Actually, Field.setValue
does in fact return a reference to the field (docs), so you should be able to call setDisabled
(inherited from Component) as you have it. You must have some other issue going on. Maybe findField('start_date')
is returning null. You have to make sure all the return values are what you expect. Use Firebug to figure out the error, or break apart your statement and see which call is actually failing.
Anything is "chainable" as long as the return value is the object itself (usually denoted as this
in the docs). In jQuery, everything operates on DOM elements, so it is consistent. In Ext, you have lots of components with various behaviors. Sometimes chaining makes sense, sometimes it does not -- just make sure you check the docs when you aren't sure.