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Help develop Bootstrap with our documentation build scripts and tests.

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Tooling setup

Bootstrap uses npm scripts to build the documentation and compile source files. Our package.json houses these scripts for compiling code, running tests, and more. These aren’t intended for use outside our repository and documentation.

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

  1. Download and install Node.js, which we use to manage our dependencies.
  2. Either download Bootstrap’s sources or fork Bootstrap’s repository.
  3. Navigate to the root /bootstrap directory and run npm install to install our local dependencies listed in package.json.

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

Using npm scripts

Our package.json includes numerous tasks for developing the project. Run npm run to see all the npm scripts in your terminal. Primary tasks include:

Task Description
npm start Compiles CSS and JavaScript, builds the documentation, and starts a local server.
npm run dist Creates the dist/ directory with compiled files. Uses Sass, Autoprefixer, and terser.
npm test Runs tests locally after running npm run dist
npm run docs-serve Builds and runs the documentation locally.
Get started with Bootstrap via npm with our starter project! Head to the twbs/bootstrap-npm-starter template repository to see how to build and customize Bootstrap in your own npm project. Includes Sass compiler, Autoprefixer, Stylelint, PurgeCSS, and Bootstrap Icons.

Sass

Bootstrap uses Dart Sass for compiling our Sass source files into CSS files (included in our build process), and we recommend you do the same if you’re compiling Sass using your own asset pipeline. We previously used Node Sass for Bootstrap v4, but LibSass and packages built on top of it, including Node Sass, are now deprecated.

Dart Sass uses a rounding precision of 10 and for efficiency reasons does not allow adjustment of this value. We don’t lower this precision during further processing of our generated CSS, such as during minification, but if you chose to do so we recommend maintaining a precision of at least 6 to prevent issues with browser rounding.

Autoprefixer

Bootstrap uses Autoprefixer (included in our 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.

We maintain the list of browsers supported through Autoprefixer in a separate file within our GitHub repository. See .browserslistrc for details.

RTLCSS

Bootstrap uses RTLCSS to process compiled CSS and convert them to RTL – basically replacing horizontal direction aware properties (e.g. padding-left) with their opposite. It allows us only write our CSS a single time and make minor tweaks using RTLCSS control and value directives.

Local documentation

Running our documentation locally requires the use of Hugo, which gets installed via the hugo-bin npm package. Hugo is a blazingly fast and quite extensible 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 all dependencies.
  2. From the root /bootstrap directory, run npm run docs-serve in the command line.
  3. Open http://localhost:9001/ in your browser, and voilà.

Learn more about using Hugo by reading its documentation.

