A RequireJS compatible plugin to provide shimming capabilities declaratively.

use.js

/* RequireJS Use Plugin v0.1.0
 * Copyright 2012, Tim Branyen (@tbranyen)
 * use.js may be freely distributed under the MIT license.
 */
define({
  version: "0.1.0",

  // Invoked by the AMD builder, passed the path to resolve, the require
  // function, done callback, and the configuration options.
  //
  // Configuration format
  // --------------------------------------------------------------------------
  //
  // The string property used in attach will resolve to window[stringProp]
  // Functions are evaluated in the scope of the window and passed all
  // arguments.
  //
  // require.config({
  //   use: {
  //     "libs/underscore": {
  //       attach: "_"
  //     },
  //  
  //     "libs/backbone": {
  //       deps: ["use!underscore", "jquery"],
  //       attach: function(_, $) {
  //         return this.Backbone.noConflict();
  //       }
  //     }
  //   }
  // });
  // 
  // Or within a UMD module, where calling require.config multiple times will
  // overwrite prior values.
  // require.config({
  //   "use:libs/underscore": {
  //     attach: "_"
  //   },
  //   "use:libs/backbone": {
  //     deps: ["use!underscore", "jquery"],
  //     attach: function(_, $) {
  //       return this.Backbone.noConflict();
  //     }
  //   }
  // });
  //
  load: function(name, req, load, config) {
    var module = config.use && config.use[name];

    // No module to load so return early.
    if (!module) {
      if (config['use:' + name]) {
        // Default config.use to be an abject, so that we can store any
        // additional configutations as and when they appear.
        config.use = config.use || {};

        // Set the module, and copy the config data into the main config.use
        // variable, so that other modules can benefit from its existance.
        module = config.use[name] = config['use:' + name];
      } else {
        return load();
      }
    }

    // Read the current module configuration for any dependencies that are
    // required to run this particular non-AMD module.
    req(module.deps || [], function() {
      // Require this module
      req([name], function() {
        // Attach property
        var attach = module.attach;

        // If doing a build don't care about loading
        if (config.isBuild) { 
          return load();
        }

        // Return the correct attached object
        if (typeof attach == "function") {
          return load(attach.apply(window, arguments));
        }

        // Use window for now (maybe this?)
        return load(window[attach]);
      });
    });
  }
});