diff -r af170d42b5b3 -r 22358b42ec2a javaquery/api/src/main/java/org/apidesign/bck2brwsr/htmlpage/ConvertTypes.java
--- a/javaquery/api/src/main/java/org/apidesign/bck2brwsr/htmlpage/ConvertTypes.java	Mon Mar 25 11:50:36 2013 +0100
+++ b/javaquery/api/src/main/java/org/apidesign/bck2brwsr/htmlpage/ConvertTypes.java	Sun Mar 31 05:34:15 2013 +0200
@@ -41,6 +41,14 @@
         Object ret = getProperty(object, property);
         return ret instanceof Number ? ((Number)ret).intValue() : Integer.MIN_VALUE;
     }
+
+    public static <T> T toModel(Class<T> modelClass, Object object, String property) {
+        Object ret = getProperty(object, property);
+        if (ret == null || modelClass.isInstance(ret)) {
+            return modelClass.cast(ret);
+        }
+        throw new IllegalStateException("Value " + ret + " is not of type " + modelClass);
+    }
     
     @JavaScriptBody(args = { "object", "property" },
         body = "if (property === null) return object;\n"