Wellington adds spriting to the lightning fast libsass. No need to learn a new tool, this all happens right in your Sass!

Benchmarks

# Vanilla Sass from sass-spec
wt vanilla_css_huge.scss        0.10s user 0.01s system 98% cpu 0.120 total
compass vanilla_css_huge.scss   0.27s user 0.04s system 98% cpu 0.315 total
# 2.7x speedup

# 40,000 line of code Sass project
wt        14.935s
compass   73.800s
# 5x speedup!

Take a Sass file as follows:

$images: sprite-map("sprites/*.png");
div {
  width: image-width(sprite-file($images, "cat"));
  height: image-height(sprite-file($images, "cat"));
  background: sprite($images, "cat");
}

The following CSS file is generated

div {
  width: 140px;
  height: 79px;
  background: url("genimg/sprites-wehqi.png") 0px 0px;
}

You can try out Wellington on Codepen, fork the Wellington Playground!

Check out the Wellington collection

Wellington can be installed via brew

brew install wellington
wt -h

Run Wellington in docker

docker run -v $(pwd):/data -it drewwells/wellington wt proj.scss

Sprite-dimensions outputs the height and width properties of the specified image.

div {
  @include sprite-dimensions($spritemap, "file");
}

Output

div {
	width: 100px;
	height: 50px;
}

Don't see a function you want? Check out handlers and submit a pull request!

sprite-map generates a sprite from the matched images optinally with spacing between the images. No output is generated by this function, instead the return is used in other functions.

$spritemap: sprite-map("*.png");

Output

sprite generates a background url with background position to the position of the specified "image" in the spritesheet. Optionally, offsets can be used to slightly modify the background position.

div {
	background: sprite($spritemap, "image");
}

Output

div {
	background: url("spritegen.png") -0px -149px;
}

Sprite-file returns an encoded string only useful for passing to image-width or image-height.

div {
	background: sprite-file($spritemap, "image");
}

Output

div {
	background: {encodedstring};
}

image-height returns the height of the image specified by $path.

div {
	height: image-height(sprite-file($spritemap, "image"));
}
div {
	height: image-height("path/to/image.png");
}

Output

div {
	height: 50px;
}
div {
	height: 50px;
}

image-width returns the width of the image specified by $path.

.first {
	width: image-width(sprite-file($spritemap, "image"));
}
.second {
	width: image-width("path/to/image.png");
}

Output

.first {
	width: 50px;
}
.second {
	width: 50px;
}

inline-image base64 encodes binary images (png, jpg, gif are currently supported). SVG images are by default url escaped. Optionally SVG can be base64 encoded by specifying $encode: true. Base64 encoding incurs a (10-30%) file size penalty.

.png {
	background: inline-image("path/to/image.png");
}
.svg {
	background: inline-image("path/to/image.svg", $encode: false);
}

Output

.png {
	background: inline-image("data:image/png;base64,iVBOR...");
}
.svg {
	background: inline-image("data:image/svg+xml;utf8,%3C%3F...");
}

image-url returns a relative path to an image in the image directory from the built css directory.

div {
	background: image-url("path/to/image.png");
}

Output

div {
	background: url('../imgdirectory/path/to/image.png");
}

font-url returns a relative path to fonts in your font directory. You must set the font path to use this function. By default, font-url will return url('path/to/font'), set $raw: true to only return the path

div {
	$path: font-url("arial.eot", true);
	@font-face {
		src: font-url("arial.eot");
		src: url("#{$path}");
	}
}

Output

div {
	@font-face {
		src: url("../font/arial.eot");
		src: url("../font/arial.eot");
	}
}

Sass is a fantastic language. It adds a lot of power to standard CSS. If only our clients were happy with the functionality that Sass provided. For the life of Sass, there has been only one tool that attempted to extend Sass for everything that's needed to build a site. While Ruby is great for development, it does have some drawbacks. As our Sass powered website grew, Compass and Ruby Sass started to become a real drag on build times and development happiness. A typical build including transpiling Sass to CSS, RequireJS JavaScript, and minfication of CSS, JS, and images would spend half the time processing the Sass.

There had to be a better way. Libsass was starting to gain some traction, but it didn't do everything we needed. So I wrote Wellington to be a drop in replacement for the spriting functions familar to those used to Compass. This makes it super simple to swap out Compass with Wellington in your Sass projects.

Install Go and add $GOPATH/bin to your $PATH. Detailed instructions. Wellington requires Go 1.3.1+.

go get -u github.com/wellington/wellington
cd $GOPATH/src/github.com/wellington/wellington

make

# You should not have wt in your path
wt -h

It's a good idea to export PKG_CONFIG_PATH so that pkg-config can find libsass.pc. Otherwise, go ... commands will fail.

export PKG_CONFIG_PATH=$GOPATH/src/github.com/wellington/libsass/lib/pkgconfig

Set your fork as the origin.

cd $GOPATH/src/github.com/wellington/wellington
git remote rm origin
git remote add origin git@github.com:username/wellington.git

Testing

make test

Profiling

make profile

Build a Docker Container. The wt container is 33.6 MB in size, but builds in a much larger container 844.7 MB.

make build
make docker #launch a container

Please use pull requests for contributing code. CircleCI will automatically test and lint your contributions. Thanks for helping!

Wellington is licensed under MIT.