Catom
A 0 runtime css in js css tool
Stage: Pre Alpha (Caveats)
Catom allows you to write CSS in your javascript/typescript file and creates highly optimized CSS out of it.
Each rule creates a unique class definition out of it and it gives you 100% freedom about where to put your generated css bundle.
Your javascript code has 0 references to any styles and all that's left is are the compiled hashed clasnames as a string.
It's framework agnostic as it emits pure CSS and leaves out just the classnames
Example
somewhere in our App.js
import { css } from "catom";
const styledButton = css({
color: "#ff0000",
borderRadius: "5px",
padding: "4px",
});
const styledDiv = css({ color: "blue", borderRadius: "5px", padding: "4px" });
function App() {
return (
<div className={styledDiv}>
<button className={styledButton}>Hi</button>
</div>
);
}Css generated:
._6da32 {
color: #ff0000;
}
.quva1q {
border-radius: 5px;
}
._2rlxtj {
padding: 4px;
}
._14ksm7b {
color: blue;
}App.js:
const styledButton = "_6da32 quva1q _2rlxtj";
const styledDiv = "_14ksm7b quva1q _2rlxtj";
....As we had only 4 unique rules, catom generated only 4 classes.
Catom also supports media queries and pseudo properties passing them in an object
const mediaQuery = css({
media: { "only screen and (max-width:500px)": { color: "red" } },
});
const pseudoQuery = css({ pseudo: { ":hover": { color: "green" } } });Installation and Usage
Install using npm or yarn
npm i catom -D
In your babel config:
{
"plugins": [
"catom/babelPlugin"
`....
]
}As catom doesn't really interact with your build tool at all, it's your job to inject the generated style.
Here's an example of how you can use it with HTMLWebpackPlugin.
webpack.confg.js
const { emitCSS } = require("catom/css");
// ...
module.exports = {
plugins: [
new HtmlWebpackPlugin({
templateParameters: async function templateParametersGenerator(
compilation,
files,
tags,
options
) {
return {
compilation,
webpackConfig: compilation.options,
htmlWebpackPlugin: {
tags,
files,
options: Object.assign(options, {
emitCSS,
}),
},
};
},
}),
],
};and then inject it using a template parameter.
<head>
<style>
<%= htmlWebpackPlugin.options.emitCSS() %>
</style>
</head>it also allows you to use postCSS plugins by importing the transformCSS and/or autoPrefixCSS functions
0 Runtime
Catom ships with 0 js code in your bundle. In fact the first thing the babel transform does, is to remove all imports of the css function from your code.
Caveats
- It's just something I threw together because I wanted it for a project
- Not even close to production ready
- Since it works with AST, it does not allow you to use variable in the values (In work)
- No support for keyframes as of now