Informant is a full-featured form builder for Ruby on Rails (works with Rails 3) which promotes a simple syntax that keeps your views clean. Everything about a field (label, description, error display, etc) is encapsulated in a single method call. Examples and general information are below; please read the API documentation for more complete/detailed information.

Install either as a plugin:

rails plugin install git://github.com/alexreisner/informant.git

or as a gem:

# add to config/environment.rb:
config.gem "informant"

# at command prompt:
bundle install

As a plugin:

script/plugin install git://github.com/alexreisner/informant.git -r rails_2

If you like you can set one of the Informant builders to be your application-wide default by adding something like this to your ApplicationHelper:

ActionView::Base.default_form_builder = Informant::Standard

However, this is not necessary. You can use choose your builder on a form-by-form basis with the :builder option to form_for. The available builders are:

Informant::Standard
Informant::Table
Informant::Simple

As an example, this view code:

<% form_for @car, :builder => Informant::Standard do |f| %>
  <% f.field_set "Details" do %>

    <%= f.text_field :name,
      :required => true,
      :description => "Something Italian, please." %>

    <%= f.select :manufacturer,
      %w[Ascari Ferrari Lamborghini Pagani] %>

    <%= f.integer_select :wheels,
      :label => "Number of wheels",
      :first => 2, :last => 4 %>

    <%= f.text_area :description %>

    <%= f.submit %>

  <% end %>
<% end %>

renders HTML like this (assuming the @car is a new record):

<form action="/cars" class="new_car" id="new_car" method="post">

  <!-- Rails' form authenticity token -->
  <div style="margin: 0pt; padding: 0pt;">
    <input name="authenticity_token" value="..." type="hidden" />
  </div>

  <fieldset>
    <legend>Details</legend>

    <div id="car_name_field" class="field">
      <label for="car_name">Name <span class="required">*</span></label><br />
      <input id="car_name" name="car[name]" size="30" value="" type="text" />
      <p class="field_description">Something Italian, please.</p>

</div>

    <div id="car_manufacturer_field" class="field">
      <label for="car_manufacturer">Manufacturer</label><br />
      <select id="car_manufacturer" name="car[manufacturer]">
        <option value="Ascari">Ascari</option>
        <option value="Ferrari">Ferrari</option>
        <option value="Lamborghini">Lamborghini</option>
        <option value="Pagani">Pagani</option>
      </select>
    </div>

    <div id="car_wheels_field" class="field">
      <label for="car_wheels">Number of wheels</label><br />
      <select id="car_wheels" name="car[wheels]">
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="4">4</option>
      </select>
    </div>

    <div id="car_description_field" class="field">
      <label for="car_description">Description</label><br />
      <textarea id="car_description" name="car[description]" cols="40" rows="20"></textarea>
    </div>

    <div class="button">  
      <input class="submit" id="car_submit" name="commit" value="Create" type="submit" />
    </div>

  </fieldset>
</form>

Note that the field label is inferred from the name if left blank, and the submit button (unless specified) says “Create” if the record is new, “Update” otherwise. There are other field options too. For a complete list please generate the API docs (cd vendor/plugins/informant; rake rdoc) or read them online.

Currently the following field methods are available:

• standard types

  • text_field

  • text_area

  • check_box

  • password_field

  • file_field

  • radio_button

  • hidden_field

  • select

  • time_zone_select

  • date_select

• extended types

  • integer_select

  • year_select

  • multipart_date_select

  • habtm_check_boxes

  • radio_buttons (note: plural)

Please see the inline documentation for arguments to each method.

• hierarchical AJAX select fields

• add documentation for all field types

• tests

  • custom options don’t appear in HTML tags

  • custom options work

Copyright © 2009 Alex Reisner, released under the MIT license