Sinatra::FormHelpers - Lightweight form helpers for Sinatra

This plugin adds lightweight (3-5 lines each) form helpers to Sinatra that aid with common form and HTML tags.

link "google", "http://www.google.com"  # <a href="http://www.google.com">google</a>
label :person, :first_name              # <label for="person_first_name">First Name</label>
input :person, :first_name              # <input name="person[first_name]" id="person_first_name" type="text" />

There are also helpers for: form, textarea, submit, image, radio, checkbox, and select

Why Bother?

After all, you can just write Haml or write your own helpers or hand-code raw HTML or whatever. Well, here's some considerations:

Helpers maintain correct state across form submissions (eg, on errors, form stays filled in)
Generate automatic labels, valid CSS ID's, and nested[names] to make ORMs happy
No Rails ultra-magic(tm) here. Just fast, simple code.

Usage

With Bundler/Isolate:

gem 'sinatra-formhelpers-huii'

Then, include it in a Sinatra application:

require 'sinatra/form_helpers'

If you're subclassing Sinatra::Base, you also need to call helpers manually:

class MyApp < Sinatra::Base
  helpers Sinatra::FormHelpers
  # ...
end

Views

In your views, use these helpers to dynamically create form HTML elements. Here's an example in ERB:

<p>
  Fill out the below form to sign up.
  For more information, visit our <%= link 'FAQ', '/faq' %>
</p>

<%= form('/users', :post) %>

<%= input(:user, :first_name) %>
<%= input(:user, :last_name) %>

<%= input(:user, :email, :size => 40) %>

<%= password(:user, :password) %>
<%= password(:user, :confirm_password) %>

<%= radio(:user, :gender, ['M', 'F']) %>

<%= submit %>

Unlike the super-magic Rails form_for method, the form() helper just takes a URL and method. (Note that form() will accept :create, :update, and :delete and include the special _method hidden param for you.)

To reduce repetition, use fieldset() to prefix fields with a namespace:

<%= form('/users', :create) %>

<% fieldset(:user) do |f| %>
  <%= f.input(:first_name) %>
  <%= f.input(:last_name) %>

  <%= f.input(:email, :size => 40) %>

  <%= f.password(:password) %>
  <%= f.password(:confirm_password) %>

  <%= f.radio(:gender, ['M', 'F']) %>
<% end %>

</form> <-- You need to close it manually if you are not passing a block

<%= submit 'Create account' %>
<%= submit 'Cancel', :onclick => 'window.location=http://mydomain.com;return false' %>

<%= form(:user, :post, action: '/users') do |f| %> <-- This will create a fieldset automatically
  <%= f.input(:first_name) %>
  <%= f.input(:last_name) %>

  <%= f.input(:email, :size => 40) %>

  <%= f.password(:password) %>
  <%= f.password(:confirm_password) %>

  <%= f.radio(:gender, ['M', 'F']) %>
<% end %>

<%= submit 'Create account' %>
<%= submit 'Cancel', :onclick => 'window.location=http://mydomain.com;return false' %>

This will create fields named user[first_name], user[last_name], and so forth.

List of helpers so far

form
fieldset
link
image
label
input
password
email
textarea
submit
reset
button
checkbox
radio
select
hidden

Known Bugs

fieldset must be optional in form
<%= form(:user, :post, action: '/users') do |f| %> doesn't work in eRB, but works in Slim. Crap. :/

Fixed Bugs

Currently fieldset does not return a tag properly.
The state of select tags was not persisted across form submissions.

Running tests

Just run bundle exec rake or bundle exec rspec or rspec.

Authors

Initial efforts (c) 2009 Tom Wilson.
Additional efforts (c) 2011 Nate Wiger.
Further efforts (c) 2013 Cymen Vig.
Other efforts (c) 2014 Oldrich Vetesnik.

sinatra-formhelpers-huii

Development