solid-codemirror

solid-codemirror provides a set of utilities to make CodeMirror6 integration easier for SolidJS.

This library was initially born to be the entry of the SolidJS hackathon, but has become the core editor of CodeImage.

Installation

# pnpm
> pnpm add solid-codemirror
# or yarn
> yarn add solid-codemirror
# or npm
> npm i solid-codemirror

Note This library depends on @codemirror/state and @codemirror/view v6.0.0. These libraries are flagged as ** peerDependencies**. It's recommended to manually install both of them to have more control and flexibility for implementation

CodeMirror packages error fix

Warning You may encounter this error using Vite

Error: Unrecognized extension value in extension set ([object Object]). 
This sometimes happens because multipleinstances of @codemirror/state are loaded, 
breaking instanceof checks.

If @codemirror/state and @codemirror/view are not working even if their version dont't mismatch, you can try to add the following to your vite.config.{js,ts} file:

export default defineConfig({
  // Your configuration
  optimizeDeps: {
    // Add both @codemirror/state and @codemirror/view to included deps to optimize
    include: ['@codemirror/state', '@codemirror/view'],
  }
})

Versions

solid-codemirror	@codemirror/state	@codemirror/view	solid-js
>=1.3.0	^6.2.0	^6.12.0	^1.7.0
>=1 < 1.3.0	^6.0.0	^6.0.0	^1.6.0

Basic Usage

First, we need to create a new CodeMirror instance through the createCodeMirror function. Next, the given ref object must be attached to a DOM Element in order to initialize the EditorView instance with his own EditorState.

import { createCodeMirror } from "solid-codemirror";
import { createSignal, onMount } from "solid-js";

export const App = () => {
  const { editorView, ref: editorRef } = createCodeMirror({
    /**
     * The initial value of the editor
     */
    value: "console.log('hello world!')",
    /**
     * Fired whenever the editor code value changes.
     */
    onValueChange: (value) => console.log("value changed", value),
    /**
     * Fired whenever a change occurs to the document, every time the view updates.
     */
    onModelViewUpdate: (modelView) => console.log("modelView updated", modelView),
    /**
     * Fired whenever a transaction has been dispatched to the view.
     * Used to add external behavior to the transaction [dispatch function](https://codemirror.net/6/docs/ref/#view.EditorView.dispatch) for this editor view, which is the way updates get routed to the view
     */
    onTransactionDispatched: (tr: Transaction, view: EditorView) => console.log("Transaction", tr)
  });

  return <div ref={editorRef} />;
};

The createCodeMirror function is the main function of solid-codemirror to start creating your editor. It exposes the following properties:

Property	Description
ref	The HTMLElement object which will be attached to the EditorView instance
editorView	The current EditorView instance of CodeMirror. Will be null as default, and it will be valued when the given ref is mounted in the DOM
createExtension	A function to create a new extension for CodeMirror using compartments. It's a shortand for the createCompartmentExtension helper which automatically attaches the right EditorView instance

Modularity

https://codemirror.net/docs/guide/
CodeMirror is set up as a collection of separate modules that, together, provide a full-featured text and code editor. On the bright side, this means that you can pick and choose which features you need, and even replace core functionality with a custom implementation if you need to. On the less bright side, this means that setting up an editor requires you to put together a bunch of pieces.

As the official documentation says, CodeMirror6 is modular.

solid-codemirror will not be a replacement for all the modules of CodeMirror6, but will try to provide only the primitives necessary to integrate them in SolidJS.

Each extension which you need to develop your editor must be installed individually and integrated individually.

Extensions

Control editor focus and observe focused state changes

import { createCodeMirror, createEditorFocus } from 'solid-codemirror';
import { createSignal } from 'solid-js';

const { editorView } = createCodeMirror();
const [readOnly, setReadOnly] = createSignal(true);
const {
  focused,
  setFocused
} = createEditorFocus(editorView, (focused) => console.log('focus changed', focused));

// Focus
setFocused(true);
// Blur
setFocused(false);

Update editor readonly state

After the CodeMirror editor is mounted, you can update its readonly state using the createReadonlyEditor function that accept the editor view and the readOnly accessor.

Note Updating the accessor, the editor readOnly state will be updated automatically;

import { createCodeMirror, createEditorReadonly } from 'solid-codemirror';
import { createSignal } from 'solid-js';

function App() {
  const { ref, editorView } = createCodeMirror();
  const [readOnly, setReadOnly] = createSignal(true);
  createEditorReadonly(editorView, readonly);

  return <div ref={ref} />
}

Control editor code using signals

After CodeMirror editor is mounted, you can control the code state using the createEditorControlledValue.

Note The value of the editor is already memoized

import { createCodeMirror, createEditorControlledValue } from 'solid-codemirror';
import { createSignal } from 'solid-js';

function App() {
  const [code, setCode] = createSignal("console.log('hello world!')");
  const { ref, editorView } = createCodeMirror({ onValueChange: setCode });
  createEditorControlledValue(editorView, code);

  // Update code after 2.5s
  setTimeout(() => {
    setCode("console.log('updated!')");
  }, 2500);

  return <div ref={ref} />
}

Handle custom extensions

After CodeMirror editor is mounted, you can handle custom extensions thanks to the createExtension function. It both accept an Extension or Accessor<Extension | undefined> then it will be automatically reconfigured when the extension changes. Otherwise, you can manually reconfigure them using the returned reconfigure function.

For more details, see the official documentation about compartments.

import { createCodeMirror } from 'solid-codemirror';
import { createSignal } from 'solid-js';
import { EditorView, lineNumbers } from '@codemirror/view';

function App() {
  const [code, setCode] = createSignal("console.log('hello world!')");
  const [showLineNumber, setShowLineNumber] = createSignal(true);
  const { ref, createExtension } = createCodeMirror({ onValueChange: setCode });

  const theme = EditorView.theme({
    '&': {
      background: 'red'
    }
  });

  // Add a static custom theme
  createExtension(theme);

  // Toggle extension
  createExtension(() => showLineNumber() ? lineNumbers() : []);

  // Remove line numbers after 2.5s
  setTimeout(() => {
    setShowLineNumber(false);
  }, 2500);

  return <div ref={ref} />
}

Lazy loading extensions

Sometimes you may need to better split your custom extensions in order to reduce the initial bundle size. This is the case where you need to use dynamic imports in order to resolve the module in lazy loading.

// ✅ 1. Remove the static import
// import { largeExtension } from './large-extension';
import { createLazyCompartmentExtension } from './createLazyCompartmentExtension';
import { Show } from 'solid-js';

function App() {
  const [code, setCode] = createSignal("console.log('hello world!')");
  const { ref, createExtension } = createCodeMirror({ onValueChange: setCode });

  // ✅ 2. Call the helper providing a Promise<Extension>
  // The extension will be configured only after the Promise resolves
  const largeExt = createLazyCompartmentExtension(
    () => import('./large-extension').then(res => res.largeExtension)
  );

  return (
    <div>
      <div ref={ref} />
      {/*✅ 3. You can read the pending state of the Promise*/}
      <Show when={largeExt.loading}>
        Loading...
      </Show>
    </div>
  )
}

Demo

// WIP

You can also view an advanced implementation of solid-codemirror through CodeImage implementation

Author

• Riccardo Perra

License

Licensed under the MIT License.