Ember-cli-lazy-code

This addon is an inspiration from Google's startup latency blog.

This addon converts the app file's AMD modules into a string equivalent format. It primarily is used to lazily evaluate AMD modules by converting into an Object literal format that can be JSON stringified. This is very useful on low powered devices where we want to lazily evaluate javascript and only evaluate Javascript that is needed in the initial load.

Consider the following AMD modules:

define('a', ['exports', 'b', 'c'], function(_exports, _a, _b) {
  _exports.add = function add(n1, n2) {
    return _a.default(n1) + _b.default(n2);
  }
});
define('b', ['exports', 'c'], function(_exports, _c) {
  _exports.default = function addOne(n) {
    return _c.default(n) + 1;
  }
});
define('c', ['exports'], function(_exports) {
  _exports.default = function id(n) {
    return n;
  }
});

With an AMD module there 3 parts of the signature:

The module id string
The modules dependencies ids Array<string>
The anonymous function that executes the modules code. Called with the reified dependecies.

With this addon, we write an AST transform that captures the call of the define and re-writes it into an Object literal structure that can be JSON.stringifyed.

After the build, all app's AMD modules will be in this format by default:

{
  "a": {
    "imports": ["exports", "b", "c"],
    "arguments": ["_exports", "_b", "_c"],
    "body": "_exports.add = function add(n1, n2) { return _a.default(n1) + _b.default(n2); }"
  },
  "b": {
    "imports": ["exports", "c"],
    "arguments": ["_exports", "_c"],
    "body": "_exports.default = function addOne(n) { return _c.default(n) + 1; }"
  },
  "c": {
    "imports": ["exports"],
    "arguments": ["_exports"],
    "body": "_exports.default = function id(n) { return n;}"
  }
}

This addon only supports the strings mode currently. In future, we may add variations to this.

Since the format of the modules has been changed, we need to teach the loader.js to recognize this new format.

Note

When using this addon, please use ember-cli-string-module-loader addon instead of loader.js addon.

Installation

git clone this repository
npm install
bower install

Running

ember server
Visit your app at http://localhost:4200.

Running Tests

npm test (Runs ember try:testall to test your addon against multiple Ember versions)
ember test
ember test --server

Building

ember build