Troubleshooting

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

` const jsSnippetContent = jsSnippet ? '\/\/ NOTICE!!! Initially embedded in our docs this JavaScript\n\/\/ file contains elements that can help you create reproducible\n\/\/ use cases in StackBlitz for instance\.\n\/\/ In a real project please adapt this content to your needs\.\n\/\/ \u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\u002b\n\n\/\*!\n \* JavaScript for Bootstrap\u0027s docs \(https:\/\/getbootstrap\.com\/\)\n \* Copyright 2011\-2022 The Bootstrap Authors\n \* Copyright 2011\-2022 Twitter, Inc\.\n \* Licensed under the Creative Commons Attribution 3\.0 Unported License\.\n \* For details, see https:\/\/creativecommons\.org\/licenses\/by\/3\.0\/\.\n \*\/\n\n\/\* global bootstrap: false \*\/\n\n\(\(\) =\u003e \{\n \u0027use strict\u0027\n\n \/\/ \-\-\-\-\-\-\-\-\n \/\/ Tooltips\n \/\/ \-\-\-\-\-\-\-\-\n \/\/ Instantiate all tooltips in a docs or StackBlitz page\n document\.querySelectorAll\(\u0027\[data\-bs\-toggle=\u0022tooltip\u0022\]\u0027\)\n \.forEach\(tooltip =\u003e \{\n new bootstrap\.Tooltip\(tooltip\)\n \}\)\n\n \/\/ \-\-\-\-\-\-\-\-\n \/\/ Popovers\n \/\/ \-\-\-\-\-\-\-\-\n \/\/ Instantiate all popovers in a docs or StackBlitz page\n document\.querySelectorAll\(\u0027\[data\-bs\-toggle=\u0022popover\u0022\]\u0027\)\n \.forEach\(popover =\u003e \{\n new bootstrap\.Popover\(popover\)\n \}\)\n\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ Toasts\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ Used by \u0027Placement\u0027 example in docs or StackBlitz\n const toastPlacement = document\.getElementById\(\u0027toastPlacement\u0027\)\n if \(toastPlacement\) \{\n document\.getElementById\(\u0027selectToastPlacement\u0027\)\.addEventListener\(\u0027change\u0027, function \(\) \{\n if \(!toastPlacement\.dataset\.originalClass\) \{\n toastPlacement\.dataset\.originalClass = toastPlacement\.className\n \}\n\n toastPlacement\.className = `\$\{toastPlacement\.dataset\.originalClass\} \$\{this\.value\}`\n \}\)\n \}\n\n \/\/ Instantiate all toasts in a docs page only\n document\.querySelectorAll\(\u0027\.bd\-example \.toast\u0027\)\n \.forEach\(toastNode =\u003e \{\n const toast = new bootstrap\.Toast\(toastNode, \{\n autohide: false\n \}\)\n\n toast\.show\(\)\n \}\)\n\n \/\/ Instantiate all toasts in a docs page only\n const toastTrigger = document\.getElementById\(\u0027liveToastBtn\u0027\)\n const toastLiveExample = document\.getElementById\(\u0027liveToast\u0027\)\n if \(toastTrigger\) \{\n toastTrigger\.addEventListener\(\u0027click\u0027, \(\) =\u003e \{\n const toast = new bootstrap\.Toast\(toastLiveExample\)\n\n toast\.show\(\)\n \}\)\n \}\n\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ Alerts\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ Used in \u0027Show live toast\u0027 example in docs or StackBlitz\n const alertPlaceholder = document\.getElementById\(\u0027liveAlertPlaceholder\u0027\)\n const alertTrigger = document\.getElementById\(\u0027liveAlertBtn\u0027\)\n\n const appendAlert = \(message, type\) =\u003e \{\n const wrapper = document\.createElement\(\u0027div\u0027\)\n wrapper\.innerHTML = \[\n `\u003cdiv class=\u0022alert alert\-\$\{type\} alert\-dismissible\u0022 role=\u0022alert\u0022\u003e`,\n ` \u003cdiv\u003e\$\{message\}\u003c\/div\u003e`,\n \u0027 \u003cbutton type=\u0022button\u0022 class=\u0022btn\-close\u0022 data\-bs\-dismiss=\u0022alert\u0022 aria\-label=\u0022Close\u0022\u003e\u003c\/button\u003e\u0027,\n \u0027\u003c\/div\u003e\u0027\n \]\.join\(\u0027\u0027\)\n\n alertPlaceholder\.append\(wrapper\)\n \}\n\n if \(alertTrigger\) \{\n alertTrigger\.addEventListener\(\u0027click\u0027, \(\) =\u003e \{\n appendAlert\(\u0027Nice, you triggered this alert message!\u0027, \u0027success\u0027\)\n \}\)\n \}\n\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ Checks \u0026 Radios\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ Indeterminate checkbox example in docs and StackBlitz\n document\.querySelectorAll\(\u0027\.bd\-example\-indeterminate \[type=\u0022checkbox\u0022\]\u0027\)\n \.forEach\(checkbox =\u003e \{\n if \(checkbox\.id\.includes\(\u0027Indeterminate\u0027\)\) \{\n checkbox\.indeterminate = true\n \}\n \}\)\n\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ Links\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ Disable empty links in docs examples only\n document\.querySelectorAll\(\u0027\.bd\-content \[href=\u0022#\u0022\]\u0027\)\n \.forEach\(link =\u003e \{\n link\.addEventListener\(\u0027click\u0027, event =\u003e \{\n event\.preventDefault\(\)\n \}\)\n \}\)\n\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ Modal\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ Modal \u0027Varying modal content\u0027 example in docs and StackBlitz\n const exampleModal = document\.getElementById\(\u0027exampleModal\u0027\)\n if \(exampleModal\) \{\n exampleModal\.addEventListener\(\u0027show\.bs\.modal\u0027, event =\u003e \{\n \/\/ Button that triggered the modal\n const button = event\.relatedTarget\n \/\/ Extract info from data\-bs\-\* attributes\n const recipient = button\.getAttribute\(\u0027data\-bs\-whatever\u0027\)\n\n \/\/ Update the modal\u0027s content\.\n const modalTitle = exampleModal\.querySelector\(\u0027\.modal\-title\u0027\)\n const modalBodyInput = exampleModal\.querySelector\(\u0027\.modal\-body input\u0027\)\n\n modalTitle\.textContent = `New message to \$\{recipient\}`\n modalBodyInput\.value = recipient\n \}\)\n \}\n\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ Offcanvas\n \/\/ \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\n \/\/ \u0027Offcanvas components\u0027 example in docs only\n const myOffcanvas = document\.querySelectorAll\(\u0027\.bd\-example\-offcanvas \.offcanvas\u0027\)\n if \(myOffcanvas\) \{\n myOffcanvas\.forEach\(offcanvas =\u003e \{\n offcanvas\.addEventListener\(\u0027show\.bs\.offcanvas\u0027, event =\u003e \{\n event\.preventDefault\(\)\n \}, false\)\n \}\)\n \}\n\}\)\(\)\n' : null const project = { files: { 'index.html': markup, 'index.js': jsSnippetContent }, title: 'Bootstrap Example', description: `Official example from ${window.location.href}`, template: jsSnippet ? 'javascript' : 'html', tags: ['bootstrap'] } StackBlitzSDK.openProject(project, { openFile: 'index.html' }) }