Calling javascript functions from controller

Question

Is it possible to call a javascript function from a controller in rails?

Answer 1

No, but you could output javascript that would be called immediately in your view e.g.

<script type="text/javascript">
   function IWillBeCalledImmediately()
   {
      alert('called');
   };
   IWillBeCalledImmediately();
</script>

However it would probably be better to use jquery and use the ready event.

<script type="text/javascript">
     $(function() { 
          alert('called');
      });
</script>

Answer 2

What I do is to make a Rails controller produce a javascript action. Is have it call a partial that has javascript included in it.

Unless you want that activated on page load, I would set it up via AJAX. So that I make an AJAX call to the controller which then calls a javascript file.

This can be seen via voting :

First the AJAX

//This instantiates a function you may use several times.

jQuery.fn.submitWithAjax = function() {
  this.live("click", function() {
    $.ajax({type: "GET", url: $(this).attr("href"), dataType: "script"});
    return false;
  });
};

// Here's an example of the class that will be 'clicked'
$(".vote").submitWithAjax();

Second the Controller

The class $(".vote") that was clicked had an attribute href that called to my controller.

def vote_up
  respond_to do |format|
    # The action 'vote' is called here.
    format.js { render :action => "vote", :layout => false }
  end
end

Now the controller loads an AJAX file

// this file is called vote.js.haml
==  $("#post_#{@post.id}").replaceWith("#{ escape_javascript(render :partial => 'main/post_view', :locals => {:post_view => @post}) }");

You have successfully called a javascript function from a controller.