Sunday, 21 November, 2021 UTC

Mitosis: Write components once, run everywhere

Mitosis: Write components once, run everywhere

Summary

mitosis
Write components once, run everywhere. Compiles to:
View Demo View Github
At a glance
Mitosis is inspired by many modern frameworks. You'll see components look like React components and use React-like hooks, but have simple mutable state like Vue, use a static form of JSX like Solid, compile away like Svelte, and uses a simple, prescriptive structure like Angular.
This is what a basic Mitosis component that manages some state looks like:
import { useState, Show, For } from '@builder.io/mitosis';

export default function MyComponent(props) {
  const state = useState({
    newItemName: 'New item',
    list: ['hello', 'world'],
    addItem() {
      state.list = [...state.list, state.newItemName];
    },
  });

  return (
    <div>
      <Show when={props.showInput}>
        <input
          value={state.newItemName}
          onChange={(event) => (state.newItemName = event.target.value)}
        />
      </Show>
      <div css={{ padding: '10px' }}>
        <button onClick={() => state.addItem()}>Add list item</button>
        <div>
          <For each={state.list}>{(item) => <div>{item}</div>}</For>
        </div>
      </div>
    </div>
  );
}
Learn more in the docs
CLI
Try Mitosis out locally with our CLI
npm install -g @builder.io/mitosis-cli

mitosis compile --to=vue my-file.lite.jsx
Why

Component libraries

Managing support for libraries that provide UI components across frameworks is a pain, especially when webcomponents are not an option (e.g. for server side rendering, best performance, etc). With Mitosis you can write once, and run everywhere while maintaining full compatibilty with the target framework.

Modern workflows for all platforms

Mitosis allows you to incrementally adopt modern and familiar workflows for many different platforms. For instance, when working with Shopify, you can server side render to liquid and hydrate with React.

JS framework fatigue

If you have ever had to migrate a huge codebase from one framework to another, it's an absolute nightmare. Writing components at a higher level of abstraction allows you to move from one to another with ease.

Design to code

With Mitosis, you can convert designs from Figma or Sketch and convert them to clean code for the framework of your choice. You can even use Builder.io to visually drag/drop to build UIs and edit the code side by side.
How does it work
Mitosis uses a static subset of JSX, inspired by Solid. This means we can parse it to a simple JSON structure, then easily build serializers that target various frameworks and implementations.
export function MyComponent() {
  const state = useState({
    name: 'Steve',
  });

  return (
    <div>
      <input
        value={state.name}
        onChange={(event) => (state.name = event.target.value)}
      />
    </div>
  );
}
becomes:
{
  "@type": "@builder.io/mitosis/component",
  "state": {
    "name": "Steve"
  },
  "nodes": [
    {
      "@type": "@builder.io/mitosis/node",
      "name": "div",
      "children": [
        {
          "@type": "@builder.io/mitosis/node",
          "bindings": {
            "value": "state.name",
            "onChange": "state.name = event.target.value"
          }
        }
      ]
    }
  ]
}
Which can be reserialized into many languges and frameworks. For example, to support angular, we just make a serializer that loops over the json and produces:
@Component({
  template: `
    <div>
      <input [value]="name" (change)="name = $event.target.value" />
    </div>
  `,
})
class MyComponent {
  name = 'Steve';
}
Adding framework support is surprisingly easy with the plugin system (docs coming soon).
Try it out
 
Use our Figma plugin to turn designs into code!
 
Try our interactive fiddle
 
Try our VS Code extension for in-IDE visual coding
 
Try our Shopify app for visual Shopify store building
 
Try our headless CMS for no-code APIs for all sites and apps
 
View our upcoming ecommerce integrations
No-code tooling
Mitosis's static JSON format also enables no-code tooling for visual code editing and importing. You can see this with Builder.io or Figma.
Formatting options
Mitosis supports settings for generating code to match your preferred formatting, libraries, etc. These output options will be customizable and extensible with plugins soon.
Who uses it
  • Builder.io
  • Snap
  • HTML <> Figma
  • Build. (coming soon)
Status
Framework Status
React Alpha
Vue Alpha
Liquid Alpha
Builder.io Alpha
Solid Alpha
Figma Alpha
Angular Alpha
Svelte Alpha
HTML/CSS/JS Alpha
Webcomponents Alpha
React Native Alpha
SwiftUI Experimental
Coming soon
  • Stable (v1) release
  • Plugin API docs for custom syntaxes and extensions
  • VS code plugin

... more @ reactjsexample.com

reactjsexample.com