Sometime ago I used carmen-rails and liked the project, but it's not maintained anymore. I also felt that it was not very magical and some simple spells could make it more sexy!

gem 'cs-rails'

I only used with Simple Form and didn't write any test, so no country_select_tag for now, you must have a FormBuilder to use it.

First, you have to mount cs-rails engine: mount CsRails::Engine, at: '/cs'

Add the country select with/without priority countries.

= f_address.input :country, priority: ['BR', 'AR', 'CL', 'PY', 'UY'], input_html: { data: { cs_rails: true } }

You have to #= require cs-rails/countries. It will find any country input with data-cs-rails attribute and submit an ajax request to find the states for the selected country. If the states aren't find for the country, the state select is replaced by an input, so the user can write the state.

It will replace the contents for any select/input that have an id ending with "_state". If you want to control the select/input that must be replaced you use the state-input-id data attribute as following:

= f_address.input :country, priority: ['BR', 'AR', 'CL', 'PY', 'UY'], input_html: { data: { cs_rails: true, state_input_id: 'target_input_id' } }

Sometimes you need to set the country input data with $('#country_input_id').val(some_var), in these cases you need to trigger a 'change' event and you can pass a callback to execute after the states load:

$('select[id$=country]').val(some_var).trigger('change', fillState)

For now, it's all!

This project rocks and uses MIT-LICENSE.