Disable click to open and get the desired format from the rules.

Frameworks/Core/ERDirectToWeb/Sources/er/directtoweb/pages/ERD2WGraphVizPage.java

@@ -32,6 +32,11 @@ public class ERD2WGraphVizPage extends ERD2WPage {
 	 */
 	private static final long serialVersionUID = 1L;
 
+    /** interface for all the keys used in this pages code */
+    public interface Keys extends ERD2WPage.Keys {
+	    public static String format = "format";
+	}
+
     private int _nodeID = 0;
 
     public ERD2WGraphVizPage(WOContext context) {
@@ -83,14 +88,24 @@ public NSArray<String> toManyRelationships() {
         return result;
     }
 
+    /* 
+     * Disable click to open
+     */
+    public boolean clickToOpenEnabled(WOResponse response, WOContext context) {
+        return false;
+    }
+
     @Override
     public void appendToResponse(WOResponse response, WOContext context) {
         // we do NOT want to expose our model to just everyone...
         if (ERXApplication.isDevelopmentModeSafe()) {
             super.appendToResponse(response, context);
         }
         response.setHeader("text/plain", "content-type");
-        String format = context.request().stringFormValueForKey("format");
+        String format = (String) d2wContext().valueForKey(Keys.format);
+        if (format == null) {
+            format = context.request().stringFormValueForKey("format");
+        }
         if (format != null) {
             String dot = response.contentString();
             File f = null;