Code Block

---
title: Code Block
docs:
  - route: https://pro.platejs.org/docs/components/code-block-node
    title: Plus
  - route: /docs/components/code-block-node
    title: Code Block Element
---

<ComponentPreview name="code-block-demo" />

<PackageInfo>

## Features

- Syntax highlighting for code blocks
- Support for multiple programming languages
- Customizable language selection
- Proper indentation handling

</PackageInfo>

## Kit Usage

<Steps>

### Installation

The fastest way to add code block functionality is with the `CodeBlockKit`, which includes pre-configured `CodeBlockPlugin`, `CodeLinePlugin`, and `CodeSyntaxPlugin` with syntax highlighting and [Plate UI](/docs/installation/plate-ui) components.

<ComponentSource name="code-block-kit" />

- [`CodeBlockElement`](/docs/components/code-block-node): Renders code block containers.
- [`CodeLineElement`](/docs/components/code-block-node): Renders individual code lines.
- [`CodeSyntaxLeaf`](/docs/components/code-block-node): Renders syntax highlighted text.

### Add Kit

Add the kit to your plugins:

```tsx
import { createPlateEditor } from 'platejs/react';
import { CodeBlockKit } from '@/components/editor/plugins/code-block-kit';

const editor = createPlateEditor({
  plugins: [
    // ...otherPlugins,
    ...CodeBlockKit,
  ],
});
```

</Steps>

## Manual Usage

<Steps>

### Installation

```bash
npm install @platejs/code-block lowlight
```

### Add Plugins

Include the code block plugins in your Plate plugins array when creating the editor.

```tsx
import { CodeBlockPlugin, CodeLinePlugin, CodeSyntaxPlugin } from '@platejs/code-block/react';
import { createPlateEditor } from 'platejs/react';

const editor = createPlateEditor({
  plugins: [
    // ...otherPlugins,
    CodeBlockPlugin,
    CodeLinePlugin,
    CodeSyntaxPlugin,
  ],
});
```

### Configure Plugins

Configure the plugins with syntax highlighting and custom components.

**Basic Setup with All Languages:**

```tsx
import { CodeBlockPlugin, CodeLinePlugin, CodeSyntaxPlugin } from '@platejs/code-block/react';
import { all, createLowlight } from 'lowlight';
import { createPlateEditor } from 'platejs/react';
import { CodeBlockElement, CodeLineElement, CodeSyntaxLeaf } from '@/components/ui/code-block-node';

// Create a lowlight instance with all languages
const lowlight = createLowlight(all);

const editor = createPlateEditor({
  plugins: [
    // ...otherPlugins,
    CodeBlockPlugin.configure({
      node: { component: CodeBlockElement },
      options: { lowlight },
      shortcuts: { toggle: { keys: 'mod+alt+8' } },
    }),
    CodeLinePlugin.withComponent(CodeLineElement),
    CodeSyntaxPlugin.withComponent(CodeSyntaxLeaf),
  ],
});
```

**Custom Language Setup (Optimized Bundle):**

For optimized bundle size, you can register only specific languages:

```tsx
import { createLowlight } from 'lowlight';
import css from 'highlight.js/lib/languages/css';
import js from 'highlight.js/lib/languages/javascript';
import ts from 'highlight.js/lib/languages/typescript';
import html from 'highlight.js/lib/languages/xml';

// Create a lowlight instance
const lowlight = createLowlight();

// Register only the languages you need
lowlight.register('html', html);
lowlight.register('css', css);
lowlight.register('js', js);
lowlight.register('ts', ts);

const editor = createPlateEditor({
  plugins: [
    // ...otherPlugins,
    CodeBlockPlugin.configure({
      node: { component: CodeBlockElement },
      options: {
        lowlight,
        defaultLanguage: 'js', // Set default language (optional)
      },
      shortcuts: { toggle: { keys: 'mod+alt+8' } },
    }),
    CodeLinePlugin.withComponent(CodeLineElement),
    CodeSyntaxPlugin.withComponent(CodeSyntaxLeaf),
  ],
});
```

