[Answer]-How to refer to extJS combobox using a string?

I don’t know if i understand right, but you want a specific combobox for your editor like xtype: 'combo'?

You can define a new xtype based on a combobox which can used as editor: 'data_type_combo.

Here is an example fiddle how you could achieve this: https://fiddle.sencha.com/#fiddle/nup