问题
Hi I want to implement a drop-down for countries and states.The states drop-down should change its values according to the country selected. Is there any plugin or gem to do this in rails.
回答1:
Try the Carmen plugin:
http://autonomousmachine.com/posts/2009/4/1/carmen-a-rails-plugin-for-geographic-names-and-abbreviations
You can also check this other stackoverflow post:
Ruby on Rails Country/State Select Enigma
回答2:
Country State Select is a library that provides an easy API to generate Country and State / Province dropdowns for use in forms.
When implemented correctly, a State / Province dropdown is filled with appropriate regions based on what Country a user has selected.
After it's version 2.0.0 it also dependent to simple_form 3.2
you can also find cities according to the state and country name by using this gem
https://rubygems.org/gems/country_state_select
来源：https://stackoverflow.com/questions/6825564/drop-down-for-country-states