jsxstyle

jsxstyle is intended to be the best way to style React components. It has the goals of having a best-in-class developer experience without sacrificing performance, and has little regard for existing CSS orthodoxy :)

Philosophy

Many of the DOM nodes in your app exist solely for style purposes. Styling them can be cumbersome because of name fatigue (coming up with unique class names for nodes that don't need a name, like .outerWrapperWrapper), selector complexity, and constantly bouncing between your JS code and your CSS code in your editor.

jsxstyle believes that, for the nodes that exist for pure styling purposes, you should write styles inline with a friendly syntax, and furthermore, that just because you're writing your styles inline, doesn't mean that they actually get rendered into the browser that way (that is, there should be no performance penalty).

Hello world

npm install jsxstyle and then write code like this:

var Block = require('jsxstyle/Block');
var React = require('react');

var MyComponent = React.createClass({
  render: function() {
    return <Block color="red">Hello, world!</Block>;
  }
});

jsxstyle includes components corresponding to every potential value of the CSS display property. These include:

• Block
• Flex
• Inline
• InlineBlock
• InlineFlex
• Table
• TableCell
• TableRow

They all take props that correspond to every CSS style property (such as color, border, margin etc). You can also pass a few extra props, including:

• className: additional CSS classes you would like to apply
• component: the underlying HTML tag to render
• props: additional props to pass directly to the underlying HTML tag
• style: inline styles to apply

Pseudoclasses

jsxstyle makes it easy to use the common pseudoclasses :hover, :focus, and :active. You can prefix style props with the relevant pseudoclass to apply it:

var MyComponent = React.createClass({
  render: function() {
    return <Block color="red" hoverColor="yellow">Hello, world!</Block>;
  }
});

Helpers

jsxstyle has a few helpers extracted from Smyte's production application.

Flexbox helpers

jsxstyle includes Row and Col components, which correspond to <Flex direction="row"> and <Flex direction="column"> respectively.

Colors

You can create tasty CSS strings with jsxstyle.

Simple colors can be constructed with jsxstyle.rgb() and jsxstyle.rgba(). You can manipulate colors too:

var primaryBlue = jsxstyle.rgb(20, 20, 100);
var transparentBlue = jsxstyle.alpha(primaryBlue, 0.8);
var shadedBlue = jsxstyle.shade(primaryBlue, 0.8);

Want a linear gradient? Do:

jsxstyle.linearGradient(
  'to right',
  [[jsxstyle.rgb(255, 255, 255), '5%'], [jsxstyle.rgb(255, 0, 0), '25%']]
)

Style garbage collection

For big applications you'll want to call jsxstyle.install() to run the style garbage collector. This will periodically prune dead stylesheets from the browser to improve performance, especially in single-page apps.

Optimization: using the webpack loader

TODO

Optimization: extract a static stylesheet

TODO

Under the hood

At runtime, jsxstyle inserts stylesheets into the DOM that take the form of a single unique class name per node. If two or more nodes share the same styles, the stylesheet will be reused between the two nodes. Periodically, jsxstyle will reap stylesheets that were inserted into the DOM if they are no longer used.

At build time, you can enable optional loaders that will extract out static expressions (i.e. margin={5}) and expressions that only reference globally-known constants and precompile them into static style sheets. This has the advantage of reducing the number of props that React has to diff, and also, if you use JsxstylePlugin with webpack, will let you deliver a separate static .css file that can be cached and downloaded in parallel with the JS for maximum performance.

FAQ

Inline styles are bad.

jsxstyle is predicated on the idea that stylesheet rules are not a great way to reuse styles and that components are the correct abstraction. jsxstyle does not have many of the downsides of inline styles because the components are designed to be presentational only and do not render large strings of inline styles under the hood.

Is this used in production?

Yes, Smyte has used jsxstyle exclusively in production for almost two years.