defuse/defuse-global.js

A poor man's module namespacing solution for the browser

;(function() {
  var root;
  var defuse;

  if (typeof global != 'undefined') {
    // node
    root = global;
    defuse = this;
  }
  else {
    // browser
    root = this;
    root.defuse = defuse = {};
  }

  defuse.api = {};
  defuse.pending = {};
  defuse.registry = {};
  defuse.old = null;

  // Defines a module.
  defuse.api.def = function(name, loader) {
    defuse.pending[name] = loader;
    defuse.registry[name] = null;
    return this;
  };

  // Undefines a module.
  defuse.api.undef = function(name) {
    delete defuse.pending[name];
    delete defuse.registry[name];
    return this;
  };

  // Returns the exports of a defined module.
  defuse.api.use = function(name) {
    var mod = defuse.registry[name];

    if (typeof mod == 'undefined') {
      throw new Error("module '" + name + "' does not exist");
    }

    if (mod === null) {
      mod = {};
      defuse.pending[name](mod);
      defuse.registry[name] = mod;
      delete defuse.pending[name];
    }

    return mod;
  };

  // Assigns defuse's api methods to the given object
  defuse.assignTo = function(obj) {
    var api = defuse.api;
    for (var k in api) { obj[k] = api[k]; }
    return this;
  };

  // Assigns defuse's api methods to the global namespace (delegates to `assignTo`)
  defuse.pollute = function(obj) {
    var old = defuse.old = {};

    for (var k in defuse.api) {
      if (root.hasOwnProperty(k)) { old[k] = root[k]; }
    }

    defuse.assignTo(root);
    return this;
  };

  // Restore properties the global object had and remove properties that the
  // global object did not have before `pollute`.
  defuse.unpollute = function() {
    var old = defuse.old;

    if (old === null) {
      throw new Error("defuse has not been assigned to the global object");
    }

    for (var j in defuse.api) { delete root[j]; }
    for (var k in old) { root[k] = old[k]; }

    defuse.old = null;
    return this;
  };

  // Returns a shallow copy of the defuse api. Useful for mixing in
  defuse.exports = function() {
    var obj = {};
    defuse.assignTo(obj);
    return obj;
  };

  // Make the api methods directly accessible
  defuse.assignTo(defuse);
}).call(this);

if (typeof exports != 'undefined') {
    exports.pollute();
} else {
    defuse.pollute();
}