How to create custom ExtJS form field component?

Question

I want to create custom ExtJS form field components using other ExtJS components in it (e.g. TreePanel). How can I do it most easily?

I\'ve read doc

Answer 1

Many of the answers either use the Mixin Ext.form.field.Field or just extends on some already made class that suits their needs - which is fine.

But I do not recommend fully overwriting the setValue method, that is IMO really bad form!

A lot more happens than just setting and getting the value, and if you fully overwrite it - well you will for instance mess up the dirty state, processing of rawValue etc..

Two options here I guess, one is to callParent(arguments) inside the method you declare to keep things streamlined, or to at the end when you are done apply the inherited method from where ever you got it (mixin or extend).

But do not just overwrite it with no regards for what that already made method does behind the scenes.

Also remember that if you use other field types in your new class - then do set the isFormField property to false - otherwise your getValues method on the form will take those values and run with em!