This is an example of how I used the jQuery Automcomplete Widget with Rails 3.2 for a recipe search field. Some of the jQuery stuff mentioned below is included out of the box with a new Rails application.
- Make sure the jQuery gem is referenced in the Gemfile
- Download one of the jQuery-ui css files, or a custom one, and put it in one of you asset locations. I put mine in vendor/assets/stylesheets/jquery-ui-1.8.18.custom.css. Include the css file in app/assets/stylesheets/application.css
- Create a controller action to search and return values for the autocomplete dropdown menu. In my Recipes controller (you could also create a seperate Search controller), I created an Action to return a list of matching recipe titles as a json array. The search can also be applied to recipes in a single category, hence the category_id parameter.
- Add a route for the search_on_title action.
- The search form is just a normal form.
There’s also a Rails gem to make autocomplete easier, but I found this to be easy enough such that I didn’t have to depend on an additional plugin.