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A JavaScript compacting middleware for express


A simple JavaScript compacting middleware for express

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npm install compact


Initialise compact:

var compact = require('compact').createCompact({
  srcPath: __dirname + '/public/src/',
  destPath: __dirname + '/public/compact/',
  webPath: '/js/compact/',
  debug: false
  • srcPath is the path to your frontend JavaScript. (If you initialised your project with Express' quick start, you probably want to set this to /public/javascripts).
  • destPath is the path that compact should use to store the compacted assets. If this directory does not exist, it will be created.
  • webPath is the public public facing route to your destPath (This will preceed the filename of the output <script> tags, so webPath: '/js/compact/' -> <script src="/js/compact/myscript.js">).
  • debug is optional. If set to true, the scripts will not be concatenated or minified.

Create namespaces:

Namespaces are used to create different compilations of scripts. Usually, you will want to create a global namespace that is used everywhere:


If you have some collection of scripts that will only be used on certain pages, it is a good idea to create a namespace for it. For example, if you have a banner and some ads that only appear on the homepage, and some UI that appears only on the profile page/section:


When creating a namespace, you can also pass in an extra srcPath. Calls to addJs() will look for the file in the given srcPath, and if not found it then tries the srcPath passed to createCompact().

compact.addNamespace('comments',  __dirname + 'libs/comments/public/src/' )

Using the middleware:

If you have created a global namespace, apply it to all routes like so:


This will expose the view helper compactJsHtml() in your templates, so you can output the necessary <script> tags.

Selectively apply namespaces to routes:

// Add some compacted JavaScript for just this route. Having the namespaces 
// in separate arrays will produce a javascript file per array. 
  compact.js(['home'], ['profile']),
  function (req, res) {
  /* Homepage logic here */
// Having different namespaces joined together 
// will combine and output as one javascript file. 
  compact.js(['comments', 'profile']),
  function (req, res) {
    /* Blog page logic here */

Note: compact must be applied to your route before the route logic. This is so that the view helper is available when you try to render your layout.

Bulk Config

You can defined all the namespaces and js files in a JSON schema using the configure function.

var compact = require('compact').createCompact(...);
    prepend: [
    append: [
    cmsSourcePath: '/public/vendor/cms/',
    cms: [

In this example you can see that you can either reference a JavaScript file or an existing namespace.


Any route that has compact.js() applied will have the helper function compactJsHtml() available. This will render the relevant script tags. In Jade, Use like so:


From the examples above, on / you'd get the following

<script src="/js/compact/global.js"></script>
<script src="/js/compact/home.js"></script>
<script src="/js/compact/profile.js"></script>

And on /blog you'd get this

<script src="/js/compact/global.js"></script>
<script src="/js/compact/comment-profile.js"></script>

You also have access to the compactJs() helper which will return an array of files instead of the rendered html.


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Licenced under the New BSD License