Gulp Overview

Gulp is a streaming build system that can help automate your workflow. We provide gulp tasks for the most important aspects of customizing our templates.


Make sure you have followed the gulp installation steps for your operating system.

Linux / Mac OS X


Additionaly, when running on Windows operating systems, do the following:

  1. remove the provided Gulpfile.js from the root directory of the project, if it already exists - it's a soft linux symlink and chances are the contents of this file is just a pointer to the real file which is located in lib/gulp/Gulpfile.js
  2. copy lib/gulp/Gulpfile.js in place of the file you removed at step 1.
  3. edit the following line in Gulpfile.js:

    requireDir('./tasks', {recurse: true});

    to look like this:

    requireDir('./lib/gulp/tasks', {recurse: true});
  4. When using Windows, make sure all the commands in this documentation are executed from either the Terminal builtin with SourceTree or a MSYS terminal. Don't use cmd.exe, it won't work! See installation on Windows.


Substitute $THEME_NAME where ever you see it thoughout the documentation instructions with a valid theme name. You can see the available themes by looking at the first level directories within src/html/themes.


Gulp provides a stream based build pipeline that connects files together across a number of processing steps, defining dependencies. The files content gets read and piped down a number of processing steps which results in the final assets that get used by the application.

Build paths

A build path is the destination directory where our final assets are placed after going through the build process. The build path is established with the --dist path/to/build CLI option.

For example:

gulp --theme $THEME_NAME build:d --dist build

Will build the application source into the build/$THEME_NAME/ destination directory. This path is not mandatory to exist previous to running the build:d task, it will be created if necessary.

The default build path without providing the --dist CLI option is dist/themes, so any build will create dist/themes/$THEME_NAME by default.

We can create persistent config overrides so that we don't have to specify a CLI option every time we want to have a custom build path for any specific build in the .build/dist.json file. To see the predefined build paths for this setup, please refer to this file.

For example, if we were to have the following .build/dist.json file:

    "my_theme": "",
    "my_second_theme": "custom"

When running:

gulp --theme my_theme build:d

Will create my_theme/ directory in the current working directory, at the project root.

And running:

gulp --theme my_second_theme build:d

Will similarily create custom/my_second_theme/ directory.

Note that we'll be referring to the build path throughout the documentation via $BUILD_PATH.

Concatenated files and bundles

In order to follow best practices, reduce the HTTP requests on any given page as much as possible and benefit from improved performance, we are using concatenation and bundles for serving our assets. Instead of having to load many files for all of the various libraries we use in our project, we only load a single file for everything with a single line of code in our HTML.

When using concatenated assets and bundles, our HTML pages might look like this:

<!DOCTYPE html>
<html lang="en">

    <!-- Vendor styling bundle -->
    <link rel="stylesheet" href="css/vendor/all.css" />

    <!-- Application styling bundle -->
    <link rel="stylesheet" href="css/app/app.css" />


    <!-- Vendor scripts bundle -->
    <script src="js/vendor/all.js"></script>

    <!-- Application scripts bundle -->
    <script src="js/app/app.js"></script>


Build with concatenated files and bundles

gulp --theme $THEME_NAME build:d

This is the fastest build task and has the following main characteristics:

  1. Does NOT generate minified assets.

    You can enable minification for both CSS and JavaScript:

    gulp --theme $THEME_NAME build:d --minify true

    And with source maps:

    gulp --theme $THEME_NAME build:d --minify true --debug true
  2. Compiles Less files into CSS:

    • src/less/themes/$THEME_NAME/app.less into $BUILD_PATH/$THEME_NAME/css/app/app.css (required)
    • src/less/themes/$THEME_NAME/main.less into $BUILD_PATH/$THEME_NAME/css/app/main.css
    • src/less/themes/$THEME_NAME/vendor/*.less into $BUILD_PATH/$THEME_NAME/css/vendor/*.css
  3. Bundles application JavaScript with Browserify:

    • src/js/themes/$THEME_NAME/app.js into $BUILD_PATH/$THEME_NAME/js/app/app.js (required)
    • src/js/themes/$THEME_NAME/main.js into $BUILD_PATH/$THEME_NAME/js/app/main.js
    • executes browserify tasks defined in .build/browserify.json
    • excluding tasks for which the build key starts with app/* (which are ignored)
  4. Compiles Swig template files into HTML:

    • src/html/themes/$THEME_NAME/**/*.html into $BUILD_PATH/$THEME_NAME/**/*.html
  5. Copies files, in the following order:

    1. src/images/common/* into $BUILD_PATH/$THEME_NAME/images/* - images stored here will end up in every theme
    2. src/images/themes/$THEME_NAME/* into $BUILD_PATH/$THEME_NAME/images/* - theme specific images
    3. executes copy tasks defined in .build/copy-*/copy.*.json (in path alphabetical order)
    4. executes copy tasks defined in .build/copy.json
  6. Concatenates files, in the following order:

    1. executes concat tasks defined in .build/concat-*/concat.*.json (in path alphabetical order)
    2. executes concat tasks defined in .build/concat.json
    3. excluding tasks for which the build key starts with js/app/* (which are ignored)

Note that the execution order of different tasks is important.

