Embedded express Middleware

Sometimes you already have a server, but you want to use Harp as your asset pipeline, getting the benefits of Harp’s preprocessing.

This example combines the power of express with all the benefits of Harp, in one project. No external preprocessing, no complicated configuration, and no client-side parsers; just coding bliss. Best of all, setup is extremely easy.

  1. Add Harp as a dependency

    Include Harp as a dependency in the package.json file of your Express app.

     "name": "myapp",
     "version": "0.1.0",
     "dependencies": {
       "express": "3.x",
       "harp": "*"
  2. Use harp.mount

    Next, you’ll use harp.mount just like you would the static middleware.

    var express = require("express");
    var harp = require("harp");
    var app = express();
    app.use(express.static(__dirname + "/public"));
    app.use(harp.mount(__dirname + "/public"));
    // routes as normal
  3. Add your Harp app

    All done! Now you put your Harp app’s assets in the public directory. Here’s an example of what your public directory might look like:


You can pass data to your template the same way you do with a normal Harp app. For example, using _data.json:

  "index": {
    "title": "Hello World"

For global variables, use the _harp.json file, like this:

  "globals": {
    "foo": "bar"

Then you can use the title and foo variables in your index.ejs template like this:

<h1><%= title %></h1>
<p><%= foo %></p>

And that should output this:

<h1>Hello World</h1>