RequireJS 0.25.0 released, AMD advancing

RequireJS 0.25.0 is available for download.

It has been a few months since the last release, longer than normal. I have had some life changes (for good reasons) and I have busy at the day job. The interest in AMD loaders has picked up, and I have done some groundwork related to that interest. More information later in this post.

I wanted RequireJS 1.0 to be this release, but decided to name it 0.25.0 since I did some changes in the interest of better compatibility with other AMD loaders. Most applications should not notice the changes, but I want to have a release to shake out any problems on the edges.

Release Highlights

The awesome part: the optimizer is now just one JS file, r.js! It also doubles as a bootstrap script that supports the full capability of AMD modules and loader plugins in Node and in Rhino.

To use the optimizer, pass the "-o" option to r.js:

    node r.js -o app.build.js

To run your AMD-based project in Node (assuming server.js is your top-level AMD module):

    node r.js server.js

Running AMD modules in Node has more information. The optimizer docs have been updated to the new optimizer syntax, and the r.js script has its own project now, to allow releases that are decoupled from require.js.

Running r.js under Rhino is still supported, but you need to fetch a couple of JAR files first.

Other highlights:

• The loader plugin API changed to allow plugins to create cross-domain-accessible resources. The main use case: you use the text plugin to dynamically load text resources, but you want to deploy your scripts and text resources to a CDN. See the text plugin's implementation of writeFile() as an example.
  
• There is a global requirejs() function object that is the same as the global require() function object. This should allow RequireJS to work better in environments like Mozilla Chromeless, which already have a built-in require() function that does not have full AMD/loader plugin capabilities.
  
• It is now possible to specify the precise version of jQuery to allow in a RequireJS context. This is useful if you know of other scripts that load different versions of jQuery on a page.

Some changes in the name of compatibility with other AMD module loaders and Node:

• The "lib" directory configuration in package support was removed. It was always very awkward to support. Node no longer supports it, and that was the extra justification I needed to remove it.
• Relative module IDs are now relative to the related module ID, not the related module's resolved path.
• includeRequire in the optimizer config was removed, Use a paths config to include require.js instead. See the optimization docs for more details.

A small change to the context-specific require() passed to a loader plugin's load() call: require.isDefined() is now require.defined() and there is require. specified().

A New Home for AMD

Part of the RequireJS release delay was because the AMD API was moved off the CommonJS wiki and a set of compatibility tests were created.

While it was useful to hash out some of the basic goals and API on the CommonJS list, support for AMD on that list did not reach consensus. However, there has been continued and increasing interest in others making AMD-compatible loaders and tools. To avoid bothering people that would rather talk about other non-module things on the CommonJS list , a new AMD-focused discussion list and wiki has been set up and there is a set of compatibility tests.

AMD is advancing

More evidence that AMD is advancing:

• Alternate AMD loaders are available. Curl continues to advance, as well as the Dojo's 1.7 loader. Loadrunner has grown some basic support.
• There are at least two "AMD lite" projects, one in Ace, and one called DefineJS, that focus on basic AMD API support for when all the modules have been optimized into one file. The goal is to use a smaller bootstrap in optimized applications instead of a full standalone loader, like RequireJS.
• Node 0.5.0 supports the simplified CommonJS wrapper version of define(). While this support is very limited (no dependency array or loader plugins), it is a start to allowing some basic low-level module sharing between Node and browser apps better. See Kris Kowal's excellent Q library as an example of a module that works in both Node and in full AMD loaders.
• Look for better opt-in support for AMD in a couple of browser-focused libraries and toolkits later this year.
  

Path to RequireJS 1.0

For RequireJS, I want to get to a 1.0 when:

• 0.25.0 has been shown to work well in existing projects.
• Do some work around require.ready: possibly using a domReady plugin/module with optional loader hooks, to help improve cross-loader compatibility.
• Try to finalize more of the loader plugin API with other AMD implementers, to make sure more code can be shared across loaders. The loader plugin API is a separate API from basic AMD support, so I may push out a 1.0 before that API is completely final, and go to a 2.0 branch for any backwards incompatible changes to the loader API.