Now if you need to search more than one field in the same field, you can by passing the :columns_names this way:

autocomplete :company, :name, :columns_names=>[:name, :phone]

Now works with mongoid.

rails3-jquery-autocomplete

An easy way to use jQuery's autocomplete with Rails 3.

Supports both ActiveRecord, mongoid, and MongoMapper.

Works with Formtastic and SimpleForm

ActiveRecord

You can find a detailed example on how to use this gem with ActiveRecord here.

MongoID

You can find a detailed example on how to use this gem with MongoID here. (Same thing, different branch)

Before you start

Make sure your project is using jQuery-UI and the autocomplete widget before you continue.

You can find more info about that here:

• http://jquery.com/
• http://jqueryui.com/demos/autocomplete/
• http://github.com/rails/jquery-ujs

I'd encourage you to understand how to use those 3 amazing tools before attempting to use this gem.

Installing

Include the gem on your Gemfile

gem 'rails3-jquery-autocomplete'

Install it

bundle install

Rails 3.0.x

Run the generator

rails generate autocomplete:install

And include autocomplete-rails.js on your layouts

javascript_include_tag "autocomplete-rails.js"

Upgrading from older versions

If you are upgrading from a previous version, run the generator after installing to replace the javascript file.

rails generate autocomplete:install

I'd recommend you do this every time you update to make sure you have the latest JS file.

Uncompressed Javascript file

If you want to make changes to the JS file, you can install the uncompressed version by running:

rails generate autocomplete:uncompressed

Rails 3.1.x

Just add it to your app/assets/javascripts/application.js file

//= require jquery
//= require jquery_ujs
//= require jquery-ui
//= require autocomplete-rails

Usage

Model Example

Assuming you have a Brand model:

class Brand < ActiveRecord::Base
end

create_table :brand do |t|
  t.column :name, :string
end

Controller

To set up the required action on your controller, all you have to do is call it with the class name and the method as in the following example:

class ProductsController < Admin::BaseController
  autocomplete :brand, :name
end

This will create an action autocomplete_brand_name on your controller, don't forget to add it on your routes file

resources :products do
  get :autocomplete_brand_name, :on => :collection
end

Options

:full => true

By default, the search starts from the beginning of the string you're searching for. If you want to do a full search, set the full parameter to true.

class ProductsController < Admin::BaseController
  autocomplete :brand, :name, :full => true
end

The following terms would match the query 'un':

• Luna
• Unacceptable
• Rerun

:full => false (default behavior)

Only the following terms mould match the query 'un':

• Unacceptable

:extra_data

By default, your search will only return the required columns from the database needed to populate your form, namely id and the column you are searching (name, in the above example).

Passing an array of attributes/column names to this option will fetch and return the specified data.

class ProductsController < Admin::BaseController
  autocomplete :brand, :name, :extra_data => [:slogan]
end

:display_value

If you want to display a different version of what you're looking for, you can use the :display_value option.

This options receives a method name as the parameter, and that method will be called on the instance when displaying the results.

class Brand < ActiveRecord::Base
  def funky_method
    "#{self.name}.camelize"
  end
end


class ProductsController < Admin::BaseController
  autocomplete :brand, :name, :display_value => :funky_method
end

In the example above, you will search by name, but the autocomplete list will display the result of funky_method

This wouldn't really make much sense unless you use it with the "id_element" attribute. (See below)

Only the object's id and the column you are searching on will be returned in JSON, so if your display_value method requires another parameter, make sure to fetch it with the :extra_data option

:scopes

Added option to use scopes. Pass scopes in an array. e.g :scopes => [:scope1, :scope2]

:column_name

By default autocomplete uses method name as column name. Now it can be specified using column_name options :column_name => 'name'

json encoder

Autocomplete uses Yajl as JSON encoder/decoder, but you can specify your own

class ProductsController < Admin::BaseController
  autocomplete :brand, :name do |items|
     CustomJSON::Encoder.encode(items)
  end
end

View

On your view, all you have to do is include the attribute autocomplete on the text field using the url to the autocomplete action as the value.

form_for @product do |f|
  f.autocomplete_field :brand_name, autocomplete_brand_name_products_path
end

This will generate an HTML tag that looks like:

<input type="text" data-autocomplete="products/autocomplete_brand_name">

If you are not using a FormBuilder (form_for) or you just want to include an autocomplete field without the form, you can use the autocomplete_field_tag helper.

form_tag 'some/path'
  autocomplete_field_tag 'address', '', address_autocomplete_path, :size => 75
end

Now your autocomplete code is unobtrusive, Rails 3 style.

