cheat sheets.

link_to_remote(name, options = {}, html_options = {})

Returns a link to a remote action defined by options[:url] (using the url_for
format) that‘s called in the background using XMLHttpRequest. The result of
that request can then be inserted into a DOM object whose id can be specified
with options[:update]. Usually, the result would be a partial prepared by the
controller with render :partial.

Examples:

  link_to_remote "Delete this post", :update => "posts",
    :url => { :action => "destroy", :id => post.id }
  link_to_remote(image_tag("refresh"), :update => "emails",
    :url => { :action => "list_emails" })

You can also specify a hash for options[:update] to allow for easy redirection
of output to an other DOM element if a server-side error occurs:

Example:

  link_to_remote "Delete this post",
    :url => { :action => "destroy", :id => post.id },
    :update => { :success => "posts", :failure => "error" }