Javascript Dependency Manager

This plugin is a basic javascript dependency manager. It makes it simple to specify the dependencies for specific javascript files/libraries and implicitly include them.

Example Usage:
Add include JavascriptHelper in your ApplicationHelper.

# app/helpers/application_helper.rb
module ApplicationHelper
  include JavascriptHelper
end

Specify any dependencies in a method named js_dependencies (optional). Some default dependencies are defined already as a connivence for prototype and scriptaculous.

# app/helpers/application_helper.rb
module ApplicationHelper
  include JavascriptHelper

  def js_dependencies
    {
      # dialog_box.js requires effects.js and behaviour.js
      :dialog_box => [:effects, :behaviour] 
    }
  end
end

In your layout, add javascript_tags in the head of your HTML doc.

# app/views/layouts/default.html.erb
...
<head>
  <%= javascript_tags -%>
</head>
...

In your views, when you need to use the dialog_box.js library, just include it using the js helper method this plugin provides. The js method is an alias for the more verbose add_javascript_requirement method.

# app/views/users/new.html.erb
<% js :dialog_box %> # you can use a string or symbol for the name.

One caveat to be aware of is when requiring javascript from inside the layout, be careful to place the call to add_javascript_requirement before the javascript_tags line.

# app/views/layouts/default.html.erb
<% js :dialog_box %>
<%= javascript_tags -%>

That's it. It's a work in progress, feel free to contribute at http://github.com/arya/js_dependency_manager

Using Google AJAX Libraries

Google provides hosting for popular javascript libraries
http://code.google.com/apis/ajaxlibs/documentation/index.html

Using this plugin, you can opt to use libraries from their server rather than yours.

By default, only local (/public/javascripts/) javascripts are used but if you want to use Google's server, simply add this to an initializer:

JavascriptHelper::JavascriptHelperConfig.use_google_ajax_libs = true

You can put it in your environment files (development/production) to differentiate settings for development mode and production.

You can technically also put it in your application helper after include JavascriptHelper, but that's kind of ugly and not recommended.

If you set use_google_ajax_libs to true, when you do

js :prototype

it will yield

<script src="http://ajax.googleapis.com/ajax/libs/prototype/1.6.0.2/prototype.js" type="text/javascript"></script>

Here is a list of the libraries provided by Google:

jQuery
prototype
scriptaculous (builder, effects, dragdrop, controls, slider, sound)
mootools
dojo

If you wish to use the compressed version of the library, you can specify that like this:

JavascriptHelper::JavascriptHelperConfig.google_ajax_libs[:jQuery][:prefer_compressed] = true

Note: compressed versions are not provided for prototype or scriptaculous libraries.

By default, the latest versions of the libraries as of the updating of this plugin are used, but you can specify the version you want yourself like so:

JavascriptHelper::JavascriptHelperConfig.google_ajax_libs[:effects][:version] = "1.8.2"

js_dependency_manager

README.markdown

Javascript Dependency Manager

Using Google AJAX Libraries