Forms are very well supported in Ruby on Rails. But in some cases you want to get information about a value a user has entered in a form, but without submitting the entire form. A good example of this is the sign up procedure at Yahoo. You enter your desired username, click “check availability” and you know if the name is available to you.
In my case I want to add locations to my database and use geocoding to get latituden/longitude values. So, I want users to enter an address and click “check” to verify that geocoding is successful. When successful, the full address and lat/lng values are automatically filled out in the form.
This article shows you how to update those text fields and most importantly, it shows how to add a text_field value as a paramater to your link_to_remote tag.