Make it so that returning Filter.EXCLUDE from ClientTransactionAccess…

…or.getUpdateFilter(String propName) means the filter referencing that property is not encodable to the backend

git-svn-id: http://svn.osgeo.org/geotools/trunk@38849 e5c1c795-43da-0310-a71f-fac65c449510

modules/library/main/src/main/java/org/geotools/filter/visitor/CapabilitiesFilterSplitter.java

@@ -126,12 +126,21 @@
  * say with certainty exactly how the logic for that part of this works, but the test suite does
  * seem to test it and the tests do pass.
  * </p>
+ * <p>
+ * Since GeoTools 8.0, the {@link ClientTransactionAccessor} interface can also be used to instruct
+ * the splitter that a filter referencing a given {@link PropertyName} can't be encoded by the
+ * back-end, by returning {@link Filter#EXCLUDE} in
+ * {@link ClientTransactionAccessor#getUpdateFilter(String) getUpdateFilter(String)}. This is so
+ * because there may be the case where some attribute names are encodable to the back-end's query
+ * language, while others may not be, or may not be part of the stored data model. In such case,
+ * returning {@code Filter.EXCLUDE} makes the filter referencing the property name part of the
+ * post-processing filter instead of the pre-processing filter.
  * 
  * @author dzwiers
  * @author commented and ported from gt to ogc filters by saul.farber
  * @author ported to work upon {@code org.geotools.filter.Capabilities} by Gabriel Roldan
- *
- *
+ * 
+ * 
  * @source $URL$
  * @since 2.5.3
  */
@@ -801,8 +810,13 @@ public Object visit(PropertyName expression, Object notUsed) {
             Filter updateFilter = (Filter) transactionAccessor.getUpdateFilter(expression
                     .getPropertyName());
             if (updateFilter != null) {
-                changedStack.add(updateFilter);
-                preStack.push(updateFilter);
+                if(updateFilter == Filter.EXCLUDE){
+                    // property name not encodable to backend
+                    postStack.push(expression);
+                }else{
+                    changedStack.add(updateFilter);
+                    preStack.push(updateFilter);
+                }
             } else
                 preStack.push(expression);
         } else {

modules/library/main/src/main/java/org/geotools/filter/visitor/ClientTransactionAccessor.java

@@ -43,7 +43,10 @@ public interface ClientTransactionAccessor {
 	 * Returns all the filters of updates that affect the attribute in the expression ORed together.
 	 * 
 	 * @param attributePath the xpath identifier of the attribute.
-	 * @return all the filters of updates that affect the attribute in the expression ORed together.
+	 * @return all the filters of updates that affect the attribute in the expression ORed together, 
+	 * {@link Filter#EXCLUDE} if the attribute path is not supported/encodable to the backend 
+	 * (and hence any filter including it shall only be evaluated at runtime), or {@code null} if no behavior
+	 * change is to be applied.
 	 */
 	Filter getUpdateFilter(String attributePath);