bemto-components

bemto-components <🍱> [WIP]

Smart components for using parts of BEM methodology with React. Used best together with styled-components.

What does it do?

There are a lot of things bemto-components would do in the future, but for now here are a few main features:

1. bemto-components allow you to use BEM-style modifiers for your React components using the _modifier prop syntax. For ecample, if you'd do this (where the Foo is bemto-component): <Foo _bar />, each className of the Foo component would be duplicated with an addition of the _bar modifier. That allows you to use the BEM modifiers in your CSS (both any external, or using styled-components).

2. bemto-components gives you a way to easily create a component from a simple string that can contain an optional tag name (for now it defaults to div if omitted, but more on it coming, see the [3.]) and a bunch of classNames: bemto('span.myClass1.myClass2') would create a span component with the myClass1 myClass2, which would have all the other bemto features (like the applying of modifiers).

3. bemto-components gives you a way to easily create BEM “Elements” for your components.

4. coming soon bemto-components would allow you to think less about handling your components' tag names by embracing some prop-based polymorphism. More on it when it would be ready!

Disclaimer

Work in progress. Everything could change, don't treat as a stable thingy. I did not do any performance metrics and did not do any premature optimisations. Also: no tests for now. You're welcome to test, benchmark and overall think about this; create issues and PRs.

Install

npm install --save bemto-components

Example usage for modifiers

At definition:

import bemto from 'bemto-components';

const Block = bemto('div.myBlock');

Usage:

<Block _mod>
  Hello
</Block>

This would output

<div class='myBlock myBlock_mod'>Hello</div>

Modifiers with string values

Both boolean and string values are supported for modifiers:

<Block _mod1 _mod2='mod2value' />

With styled-components

Just pass a bemto-component inside styled-components:

import bemto from 'bemto-components'

const Block = styled(bemto('div'))`
  background: red;

  &_mod {
    background: lime;
  }
`)

Usage:

<Block _mod />

Just like this.

Example usage for elements

For bemto-components you can call .elem() method to create an element:

import bemto from 'bemto-components';

const Block = bemto('.myBlock');
Block.Element = Block.elem('myElement');

And then use it like this:

<Block>
  <Block.Element>Hello</Block.Element>
</Block>

Which would output

<div class='myBlock'><div class='myBlock__myElement'>Hello</div></div>

TagString for Elements

Like with creation of Blocks, you can use a tagString, passing it as a second param when creating an element:

import bemto from 'bemto-components';

const Block = bemto('.myBlock');
Block.Element = Block.elem('myElement', 'span.extraElemClass');

Again,

<Block>
  <Block.Element>Hello</Block.Element>
</Block>

Would output

<div class='myBlock'><span class='myBlock__myElement extraElemClass'>Hello</span></div>

With styled-components

As after wrapping with styled-component you would lose the elem method, there is an extra way to create elements:

import bemto from 'bemto-components'

const Block = styled(bemto())`
  background: red;

  &_mod {
    background: lime;
  }

  &__myElement {
    background: blue;
  }
`);

Block.Element = bemto.elem(Block, 'myElement', 'span.extraElemClass');

And there you'd even get the styled-components' names as block names.

Hint: if you have styled-components, you can emulate elements even without this lib:

It is already possible to kinda use Elements from BEM with react and/or styled components without adding anything extra:

const Block = styled.div`
  background: red;
`

Block.Element = styled.span`
  background: blue;
  
  ${Block}:hover & {
    background: lime;
  }
`

And in usage:

<Block>
  <Block.Element>Hewwo!</Block.Element>
</Block>

This way you can easily couple the element with its block. I have some plans on how we could use more familiar to BEM __elements, so keep in touch if interested!