Wednesday, August 28, 2013

Zazl AMD Optimizer and Node.js

When I first started writing the Zazl Optimizer I focused on providing a Java HTTP layer that could be used to support dynamic analysis and optimization of AMD based Web Applications. One of the  core analyzers within the Zazl AMD Optimizer is written in javascript, so with that in mind it made sense to also provide an HTTP layer written to run in Node.js.
Node.js has a number of static HTML libraries available. If one of those is combined with the Zazl AMD Optimizer you have an environment where you can write your AMD based application and serve up an optimized (concatenated and compressed) version of it to your browser based clients.

One of the most well known and used static HTML libraries is Connect. It's actually used within a large number of middleware Node.js based libraries such as Express. For the Zazl Optimizer's  purposes connect is used to serve up any static resource that is not handled by the optimizer. The packaging of the Zazl Optimizer for Node.js provides a Connect based server frontend. The section that starts up the http server looks like this (from the file found here):

    var connectOptimizer = zazloptimizer.createConnectOptimizer(appdir, compress);

    var app = connect()
        .use("/_javascript", connectOptimizer)


When creating the optimizer you give it the path to where the JavaScript resources reside and also whether to turn on compression. Also,  you can see above that the typical approach is taken to initialize the connect environment. The path is first checked for "_javascript" and directed to the optimizer to be handled if matched. Otherwise a Connect static handler for the specified application directory is search and also one to handle finding Zazl's AMD loader that the application code references. To take advantage of the AMD loader handler simply reference it as follows in the HTML file :

    <script type="text/javascript" src="loader/amd/zazl.js"></script>

That's more or less all there is to setting up usage. You can see more in two sample github repositories, one with Dojo samples and one with JQuery samples. Also both are hosted here and here.  

Note: The hosting site (Heroku) puts both apps to sleep after being idle for 1hour. Don't be surprised if the first load(s) takes some time. Subsequent loads will demonstrate the full potential. Alternatively you can download the source from the repositories and run them yourself.