bem-core Library [](https://travis-ci.org/bem/bem-core)

This README 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
• ecma — some ES5 polyfils
• 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
• page — html/head/body scaffold

Technologies

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

Changelog

You can check the changelog at the changelog page.

Migration

If you used BEM before, check the migration instructions.

Development

Working copy

1. Get the needed version code (e.g., v1):

$ git clone -b v1 git://github.com/bem/bem-core.git
$ cd bem-core

2. Install the dependencies:

$ npm install

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

3. Install all the necessary libraries:

$ bower-npm-install

4. Build examples and tests:

$ bem make sets

5. Run development server:

$ bem server

How to contribute

1. Create an issue with a proper description.
2. Decide which version needs your changes.
3. Create a feature-branch with an issue number and a version (issues/<issue_number>@v<version_number>) based on a version branch. For example, for an issue #42 and a version #1: git checkout -b issues/42@v1 v1. If you need changes for several versions, each of them has to have a feature branch.
4. Commit changes and push. Rebase your branch on a corresponding version branch if it's needed.
5. Create a pull-request from your feature branch; or several pull-requests if you changed several versions.
6. Link your pull request with an issue number any way you like. A comment will work perfectly.
7. Wait for your pull request and the issue to be closed ;-)

Modular testing

A default test bundle for ecma_array:

$ bem make desktop.specs/ecma__array

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/ecma__array/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.

Tests are built with a bem-pr library. Check the details about testing infrastructure of the bem-pr.

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