bem-core library

Documentation on bem-core is also available at bem.info. It is also available in Russian.

What is this?

bem-core is a base library for web interface development. It provides the minimal stack for coding client-side JavaScript and templating.

Use

Install as an npm dependency:

npm install bem-core@5

jQuery 4 is a peer dependency — install it alongside:

npm install jquery@^4.0.0

Inside

Levels

• common.blocks — suited for any devices and browsers
• desktop.blocks — should be used for desktop browsers
• touch.blocks — implement some touch-platforms specifics

Blocks

• i-bem — base block with helpers for JS and HTML
• strings — helpers for JS-strings
• objects — helpers for JS-objects
• functions — helpers for JS-functions
• events — JS-events
• uri — helpers for work with URIs and querystrings
• tick — global timer
• idle — IDLE event
• next-tick — polyfill for nextTick/setTimeout(0, ...)
• inherit — OOP helpers
• jquery — jQuery
• clearfix — CSS clearfix trick
• identify — identify JS-objects
• cookie — helpers for work with browser cookies
• dom — helpers for work with DOM
• loader — loader for JS files
• ua — browser features detection
• keyboard — keyboard helpers
• page — html/head/body scaffold

Technologies

• vanilla.js + browser.js
• bemhtml
• bemtree

API

The autogenerated JSDoc API can be found on bem.info. E.g. JSDoc for i-bem is here https://en.bem.info/platform/libs/bem-core/current/desktop/i-bem/#jsdoc

Changelog

See CHANGELOG.md.

Migration

If you are upgrading from v4, see MIGRATION.md.

Development

Working copy

1. Get the source code:

   git clone -b v5 git://github.com/bem/bem-core.git
   cd bem-core

2. Install the dependencies (requires Node.js 20+):

   npm install

3. Run linting:

   npm run lint

4. Run tests:

   npm test              # server-side tests (node:test)
   npm run test:browser  # browser tests (Playwright)
   npm run test:all      # both

5. Build:

   npm run build         # desktop + touch platforms

How to contribute

Please refer to How to contribute guide.

Supported browsers

• Google Chrome (latest)
• Firefox (latest)
• Safari (latest)
• Edge (latest)

License

Code and documentation copyright 2012 YANDEX LLC. Code released under the Mozilla Public License 2.0.