- `node.component`: Assigns [`CodeBlockElement`](/docs/components/code-block-node) to render code block containers.
- `options.lowlight`: Lowlight instance for syntax highlighting.
- `options.defaultLanguage`: Default language when no language is specified.
- `shortcuts.toggle`: Defines a keyboard [shortcut](/docs/plugin-shortcuts) to toggle code blocks.
- `withComponent`: Assigns components for code lines and syntax highlighting.

### Turn Into Toolbar Button

You can add this item to the [Turn Into Toolbar Button](/docs/toolbar#turn-into-toolbar-button) to convert blocks into code blocks:

```tsx
{
  icon: <FileCodeIcon />,
  label: 'Code',
  value: KEYS.codeBlock,
}
```

### Insert Toolbar Button

You can add this item to the [Insert Toolbar Button](/docs/toolbar#insert-toolbar-button) to insert code block elements:

```tsx
{
  icon: <FileCodeIcon />,
  label: 'Code',
  value: KEYS.codeBlock,
}
```

</Steps>

## Plugins

### `CodeBlockPlugin`

<API name="CodeBlockPlugin">
<APIOptions>
  <APIItem name="defaultLanguage" type="string | null" optional>
    Default language to use when no language is specified. Set to null to disable syntax highlighting by default.
  </APIItem>
  <APIItem name="lowlight" type="ReturnType<typeof createLowlight> | null" optional>
    Lowlight instance to use for highlighting. If not provided, syntax highlighting will be disabled.
  </APIItem>
</APIOptions>
</API>

## API

### `isCodeBlockEmpty`

<API name="isCodeBlockEmpty">
<APIReturns type="boolean">
  Whether the selection is in an empty code block.
</APIReturns>
</API>

### `isSelectionAtCodeBlockStart`

<API name="isSelectionAtCodeBlockStart">
<APIReturns type="boolean">
  Whether the selection is at the start of the first code line in a code block.
</APIReturns>
</API>

### `indentCodeLine`

Indents the code line if the selection is expanded or there are no non-whitespace characters at left of the cursor. The indentation is 2 spaces by default.

<API name="indentCodeLine">
<APIOptions type="IndentCodeLineOptions">
  <APIItem name="codeLine" type="ElementEntry">
    The code line to be indented.
  </APIItem>
  <APIItem name="indentDepth" type="number">
    The size of indentation for the code line.
    - **Default:** `2`
  </APIItem>
</APIOptions>
</API>

### `insertCodeBlock`

Inserts a code block by setting the node to code line and wrapping it with a code block. If the cursor is not at the block start, it inserts a break before the code block.

<API name="insertCodeBlock">
<APIParameters>
  <APIItem name="insertNodesOptions" type="Omit<InsertNodesOptions, 'match'>" optional>
    Options for inserting nodes.
  </APIItem>
</APIParameters>
</API>

### `insertCodeLine`

Inserts a code line starting with the specified indentation depth.

<API name="insertCodeLine">
<APIParameters>
  <APIItem name="indentDepth" type="number" optional>
    The depth of indentation for the code line.
    - **Default:** `0`
  </APIItem>
</APIParameters>
</API>

### `outdentCodeLine`

Outdents a code line, removing two whitespace characters if present.

<API name="outdentCodeLine">
<APIOptions type="OutdentCodeLineOptions">
  <APIItem name="codeLine" type="ElementEntry">
    The code line to be outdented.
  </APIItem>
  <APIItem name="codeBlock" type="ElementEntry">
    The code block containing the code line to be outdented.
  </APIItem>
</APIOptions>
</API>

### `toggleCodeBlock`

Toggles the code block in the editor.

### `unwrapCodeBlock`

Unwraps the code block in the editor.