app.js

/*
 * Nunjucks + Express 
 * I couldn't find anything that helped me setup the enviornment
 * correctly for these in the latest vesion of Express 4 (at the time
 * of writing this).
 * 
 * This Gist for those that want to keep using Nunjucks with Express 4.
 * This also goes over working with a Nunjucks environment to use custom
 * filters, extensions, etc.
 *
 * You view files should have ".nunjucks" as the extension.
 *
 * - Caroline, 9/18/2014
 *
 */
 
var express     = require('express');
var nunjucks    = require('nunjucks');
var app         = express();
 
// view engine setup
app.set('views', path.join(__dirname, 'views'));

var env = nunjucks.configure(app.get('views'), {
    autoescape: true,
    express:    app 
});

//  Example filter setup - remote link assets
env.addFilter('asset', function(assetpath) {
    var asset_url = "/path/to/assets";      // can be a path, or an absolute web URL
    return asset_url + assetpath; 
});

app.set('view engine', 'nunjucks');

// Express App setup as per usual.