twbs--bootstrap/docs/getting-started/build-tools.md

layout	title	group
docs	Build tools	getting-started

Bootstrap uses Grunt for its CSS and JavaScript build system and Jekyll for the written documentation. Our Gruntfile includes convenient methods for working with the framework, including compiling code, running tests, and more.

Tooling setup

To use our Gruntfile and run our documentation locally, you'll need a copy of Bootstrap's source files, Node, and Grunt. Follow these steps and you should be ready to rock:

1. Download and install Node, which we use to manage our dependencies.
2. Install the Grunt command line tools, grunt-cli, with npm install -g grunt-cli.
3. Navigate to the root /bootstrap directory and run npm install to install our local dependencies listed in package.json.
4. Install Ruby, install Bundler with gem install bundler, and finally run bundle install. This will install all Ruby dependencies, such as Jekyll and plugins.

• Windows users: Read this unofficial guide to get Jekyll up and running without problems.

When completed, you'll be able to run the various Grunt commands provided from the command line.

Using Grunt

Our Gruntfile includes the following commands and tasks:

Task	Description
grunt	Run grunt to run tests locally and compile the CSS and JavaScript into /dist. Uses Sass, Autoprefixer, and UglifyJS.
grunt dist	grunt dist creates the /dist directory with compiled files. Uses Sass, Autoprefixer, and UglifyJS.
grunt test	Runs scss-lint, ESLint and QUnit tests headlessly in PhantomJS (used for CI).
grunt docs	Builds and tests CSS, JavaScript, and other assets which are used when running the documentation locally via jekyll serve.
grunt watch	This is a convenience method for watching just Sass files and automatically building them whenever you save.

Switching Sass compilers

Bootstrap will be compiled with libsass by default, but you can opt into traditional Ruby Sass by setting the TWBS_SASS environment variable. Two options are supported:

• libsass (default) to use libsass via grunt-sass.
• sass to use Ruby Sass via grunt-contrib-sass.

For example, run TWBS_SASS=sass grunt to test and build Bootstrap with Ruby Sass.

Autoprefixer

Bootstrap uses Autoprefixer (included in our Gruntfile and build process) to automatically add vendor prefixes to some CSS properties at build time. Doing so saves us time and code by allowing us to write key parts of our CSS a single time while eliminating the need for vendor mixins like those found in v3.

Local documentation

Running our documentation locally requires the use of Jekyll, a decently flexible static site generator that provides us: basic includes, Markdown-based files, templates, and more. Here's how to get it started:

1. Run through the tooling setup above to install Jekyll (the site builder) and other Ruby dependencies with bundle install.
2. From the root /bootstrap directory, run bundle exec jekyll serve in the command line.
3. Open http://localhost:9001 in your browser, and voilà.

Learn more about using Jekyll by reading its documentation.

Troubleshooting

Should you encounter problems with installing dependencies or running Grunt commands, uninstall all previous dependency versions (global and local). Then, rerun npm install.