bem-core library

Documentation on bem-core in a much more informative way 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

The easiest way to run a project with bem-core is to use the project-stub.

You can use any other way you are familiar with to include the library into the project.

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

• querystring — helpers for work with querystring

• 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

• vow — Promises/A+ implementation

• 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/libs/bem-core/current/desktop/i-bem/jsdoc/

Changelog

You can check the changelog at the Changelog page.

Migration

If you used BEM before, check the migration instructions.

Development

Working copy

• Get the needed version code (e.g., v2):

  $ git clone -b v2 git://github.com/bem/bem-core.git
  $ cd bem-core
  

• Install the dependencies:

  $ npm install
  

  You need export PATH=./node_modules/.bin:$PATH or an alternative way to run locally-installed npm dependencies.

• Install all necessary libraries:

  $ npm run deps
  

• Build and run tests (specs):

  $ npm test
  

• Run development server:

  $ npm start
  

How to contribute

Please refer to How to contribute guide.

Modular testing

A default test bundle for functions__debounce:

$ magic make desktop.specs/functions__debounce

You can see the results of the tests in the terminal after the building process finishes.

You can also watch them in a browser loading desktop.specs/functions__debounce/spec-js+browser-js+bemhtml/spec-js+browser-js+bemhtml.html.

Run tests for other BEM entities in the same way. This will work for those which are equipped with .spec.js file.

Code coverage

To build code coverage report add ISTANBUL_COVERAGE=yes environment variable to the tests run command:

$ ISTANBUL_COVERAGE=yes magic make desktop.specs && istanbul report html

You can run modular testing with coverage as well by using more concrete build target as was described above.

$ ISTANBUL_COVERAGE=yes magic make desktop.specs/functions__debounce && istanbul report html

After tests finish, you can view coverage HTML report by opening coverage/index.html in your favorite browser.

The whole code coverage statistics can be found on the bem-core profile page on Coveralls.

Tests are built with a enb-bem-specs library. Check the details (available in Russian only).

Supported browsers

Our browser support policy is based on statistics we get from Yandex services.

Browsers with more than 2% users get full compliant support, more than 0.5% — partially compliant (which means that data is accessible but not necessary 100% functional). New features testing is not provided by us for  browsers with less than 0.5% users.

Desktop

Fully compliant

• Google Chrome 29+

• Firefox 24+

• Yandex 1.7+

• Opera 12.16

• MSIE 10.0

• MSIE 9.0

• MSIE 8.0

• Opera 12.15

Partially compliant

• Opera 17.0

• Opera 16.0

• Opera 12.14

• Opera 12.2

• Firefox 23

Touch

Fully compliant

• iOS 6+

• Android 2.3+

• Opera Mobile 12+

• Windows Phone 7+

Partially compliant

• iOS 5

• Android 2.2

License

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