Breakup is a Sass component that allows you to create multiple CSS files from a single Sass partial by wrapping your code within breakpoint blocks. It allows you to abstract what your Sass partials folder looks like from what CSS files you create. Because of this you can easily create per-breakpoint CSS files (e.g. base, mobile, tablet and desktop) and fallback files where no styles are wrapped (e.g. for oldIE which does not support media queries).

The current trend towards OOCSS using Sass results in many small partials -- one per object. This is excellent for readability and reducing mental overhead until the complication of creating per-media query stylesheets, and oldIE stylesheets (where media queries are unsupported) appears. The simplest solution is to create even more partials named for each component's breakpoint (e.g. _component.scss & _component_wide.scss) but this results in a proliferation of partials which shall rapidly introduce noise to your partials folder.

Breakup allows you to write a single partial per object. By isolating each breakpoint's code inside a mixin block your output stylesheets can choose what blocks should be included within them and whether or not those blocks should even be wrapped inside a media query (for oldIE stylesheets you can serve the basic styles and the unwrapped wide styles so oldIE is given the wide view).

Breakup is compatible with both the origial ruby version of Sass and libsass. It is available as a rubygem and an npm package. If you don't wish to use either of these package managers you can also copy stylesheets/_breakup.scss into your project and @import it from there, as Breakup is written in pure SCSS and has no external dependencies.

Breakup is distributed as a Compass plugin.

• Run gem install breakup or add breakup to your Gemfile.
• Add require "breakup" to the top of your compass.rb
• Add @import 'breakup'; to your base stylesheets

Breakup is distributed as an npm package.

• Run npm install breakup-sass --save-dev
• Add @import 'node_modules/breakup-sass/stylesheets/breakup'; to your base stylesheets

The following examples can also be found in the examples/ folder

Blocks are chunks of SCSS to be output, they have arbitrary names. Breakpoints are blocks that have an attached media query that they shall be wrapped in.

First of all identify where your major breakpoints shall be and define them as a list of lists (where the sub-list contains two items: the breakpoint name and its media query it represents):

// _global_variables.scss
$breakup-breakpoints: (
  'thin' '(max-width: 35.999em)',
  'wide' '(min-width: 36em)',
  'full' '(min-width: 61em)'
);

Then in your component define the blocks and breakpoints that make up your component. In this example we want the 'basic' block to be output without any wrappers, but the 'wide' breakpoint shall be wrapped in an @media block.

// _component.scss
@include breakup-block('basic') {
  .component { background-color: red; }
}

@include breakup-breakpoint('thin') {
  .component { background-color: blue; }
}

@include breakup-breakpoint('wide') {
  .component { background-color: green; }
}

In your root scss file define what blocks should be rendered by defining the list $breakup-included-blocks:

// example_allblocks.scss
@import 'breakup';
$breakup-included-blocks: ('basic' 'thin' 'wide' 'full');

@import 'partials/global_variables';
@import 'partials/component';

This shall output:

.component {
  background-color: red;
}

@media (max-width: 35.999em) {
  .component {
    background-color: blue;
  }
}
@media (min-width: 36em) {
  .component {
    background-color: green;
  }
}

By changing $breakpoint-included-blocks we can change what boxes to include. To create a stylesheet that contains only our wide styles we can specify just the 'wide' block:

// example_wideonly.scss
@import 'breakup';
$breakup-included-blocks: ('wide');

@import 'partials/global_variables';
@import 'partials/component';

This shall output:

@media (min-width: 36em) {
  .component {
    background-color: green;
  }
}

OldIE doesn't understand media queries so we need to not wrap our breakpoints with an @media block, just output their contents as-is. This is controlled with $breakup-naked and $breakup-breakpoints-allow-naked. $breakup-naked: true tells breakup that it should not not wrap breakpoints up. $breakup-breakpoints-allow-naked is a list of breakpoints that should be output when $breakup-naked is true. By default this is empty and any breakpoints not specified shall be not be output, even if they are referenced in $breakup-included-blocks.

// example_oldie.scss
@import 'breakup.scss';

$breakup-included-blocks: ('basic' 'wide' 'full');
$breakup-naked: true;
$breakup-breakpoints-allow-naked: ('wide' 'full');

@import 'partials/global_variables';
@import 'partials/component';

This shall output:

.component {
  background-color: red;
}

.component {
  background-color: green;
}

Often we want smaller changes to occur at points between our major breakpoints. Instead of breaks in layout they are minor adjustments -- tweakpoints. This can be accomplished by wrapping a breakup-media within a breakup-block:

// _component.scss
@include breakup-block('wide') {
  @include breakup-media('(min-width: 40em)') {
    .component {
      background-color: green;
    }
  }
}

Breakup provides a convenience method for this so the following is a shorthand equivalent:

// _component.scss
@include breakup-tweakpoint('(min-width: 40em)', 'wide') {
  .component {
    background-color: green;
  }
}

More usage examples and tests coming soon.

The bulk of this project was conceived prior to learning about Jacket and Breakpoint. You could do something pretty similar by combining the two of them, but I didn't feel like I needed the extra overhead.