Getting the object id

If you need to use the id of the selected object, you can use the id_element attribute too:

f.autocomplete_field :brand_name, autocomplete_brand_name_products_path, :id_element => '#some_element'

This will update the field with id *#some_element with the id of the selected object. The value for this option can be any jQuery selector.

Getting extra object data

If you need to extra data about the selected object, you can use the :update_elements HTML attribute.

The :update_elements attribute accepts a hash where the keys represent the object attribute/column data to use to update and the values are jQuery selectors to retrieve the HTML element to update:

f.autocomplete_field :brand_name, autocomplete_brand_name_products_path, :update_elements => {:id => '#id_element', :slogan => '#some_other_element'}

class ProductsController < Admin::BaseController
  autocomplete :brand, :name, :extra_data => [:slogan]
end

The previous example would fetch the extra attribute slogan and update jQuery('#some_other_element') with the slogan value.

Running custom code on selection

A javascript event named railsAutocomplete.select is fired on the input field when a value is selected from the autocomplete drop down. If you need to do something more complex than update fields with data, you can hook into this event, like so:

$('#my_autocomplete_field').bind('railsAutocomplete.select', function(event, data){
  /* Do something here */
  alert(data.item.id);
});

Formtastic

If you are using Formtastic, you automatically get the autocompleted_input helper on semantic_form_for:

semantic_form_for @product do |f|
  f.input :brand_name, :as => :autocomplete, :url => autocomplete_brand_name_products_path
end

The only difference with the original helper is that you must specify the autocomplete url using the :url option.

SimpleForm

If you want to use it with simple_form, all you have to do is use the :as option on the input and set the autocomplete path with the :url option.

simple_form_for @product do |form|
  form.input :name
  form.input :brand_name, :url => autocomplete_brand_name_products_path, :as => :autocomplete

Cucumber

I have created a step to test your autocomplete with Cucumber and Capybara, all you have to do is add the following lines to your env.rb file:

require 'cucumber/autocomplete'

Then you'll have access to the following step:

I choose "([^"]*)" in the autocomplete list

An example on how to use it:

@javascript
Scenario: Autocomplete
  Given the following brands exists:
    | name  |
    | Alpha |
    | Beta  |
    | Gamma |
  And I go to the home page
  And I fill in "Brand name" with "al"
  And I choose "Alpha" in the autocomplete list
  Then the "Brand name" field should contain "Alpha"

I have only tested this using Capybara, no idea if it works with something else, to see it in action, check the example app.

Steak

I have created a helper to test your autocomplete with Steak and Capybara, all you have to do is add the following lines to your acceptance_helper.rb file:

require 'steak/autocomplete'

Then you'll have access to the following helper:

choose_autocomplete_result

An example on how to use it:

scenario "Autocomplete" do
  lambda do
    Brand.create! [
      {:name => "Alpha"},
      {:name => "Beta"},
      {:name => "Gamma"}
    ]
  end.should change(Brand, :count).by(3)

  visit home_page
  fill_in "Brand name", :with => "al"
  choose_autocomplete_result "Alpha"
  find_field("Brand name").value.should include("Alpha")
end

I have only tested this using Capybara, no idea if it works with something else.

Development

If you want to make changes to the gem, first install bundler 1.0.0:

gem install bundler

And then, install all your dependencies:

bundle install

Running the test suite

You need to have an instance of MongoDB running on your computer or all the mongo tests will fail miserably.

rake test

Integration tests

If you make changes or add features to the jQuery part, please make sure you write a cucumber test for it.

You can find an example Rails app on the integration folder.

You can run the integration tests with the cucumber command while on the integration folder:

cd integration
rake db:migrate
cucumber

Thanks to

Everyone on this list

About the Author

Crowd Interactive is an American web design and development company that happens to work in Colima, Mexico. We specialize in building and growing online retail stores. We don’t work with everyone – just companies we believe in. Call us today to see if there’s a fit. Find more info here!