Typed styled components for ReScript, Melange and Native

styled-ppx is a ppx (opens in a new tab) and a library that brings styled components to ReScript, Melange and Native. It allows you to create React Components with type-safe style definitions that don't rely on a different language (DSL (opens in a new tab)) except CSS, but also can be used without React.

Built on top of emotion (opens in a new tab), it allows you to style apps safely, quickly, and performantly - just as you have always done it.

module Center = %styled.div(`
  height: 100vh;
  width: 100vw;
  display: flex;
  align-items: center;
  justify-content: center;
`)
 
<Center> {React.string("Hello from the future!")} </Center>
module Center = [%styled.div {|
  height: 100vh;
  width: 100vw;
  display: flex;
  align-items: center;
  justify-content: center;
|}];
 
<Center> {React.string("Hello from the future!")} </Center>;

Highlights

  • Type-safe CSS
  • Component-based styling
  • Implements utilities such as cx to generate classNames and css to generate Css.rules
  • 0 abstraction over standard CSS - it's neither a new language nor a DSL (opens in a new tab)
  • Supports the power of the underlying language: pattern-matching, composition, labelled arguments, etc
  • Integrates with [reason-react], [@resript-react] and [server-reason-react], accordingly
  • Adds labels for better DX

The main part of styled-ppx is a ppx. You can learn more about it in Tarides blog: Introduction to OCaml ppx ecosystem (opens in a new tab). Generally speaking, they are similar to babel plugins (opens in a new tab). They run before the compilation of your code, to transform your source-code. In this case, expands styled-ppx notations (e.g., %styled.div [%styled.div] or %cx [%cx]) into valid ReScript code.

ReScript