Can I call a Javascript function from a coffeescript file?

Question

I'm trying to call a javascript function from a Coffeescript file, for my $(document).ready() and it's never getting called.

The function I want to call comes from an external source that I have included in my html head element, just before the include of my coffeescript file, like this:

<script src="external.js"></script>
<%= javascript_include_tag params[:controller], 'data-turbolinks-track' => true %>

and in my coffeescript file (called someControllerName.coffee) I do this:

ready = ->
 ... call my method
$ -> ready

Is this the correct way? I can see in Chrome that my script is compile to javascript, and I can see it in the Network tab of the inspector.

I'm using Rails 4, and this is my application.js

//= require jquery
//= require jquery.turbolinks
//= require jquery_ujs
//= require bootstrap
//= require turbolinks
//= require_tree .

edit:

If I replace my method call by alert("..."); it works, and if I call my javascript method using javascript in $(document).ready() it works fine.

edit2:

Here's my real javascript function:

var ready = function () {
 $('pre code').each(function (i, e) {
 hljs.highlightBlock(e)
 });
};
$(document).ready(ready);

I solved the problem doing this:

highlight = ->
 $("pre code").each (i, e) ->
 hljs.highlightBlock(e)
$(document).on 'ready page:load', ->
 highlight()

• Sherwyn Goh: I reckon its probably your function within the coffeescript file? If alert works but not a method call it might be your method
• Pacane: I added my real javascript function, could you tell me how you would implement it in coffeescript?

Answer 1

This doesn't do what you think it does:

$ -> ready

In JavaScript that is:

$(function() {
 return ready;
});

Your problem is that just ready is simply a reference to the function, it is not a function call like it would be in Ruby. You'd have to say ready() to call the function, the function calling parentheses are only optional when you're calling a function with arguments: f x and f(x) are the same but f and f() are different.

I think you want to say:

$ -> ready()

or even:

$ ready # same as $(ready)

• Pacane: Thank you, now my function gets called, but it doesn't compile because of errors. I have included in my original post my real javascript function, if you could help me figuring out how to implement it in coffeescript.
• mu is too short: You got this figure out while I was away, right? You should be able to say just $(document).on 'ready page:load', ready too.