In the API documentation, there's reference to a 'Mixed' type, what does that refer to? Does that mean it can be a DOM ID, Dom Element or Ext object? Or something far more generic?
Yeah, so mixed means it could be a combination of the single types (like Boolean, String, Number, Array, Object, etc.). It depends on the API reference what is actually accepted. When you're not clear on it, I'd suggest opening the source code for that Class and inspecting it.