Ben d'état

Ben Scott

~/Cleaning and simplifying the Gulp pipeline

30 Jan 2015

DISCLAIMER: I’m learning in the open here. This is the first time I’ve used Gulp and Bower and I’m sure I’m missing a heap of really important stuff. Enjoy!

I wasn’t entirely happy with how the previous build script wrote out the minified JS and CSS files next to index.html, or how the vendor files had to be specified in the configuration, so I did some playing with the gulp-useref plugin and cleaned things up significantly.

I installed two new dependencies.


npm install --save-dev gulp-useref

Parse build blocks in HTML files to replace references to non-optimized scripts or stylesheets.


npm install --save-dev gulp-if

Conditionally run a task

I moved all the dependencies into $, deleted the dependencies I wouldn’t need any more and added useref:

var $ = {
	if: require('gulp-if'),
	notify: require('gulp-notify'),
	rev: require('gulp-rev'),
	revReplace: require('gulp-rev-replace'),
	useref: require('gulp-useref'),
	filter: require('gulp-filter'),
	uglify: require('gulp-uglify'),
	minifyCss: require('gulp-minify-css'),
	del: require('del'),
	path: require('path'),
	connect: require('connect'),
	serveStatic: require('serve-static'),
	log: require('gulp-load-plugins')()

Then I deleted the rev-and-inject task plus all of the CSS and JS tasks, and replaced the build task with this:

gulp.task('build', ['fonts', 'images'], function() {
	var cssFilter = $.filter('**/*.css');
	var jsFilter = $.filter('**/*.js');
	var assets = $.useref.assets();

	return gulp
		.src($.path.join(config.paths.client, '*.html'))
		.pipe($.if('*.js', $.uglify()))
		.pipe($.if('*.css', $.minifyCss()))

			onLast: true,
			message: 'Build complete'

$useref.assets() scans the .html files for JS and CSS references. The gulp-if plugin lets you do basic logic, this replaces the gulp-filter plugin to perform conditional minification. rev and revReplace do the same cache busting as before.

index.html now contains the relative references to the JS and CSS files. CSS is in the header:

    <!-- build:css content/site.min.css -->
    <link href="../../bower_components/bootstrap/dist/css/bootstrap.css" rel="stylesheet">
    <link href="../../bower_components/bootstrap/dist/css/bootstrap-theme.css" rel="stylesheet">
    <link href="content/css/site.css"/>
    <!-- endbuild -->

JS at the end of the body:

	<!-- build:js content/site.min.js -->
	<script type="text/javascript" src="../../bower_components/jquery/dist/jquery.js"></script>
	<script type="text/javascript" src="../../bower_components/bootstrap/dist/bootstrap.js"></script>
	<script type="text/javascript" src="content/script/site.js"></script>
	<!-- endbuild -->

The output path is specified in the build:css / build.js placeholder. Another benefit of this approach is that the development index.html is actually usable as is - those <script> and <link> will resolve to the un-mangled originals.

File watching

In the serve task (which sets up a static web server hosting the built site) I used to listen for changes in the source folder and trigger a build:

return + '/**', ['build']);

Now if a file changes, the files get rebuilt in the same process as the server. Because that server is just serving the entire source path any changes are available instantly.

Here is the gulpfile.js as at this post. Next I’ll get some AngularJS happening.

Further reading and resources

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