Hi Leo,

These two questions are really ext-specific and I would encourage you to check out Ext's documentation and forums. The template I describe is a config option available with Ext comboboxes which allows you to define a custom template (ie. the code behind how that HTML is generated) for each item in the drop-down menu. templates are quite useful, but you need to be careful when overriding Ext's default templates. If you want to learn about them, I encourage you to read the following:

http://docs.sencha.com/ext-js/3-4/#!/api/Ext.Template

http://docs.sencha.com/ext-js/3-4/#!/api/Ext.DataView

The latter is probably the most appropriate place to learn to use them.

To learn more about plugins, I also encourage you to check out Ext's doc. In this instance, we created a plugin to customize the Ext combobox. This particular plugin is predominantly used to auto-size the width of the pick-list. While plugins are sometimes the appropriate mechanism, it's far more common that subclassing an Ext component is going to get you what you need.