Formtastic form builder to generate Twitter Bootstrap-friendly markup.
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Formtastic Bootstrap

A Formtastic form builder that creates markup suitable for the Twitter Bootstrap framework. In theory, it should just work. Two great tastes in one!

You can follow FormBoot on twitter for update announcements and other relevant info.

Getting Started


Formtastic Bootstrap has only been tested with Ruby 1.9.2, Rails 3.1, Formtastic 2.0 and Twitter Bootstrap 1.3.


Install the gem with

gem install formtastic-bootstrap

Or add it to your Gemfile:

gem 'formtastic-bootstrap'

And install it with bundle install.


Add the following line to your Formtastic initialization file:

# config/initializers/formtastic.rb
Formtastic::Helpers::FormHelper.builder = FormtasticBootstrap::FormBuilder

Add the following line to the top of your application.css file:

# app/assets/stylesheets/application.css
*= require formtastic-bootstrap

Make sure you've already downloaded and installed Formtastic!

Formtastic vs. Formtastic Bootstrap


In general, Formtastic creates very verbose HTML whereas Bootstrap expects simpler HTML. Every attempt has been made to generate the HTML expected by Bootstrap while still generating the rich HTML provided by Formtastic. Here's a pretty typical (simplified) example of what Formtastic generates and what Formtastic Bootstrap generates.


<%= semantic_form_for @post do |f| %>
  <%= f.semantic_errors %>
  <%= f.inputs do %>
    <%= f.input :title, :hint => "This is the title!" %>
  <% end %>
  <%= f.buttons do %>
    <%= f.commit_button %>
  <% end %>
<% end %>


<form accept-charset="UTF-8" action="/posts" class="formtastic post" id="new_post" method="post">
  <fieldset class="inputs">
      <li class="string input optional stringish" id="post_title_input">
        <label class=" label" for="post_title">Title</label>
        <input id="post_title" maxlength="255" name="post[title]" type="text" value="" />
        <p class="inline-hints">This is the title!</p>
  <fieldset class="buttons">
      <li class="commit button">
        <input class="create" name="commit" type="submit" value="Create Post" />

Formtastic Bootstrap

<form accept-charset="UTF-8" action="/posts" class="formtastic post" id="new_post" method="post">
  <fieldset class="inputs">
    <div class="string clearfix optional stringish" id="post_title_input">
      <label class="" for="post_title">Title</label>
      <div class="input">
        <input id="post_title" maxlength="255" name="post[title]" type="text" value="" />
        <span class="help-inline">This is the title!</span>
  <div class="actions">
    <input class="btn create commit" name="commit" type="submit" value="Create Post" />

Major Difference in Behavior

  • Formtastic Bootstrap omits the label class on label tags since Twitter Bootstrap uses this tag in another context (and it makes bad things happen.)
  • Formtastic Bootstrap puts the input label in a different place because it makes Bootstrap behave correctly.
  • Formtastic Bootstrap renders :date, :datetime and :time as text fields since this is how Twitter Bootstrap presents these data types (Formtastic renders them as dropdowns.) Some Rails magic may have been lost here. Additionally:
    • :date et al are tagged with the stringish class.
    • Hidden fields are not generated.
  • Fieldsets are simply nested.
  • f.buttons :name is not supported. This generates a fieldset and legend tag which will cause the wrong thing to happen in Bootstrap.

Bootstrap is somewhat incomplete, and in a few cases an inference needed to be drawn to determine a course of action. If you disagree with any of these choices, feel free to let me know.

The gem also provides some "shim" CSS where Bootstrap is missing styles provided Formtastic.


A lot of the code (especially the test suite) was copied over from Formtastic and then beaten into submission. I'm sure you'll find some ugliness in there. In general, I mimicked the Formtastic code structure as much as possible.

In particular:

  • Bootstrap doesn't say anything about nested formfields.
  • Bootstrap doesn't explicitly lay out a :boolean control.
  • Bootstrap doesn't explicitly say everything that needs to be said about :datetime, :date, and :time.
  • I've inferred what :datetime should do since there's not example of a single :datetime.
  • In some places the markup is tortuous (e.g. :boolean.) Hopefully as Bootstrap evolves these can get simplified!
  • Bootstrap uses different HTML classes for sentence-based inline/block error messages.

What's Missing

Contributions are welcome!

  • Formtastic's :country has not yet been implemented.
  • Twitter Bootstrap's Date Range, Prepend Text, Prepend Checkbox and Appended Checkbox controls have not yet been implemented.



A big thank you to all contributors!

Submitting Issues

If you're filing a bug, thank you! Secondly, in the report please include:

  • The version of Formtastic you're using.
  • The version of Twitter Bootstrap you're using.
  • The code for your form.
  • Anything else you think will help!

Source Contributions

  • Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet
  • Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it
  • Fork the project
  • Start a feature/bugfix branch
  • Commit and push until you are happy with your contribution
  • Make sure to add tests for it and to run the test suite. If you don't have tests, I won't accept the pull. If you need help with this, please ask.
  • Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

To Do

  • Field Types
  • Basic Formtastic
    • :country
    • :time_zone
  • Fancy Bootstrap Fields
    • Date Range
    • Prepend Text
    • Prepend Checkbox
    • Appended Checkbox
  • :datetime, :date, :time
  • As rich functionally as their Rails counterparts.
  • Extract into a standalone gem.
  • Disabled inputs
  • Tests
  • Refactor
  • More -- See if I'm making sure the Bootstrap classes are present.
  • Documentation
  • Refactor :boolean to use common "choices" code (if possible.) (Not sure it is.)
  • Boostrap
    • Ask why they use 'inline-inputs' class instead of a fieldset tag.
    • Why 'help-inline' and 'help-block' when they could have done and


Copyright (c) 2011 Matthew Bellantoni. See LICENSE.txt for further details.