Padrino

Application Helpers

Unobtrusive JavaScript Helpers

Certain helpers have certain unobtrusive JavaScript options that are available to be used with any of the javascript adapters packaged with padrino. Once your app has been generated with a particular javascript adapter, you can utilize the baked in support with the link_to and form_for tags.

Remote Forms

To generate a 'remote' form in a view:

= form_for :user, url(:create, :format => :js), :remote => true do |f|
  .content=partial "/users/form"

which will generate the following unobtrusive markup:

<form data-remote="true" action="../../../items/create.js" method="post">
  <div class="content">
    <input type="text" id="post_title" name="post[title]">
    <input type="submit" value="Create">
  </div>
</form>
# /app/controllers/users.rb
post :create, :provides => :js do
  @user = User.new(params[:user])
  if @user.save
    "$('form.content').html('#{partial("/users/form")}');"
  else
    "alert('User is not valid');"
  end
end

A remote form, when submitted by the user, invokes an xhr request to the specified url (with the appropriate form parameters) and then evaluates the response as javascript.

To generate a 'remote' link in a view:

link_to "add item", url(:items, :new, :format => :js), :remote => true

which will generate the following unobtrusive markup:

<a href="../../../items/new.js" data-remote="true">add item</a>

A remote link, when clicked by the user, invokes an xhr request to the specified url and then evaluates the response as javascript.

To generate a 'confirmation' link in a view:

link_to "delete item", url(:items, :destroy, :format => :js), :confirm => "Are You Sure?"

which will generate the following unobtrusive markup:

<a data-confirm="Are You Sure?" href="/posts/destroy/7">[destroy]</a>

A link with confirmation, when clicked by the user, displays an alert box confirming the action before invoking the link.

To generate a 'method' link in a view:

link_to "logout", url(:session, :destroy, :format => :js), :method => :delete

which will generate the following unobtrusive markup:

<a data-method="delete" href="/posts/destroy/7" rel="nofollow">[destroy]</a>

A link with a custom method, when clicked by the user, visits the link using the http method specified rather than via the 'GET' method.

Enabling UJS Adapter

Note: In order for the unobstrusive javascript to work, you must be sure to include the chosen javascript framework and ujs adapter in your views (or layout). For instance, if I selected jquery for my project:

-# /apps/views/layouts/application.haml
= javascript_include_tag 'jquery', 'jquery-ujs', 'application'

This will ensure jquery and the jquery ujs adapter are properly loaded to work with the helpers listed above.

last updated: 2016-11-26

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