RequireJS: Local fallback for if CDN fails

Question

In my backbone app, I need to provide a fallback for each required file, in the case that the CDN that delivers them fails.

I have tried overwriting require.on

Answer 1

I have found a solution to the problem provided in RequireJS 2.x.x. There was a demand for this solution, so in turn, RequireJS added a paths object to their config. This provides fallback functionality for CDNs, should they fail.

It should also be noted that the order! plugin has been deprecated in Require 2.0, so I also needed to make use of the shim object to define dependencies. It's actually a pretty interesting idea.

Here is my new require.config:

require.config({
    urlArgs: "ts="+new Date().getTime(), // disable caching - remove in production
    paths: {
        jquery: [
            "http://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min",
            "libs/jquery"
        ],
        jqueryui: [
            "http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.23/jquery-ui.min",
            "libs/jqueryui"
        ],
        underscore: [
            "http://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.3.3/underscore-min",
            "libs/underscore"
        ],
        backbone: [
            "http://cdnjs.cloudflare.com/ajax/libs/backbone.js/0.9.2/backbone-min",
            "libs/backbone"
        ]
    },
    shim: {
        'jqueryui': ['jquery'],
        'underscore': ['jquery'],
        'backbone': ['underscore'],
        'core/core': ['underscore'],
        'core/errors': ['core/core'],
        'core/constants': ['core/core']
    }
});