ツールバー、ライブプレビュー、および既存のテキストエリアの WYSIWYG

import MarkdownEditor from 'markdown-text-editor';
new MarkdownEditor('#markdown-editor');

import MarkdownEditor, { type MarkdownEditorOptions, type ToolbarEntry } from 'markdown-text-editor';

// Without the annotation this compiles, the editor renders with the default
// toolbar, and nothing tells you why.
const config: MarkdownEditorOptions = {
    placeholder: 'Write...',
    toolbr: ['bold', 'preview'],   // Error: did you mean to write 'toolbar'?
};

// Building a toolbar conditionally
const toolbar: ToolbarEntry[] = ['bold', 'italic'];
if (canUpload) toolbar.push({ image: { fileInput: { uploadUrl: '/api/upload' } } });
toolbar.push('preview');

interface EditorProps {
    value: string;
    options?: MarkdownEditorOptions;
}

<script type="module">
  import MarkdownEditor from 'https://cdn.jsdelivr.net/npm/markdown-text-editor/+esm';
  new MarkdownEditor('#markdown-editor');
</script>

<form action="/api/save" method="POST">
  <textarea id="markdown-editor" name="content"># Hello World</textarea>
  <button type="submit">Save Content</button>
</form>

<script src="https://cdn.jsdelivr.net/npm/markdown-text-editor"></script>
<script>
  new MarkdownEditor('#markdown-editor');
</script>

const editor = new MarkdownEditor('#markdown-editor', {
  placeholder: 'Write your markdown...',
  toolbar: ['heading', 'bold', 'italic', 'strikethrough', 'ul', 'ol', 'checklist', 'blockquote', 'link', 'preview'],
});

# forms.py
class PostForm(forms.ModelForm):
    class Meta:
        model = Post
        fields = ['content']
        widgets = {
            'content': forms.Textarea(attrs={'class': 'markdown-editor'}),
        }

new MarkdownEditor('.markdown-editor');
// request.POST['content'] contains the markdown on submit

<textarea name="content" class="markdown-editor">{{ old('content') }}</textarea>
<script>new MarkdownEditor('.markdown-editor');</script>

document.addEventListener('turbo:load', () => {
    document.querySelectorAll('.markdown-editor:not([data-mde-init])').forEach(el => {
        el.setAttribute('data-mde-init', 'true');
        new MarkdownEditor(el);
    });
});

<textarea name="content" class="markdown-editor"></textarea>
<script src="https://cdn.jsdelivr.net/npm/markdown-text-editor"></script>
<script>new MarkdownEditor('.markdown-editor');</script>

<form method="POST" action="save.php">
  <textarea name="content" class="markdown-editor"></textarea>
  <button type="submit">Save</button>
</form>
<script src="https://cdn.jsdelivr.net/npm/markdown-text-editor"></script>
<script>new MarkdownEditor('.markdown-editor');</script>

import { useEffect, useRef } from 'react';
import MarkdownEditor from 'markdown-text-editor';

function MarkdownField({ name, defaultValue = '', onChange }) {
    const ref = useRef(null);

    useEffect(() => {
        const editor = new MarkdownEditor(ref.current, { onChange });
        return () => editor.destroy();
    }, []);

    return <textarea ref={ref} name={name} defaultValue={defaultValue} />;
}

<script setup>
import { ref, onMounted, onBeforeUnmount } from 'vue';
import MarkdownEditor from 'markdown-text-editor';

const el = ref(null);
const props = defineProps({ modelValue: { type: String, default: '' } });
const emit = defineEmits(['update:modelValue']);
let editor = null;

onMounted(() => {
    el.value.value = props.modelValue;
    editor = new MarkdownEditor(el.value, {
        onChange: value => emit('update:modelValue', value)
    });
});

onBeforeUnmount(() => editor?.destroy());
</script>

<template><textarea ref="el"></textarea></template>

new MarkdownEditor('#markdown-editor', {
    toolbar: ['bold', 'italic', {
        custom: {
            title: 'Callout',
            icon: '<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20">…</svg>',
            action(editor) {
                editor.insertText('> [!NOTE]\n> Something worth noting');
            }
        }
    }, 'preview']
});

toolbar: [
    'bold', 'italic',
    { custom: { title: 'Callout',   icon: svg1, action: insertCallout } },
    'ul', 'ol',
    { custom: { title: 'Signature', icon: svg2, action: insertSignature } },
    'preview'
]

action(editor) {
    const textarea = editor.usertextarea;
    const selected = textarea.value.slice(textarea.selectionStart, textarea.selectionEnd);
    const wrapped = `==${selected || 'highlight'}==`;

