );
+}
+
+bool QgsExpression::NodeBinaryOperator::toOGCFilter( QDomDocument& doc, QDomElement& parent ) const
+{
+  QDomElement opElem;
+  switch ( mOp )
+  {
+    case boEQ:
+      opElem = doc.createElement( "PropertyIsEqualTo" );
+      break;
+    case boNE:
+      opElem = doc.createElement( "PropertyIsNotEqualTo" );
+      break;
+    case boLE:
+      opElem = doc.createElement( "PropertyIsLessThanOrEqualTo" );
+      break;
+    case boGE:
+      opElem = doc.createElement( "PropertyIsLessThanOrEqualTo" );
+      break;
+    case boLT:
+      opElem = doc.createElement( "PropertyIsLessThan" );
+      break;
+    case boGT:
+      opElem = doc.createElement( "PropertyIsGreaterThan" );
+      break;
+    default:
+      return false;
+  }
+
+  if ( mOpLeft )
+  {
+    mOpLeft->toOGCFilter( doc, opElem );
+  }
+  if ( mOpRight )
+  {
+    mOpRight->toOGCFilter( doc, opElem );
+  }
+
+  parent.appendChild( opElem );
+  return true;
+}
+
+bool QgsExpression::NodeLiteral::toOGCFilter( QDomDocument& doc, QDomElement& parent ) const
+{
+  QDomElement literalElem = doc.createElement( "Literal" );
+  QDomText literalText = doc.createTextNode( mValue.toString() );
+  literalElem.appendChild( literalText );
+  parent.appendChild( literalElem );
+  return true;
+}
+
+bool QgsExpression::NodeColumnRef::toOGCFilter( QDomDocument& doc, QDomElement& parent ) const
+{
+  QDomElement propertyElem = doc.createElement( "PropertyName" );
+  QDomText propertyText = doc.createTextNode( mName );
+  propertyElem.appendChild( propertyText );
+  parent.appendChild( propertyElem );
+  return true;
+}
diff --git a/src/core/qgsexpression.h b/src/core/qgsexpression.h
@@ -24,6 +24,8 @@
 
 class QgsDistanceArea;
 class QgsFeature;
+class QDomDocument;
+class QDomElement;
 
 /**
 Class for parsing and evaluation of expressions (formerly called "search strings").
@@ -120,6 +122,9 @@ class CORE_EXPORT QgsExpression
 
     //! Return the parsed expression as a string - useful for debugging
     QString dump() const;
+    //! Creates ogc filter xml document
+    //! @return true in case of success
+    bool toOGCFilter( QDomDocument& doc ) const;
 
     //! Return calculator used for distance and area calculations
     //! (used by internal functions)
@@ -222,6 +227,7 @@ class CORE_EXPORT QgsExpression
 
         virtual QStringList referencedColumns() const = 0;
         virtual bool needsGeometry() const = 0;
+        virtual bool toOGCFilter( QDomDocument& doc, QDomElement& parent ) const { return false; }
     };
 
     class NodeList
@@ -265,6 +271,8 @@ class CORE_EXPORT QgsExpression
         virtual QString dump() const;
         virtual QStringList referencedColumns() const { return mOpLeft->referencedColumns() + mOpRight->referencedColumns(); }
         virtual bool needsGeometry() const { return mOpLeft->needsGeometry() || mOpRight->needsGeometry(); }
+        virtual bool toOGCFilter( QDomDocument& doc, QDomElement& parent ) const;
+
       protected:
         bool compare( double diff );
         int computeInt( int x, int y );
@@ -320,6 +328,7 @@ class CORE_EXPORT QgsExpression
         virtual QString dump() const;
         virtual QStringList referencedColumns() const { return QStringList(); }
         virtual bool needsGeometry() const { return false; }
+        virtual bool toOGCFilter( QDomDocument& doc, QDomElement& parent ) const;
       protected:
         QVariant mValue;
     };
@@ -334,6 +343,7 @@ class CORE_EXPORT QgsExpression
         virtual QString dump() const;
         virtual QStringList referencedColumns() const { return QStringList( mName ); }
         virtual bool needsGeometry() const { return false; }
+        virtual bool toOGCFilter( QDomDocument& doc, QDomElement& parent ) const;
       protected:
         QString mName;
         int mIndex;

diff --git a/src/providers/wfs/qgswfsconnection.cpp b/src/providers/wfs/qgswfsconnection.cpp
@@ -1,14 +1,12 @@
 #include "qgswfsconnection.h"
-
+#include "qgsexpression.h"
 #include "qgslogger.h"
-
-#include <QDomDocument>
-#include <QSettings>
-#include <QStringList>
-
 #include "qgsnetworkaccessmanager.h"
+#include <QDomDocument>
 #include <QNetworkRequest>
 #include <QNetworkReply>
+#include <QSettings>
+#include <QStringList>
 
 static const QString WFS_NAMESPACE = "http://www.opengis.net/wfs";
 
@@ -57,7 +55,12 @@ QString QgsWFSConnection::uriGetFeature( QString typeName, QString crsString, QS
   QString filterString;
   if ( !filter.isEmpty() )
   {
-    filterString = "&FILTER=" + filter;
+    QgsExpression filterExpression( filter );
+    QDomDocument filterDoc;
+    if ( filterExpression.toOGCFilter( filterDoc ) )
+    {
+      filterString = "&FILTER=" + filterDoc.toString();
+    }
   }
 
   QString bBoxString;