AJAX on Rails 2.1

AJAX, short for Asynchronous JavaScript and XML, is a web technology that allows a web page to update without reloading the entire page. Rails is a web application framework written in the Ruby programming language. When combined, AJAX and Rails make for a powerful and efficient way to build modern web applications.

AJAX in Rails 2.1

Rails 2.1 introduced some great new features for working with AJAX. Here are some of the most notable additions:

respond_to

The respond_to method in Rails 2.1 allows you to specify different responses for different types of requests. For example, you can respond with HTML for a regular page request, but respond with JSON for an AJAX request.

def show
  @user = User.find(params[:id])

  respond_to do |format|
    format.html # show.html.erb
    format.json { render json: @user }
  end
end

remote_form_for

The remote_form_for method generates a form that submits via AJAX instead of reloading the page. This can greatly improve the user experience by reducing page reloads.

<%= remote_form_for @user do |f| %>
  <%= f.text_field :name %>
  <%= f.submit %>
<% end %>

:remote => true

You can also add :remote => true to any form tag to make it submit via AJAX.

<%= form_for @user, :remote => true do |f| %>
  <%= f.text_field :name %>
  <%= f.submit %>
<% end %>

link_to_remote

The link_to_remote method generates a link that triggers an AJAX request when clicked. This can be useful for adding interactivity to your web pages.

<%= link_to_remote "Load more", :url => { :action => "load_more" } %>

RJS templates

RJS is a template language that allows you to write Ruby code to generate JavaScript code. This can be an efficient way to generate JavaScript code for AJAX responses.

page["element_id"].replace_html :partial => "partial_name"

Conclusion

Rails 2.1 introduced some great new features for working with AJAX. Whether you're building a small web application or a large enterprise system, AJAX can help you deliver a more powerful and efficient user interface. By combining AJAX with Rails, you can build faster, more responsive web applications that will delight your users.