GWT: “For security purposes, this type will not be serialized.”

The full error message you can get is: “Foo was not included in the set of types which can be serialized by this SerializationPolicy or its Class object could not be loaded. For security purposes, this type will not be serialized.”

This is normally caused by using a non-serializable class, which can happen if your class does not implement serializable or if you have forgotten to add a empty constructor.

EXT GWT: Adding onClick to Labels

I had a issue where i needed to add a click handler for labels in EXT GWT, the solution i came up with was as follows

theLabel.addListener(Events.OnClick, new Listener() {
@Override
public void handleEvent(BaseEvent be) {
    // TODO Auto-generated method stub
}});