value patterns for attributes

xml/openapi/src/com/intellij/patterns/XmlAttributeValuePattern.java

@@ -66,4 +66,13 @@ public class XmlAttributeValuePattern extends XmlElementPattern<XmlAttributeValu
     });
   }
 
+  public XmlAttributeValuePattern withValue(final StringPattern valuePattern) {
+    return with(new PatternCondition<XmlAttributeValue>("withValue") {
+      @Override
+      public boolean accepts(@NotNull XmlAttributeValue xmlAttributeValue, ProcessingContext context) {
+        return valuePattern.accepts(xmlAttributeValue.getValue(), context);
+      }
+    });
+  }
+
 }

xml/openapi/src/com/intellij/patterns/XmlNamedElementPattern.java

@@ -75,6 +75,15 @@ public abstract class XmlNamedElementPattern<T extends XmlElement & PsiNamedElem
     protected String getNamespace(XmlAttribute xmlAttribute) {
       return xmlAttribute.getNamespace();
     }
+    
+    public XmlAttributePattern withValue(final StringPattern pattern) {
+      return with(new PatternCondition<XmlAttribute>("withValue") {
+        @Override
+        public boolean accepts(@NotNull XmlAttribute xmlAttribute, ProcessingContext context) {
+          return pattern.accepts(xmlAttribute.getValue(), context);
+        }
+      });
+    }
 
   }