Merge pull request #22 from Financial-Times/hashed-asset-helper

hack together a hashed asset helper

main.js

@@ -18,6 +18,7 @@ var topicUrl = require('./src/handlebars/topic-url');
 var dateformat = require('./src/handlebars/dateformat');
 var resize = require('./src/handlebars/resize');
 var encode = require('./src/handlebars/encode');
+var hashedAsset = require('./src/handlebars/hashed-asset');
 
 var flagsPromise = flags.init();
 
@@ -52,13 +53,15 @@ module.exports = function(options) {
 	app.locals.__name = name = normalizeName(name);
 	app.locals.__environment = process.env.NODE_ENV || '';
 	app.locals.__isProduction = app.locals.__environment.toUpperCase() === 'PRODUCTION';
+	app.locals.__rootDirectory = directory;
 	helpers.resize = resize;
 	helpers.dateformat = dateformat;
 	helpers.paragraphs = paragraphs;
 	helpers.removeImageTags = removeImageTags;
 	helpers.ifEquals = ifEquals;
 	helpers.ifAll = ifAll;
 	helpers.encode = encode;
+	helpers.hashedAsset = hashedAsset;
 	helpers.topicUrl = topicUrl;
 
 	app.use('/' + name, express.static(directory + '/public', {

src/handlebars/hashed-asset.js

@@ -0,0 +1,18 @@
+"use strict";
+module.exports = function(options) {
+	var assetHash;
+	var file = options.fn(this);
+	try {
+		assetHash = require(options.data.root.__rootDirectory + '/public/' + file + '-asset-hash.json')[file];
+	} catch(err) {
+		if (process.env.NODE_ENV === 'production') {
+			throw new Error("./public/" + file + "-asset-hash.json not found, required for proper working of the application in production");
+		} else {
+			console.warn("./public/" + file + "-asset-hash.json not found.  Falling back to un-fingerprinted files.");
+		}
+	}
+	if (assetHash) {
+		file = assetHash;
+	}
+	return '/' + options.data.root.__name+'/' + file;
+};