Separated libraries

We've covered concatenation and bundles, but what about separated libraries? There is also an option for those who don't want to use bundles or concatenated files and where our HTML could look like this:

<!DOCTYPE html>
<html lang="en">

    <!-- Separated vendor styling -->
    <link rel="stylesheet" href="css/vendor/bootstrap.css" />
    <link rel="stylesheet" href="css/vendor/font-awesome.css" />
    <link rel="stylesheet" href="css/vendor/morris.css" />
    <!-- etc. -->

    <!-- Separated application styling -->
    <link rel="stylesheet" href="css/app/main.css" />
    <link rel="stylesheet" href="css/app/sidebar.css" />
    <link rel="stylesheet" href="css/app/navbar.css" />
    <!-- etc. -->


    <!-- Separated vendor scripts -->
    <script src="js/vendor/core/jquery.js"></script>
    <script src="js/vendor/core/bootstrap.js"></script>
    <script src="js/vendor/core/jquery-ui.custom.js"></script>
    <!-- etc. -->

    <!-- Separated application scripts -->
    <script src="js/app/main.js"></script>
    <script src="js/app/essentials.js"></script>
    <script src="js/app/navbar.js"></script>
    <!-- etc. -->


Build with separated libraries

We definitely don't recommend this, but we won't stop you either. Here's how you can do it:

gulp --theme $THEME_NAME build:dm

Which is the same as:

gulp --theme $THEME_NAME build:d

But, with the following additional tasks:

  1. Compiles separated Less modules to CSS:

    • src/less/theme/$THEME_NAME/app/*.less into $BUILD_PATH/$THEME_NAME/css/app/*.css
  2. Bundles separated JavaScript modules with Browserify:

    • executes browserify tasks defined in .build/browserify.json
    • including tasks for which the build key starts with app/* (which are ignored with build:d)
  3. Concatenates separated JavaScript files which don't make use of Browserify and require:

    • executes concat tasks defined in .build/concat-app/concat.*.json
    • executes concat tasks defined in .build/concat.json
    • including tasks for which the build key starts with js/app/* (which are ignored with build:d)

Additionally, you can instruct Swig when it compiles into HTML, to automatically load the separated files instead of the bundles (so the final HTML output of your application will look similar to our example above):

gulp --theme $THEME_NAME build:dm --bundle false


gulp --theme $THEME_NAME

Starts a local web server and even opens your default browser on localhost on a dynamic free port. The web server is powered by BrowserSync, which means you can simultaneously track changes and synchronize the actions from your desktop browser with multiple devices while you're developing the application.

You can access the application from a mobile device via your private IP address and then if you refresh the page in your desktop browser, it will automatically refresh the application on your mobile device, but BrowserSync can do much more than a refresh (keeps in sync scoll position, click events, etc).

This also instructs gulp to watch your application files and rebuild when source files change and when it's done building, it will refresh your browser(s).


While we already introduced the most important tasks of the gulp workflow, build:d, build:dm and watch, there are several other tasks that are actually used by the build tasks themselves and that you can also use when you see fit.

Browserify tasks


gulp --theme $THEME_NAME browserify:main


gulp --theme $THEME_NAME browserify:modules


Runs all browserify tasks:

gulp --theme $THEME_NAME browserify

Code validation tasks


gulp --theme $THEME_NAME jshint

JavaScript compression tasks


gulp --theme $THEME_NAME uglify:all


Minifies the following JavaScript files:

gulp --theme $THEME_NAME uglify:theme


gulp --theme $THEME_NAME uglify:modules


gulp --theme $THEME_NAME uglify:main

CSS compression tasks


gulp --theme $THEME_NAME cssmin:vendor


Minifies the following CSS files:

gulp --theme $THEME_NAME cssmin:theme


gulp --theme $THEME_NAME cssmin:modules


gulp --theme $THEME_NAME cssmin:skins

Copy tasks


gulp --theme $THEME_NAME copy:images-common


gulp --theme $THEME_NAME copy:images-theme


Runs the following copy tasks:

gulp --theme $THEME_NAME copy:images


Runs the following copy tasks:

  1. copy:images
  2. executes copy tasks defined in .build/copy-*/copy.*.json (in path alphabetical order)
  3. executes copy tasks defined in .build/copy.json
gulp --theme $THEME_NAME copy:build

Concatenation tasks


  1. executes concat tasks defined in .build/concat-*/concat.*.json (in path alphabetical order)
  2. executes concat tasks defined in .build/concat.json
  3. excluding tasks for which the build key starts with js/app/* or css/app/* (which are ignored)
gulp --theme $THEME_NAME concat:dist


  1. executes concat tasks defined in .build/concat-*/concat.*.json (in path alphabetical order)
  2. executes concat tasks defined in .build/concat.json
  3. ONLY tasks for which the build key starts with js/app/* or css/app/*
gulp --theme $THEME_NAME concat:modules

Clean tasks


gulp --theme $THEME_NAME clean:html


gulp --theme $THEME_NAME clean:dist


gulp --theme $THEME_NAME clean:modules


gulp --theme $THEME_NAME clean:skins

HTML tasks


gulp --theme $THEME_NAME swig


gulp --theme $THEME_NAME prettify:theme

Less tasks


gulp --theme $THEME_NAME less:theme


gulp --theme $THEME_NAME less:modules


gulp --theme $THEME_NAME less:vendor


gulp --theme $THEME_NAME less:skins


Runs all the following less tasks:

gulp --theme $THEME_NAME less

See also