    // (text, where the caret lands, characters to leave outside the selection)
    editor.insertText(wrapped, wrapped.length, 0);
}

{ custom: {
    title: 'Highlight',
    icon: '<svg>…</svg>',
    shortcut: 'Ctrl+Shift+H',
    action: (editor) => editor.insertText('====', 2, 2)
}}

class EmbedTool extends MarkdownEditor.Tool {
    constructor(editor) {
        super(editor, 'Embed video');        // tooltip, and .embed-video-btn
        this.shortcut = 'Ctrl+Shift+E';      // optional
        this.button = this.createButton('<svg>…</svg>');
    }

    applySyntax(event) {
        const dialog = MarkdownEditor.modal(event, 'fj:max-w-sm', `
            <input type="url" class="embed-url fj:me-input fj:w-full">
            <button type="button" class="embed-go fj:me-btn fj:me-btn-sm">Insert</button>
        `, 'Embed');

        dialog.querySelector('.embed-go').addEventListener('click', () => {
            const url = dialog.querySelector('.embed-url').value.trim();
            if (url) this.editor.insertText(`\n<iframe src="${url}"></iframe>\n`);
            dialog.close();
        });
    }

    destroy() {
        // Called by editor.destroy(). Release anything you registered here.
    }
}

new MarkdownEditor('#markdown-editor', { toolbar: ['bold', EmbedTool, 'preview'] });

// (event, size classes, body HTML, aria label)
const dialog = MarkdownEditor.modal(event, 'fj:max-w-sm', '…', 'Embed');

const body = dialog.querySelector('textarea');
const bar = editor.createToolbar(body, ['bold', 'italic', 'strikethrough']);
dialog.querySelector('.body-toolbar').appendChild(bar);

// Default — line, col, and chars visible
new MarkdownEditor('#editor');

// Disable the footer entirely
new MarkdownEditor('#editor', { footer: false });

// Hide only character count
new MarkdownEditor('#editor', { footer: { chars: false } });

// Hide line and column, keep character count
new MarkdownEditor('#editor', { footer: { line: false, col: false } });

// Show only line number
new MarkdownEditor('#editor', { footer: { col: false, chars: false } });

// Enable word count alongside the defaults
new MarkdownEditor('#editor', { footer: { words: true } });

// Show word count only
new MarkdownEditor('#editor', { footer: { line: false, col: false, chars: false, words: true } });

// Default initialization (Plain Mode)
new MarkdownEditor('#markdown-editor');

// Explicit Plain Mode
new MarkdownEditor('#markdown-editor', {
    mode: 'plain'
});

// Hybrid (Visual) Mode
new MarkdownEditor('#markdown-editor', {
    mode: 'hybrid'
});

<html data-theme="dark">
  ...
  <textarea id="markdown-editor"></textarea>
  <script>
    new MarkdownEditor('#markdown-editor'); // picks up dark automatically
  </script>

<textarea id="markdown-editor" data-theme="dark"></textarea>
<script>
  new MarkdownEditor('#markdown-editor');
</script>

new MarkdownEditor('#markdown-editor', {
    theme: 'dark'
});

/* Override individual variables */
.markdown-editor-wrapper {
    --color-primary: oklch(60% 0.2 30);   /* orange accent */
    --border-radius: 0.5rem;
}

/* Or define a full custom theme */
[data-theme="brand"] .markdown-editor-wrapper,
.markdown-editor-wrapper[data-theme="brand"] {
    --color-base:       oklch(15% 0.01 250);
    --color-on-base:    oklch(95% 0 0);
    --color-primary:    oklch(65% 0.22 145);   /* green */
    --color-on-primary: oklch(10% 0 0);
    --color-accent:     oklch(75% 0.18 60);
    --color-neutral:    oklch(80% 0 0);
    --border-radius:    0.75rem;
}

new MarkdownEditor('#markdown-editor', {
    labels: {
        'Bold': 'Gras',
        'Italic': 'Italique',
        'Heading': 'Titre',
        'Link': 'Lien',
        'Image link': 'Lien de l\'image',
        'URL': 'URL',
        'Alt text': 'Texte alternatif',
        'Apply': 'Appliquer',
        'Uploading...': 'Téléversement...',
    },
});

new MarkdownEditor('#markdown-editor', {
    toolbar: ['bold', 'italic', 'link',
        { variables: [
            { label: 'Customer Name', value: '{{customer.name}}' },
            { label: 'Invoice No',    value: '{{invoice.number}}' }
        ]},
        'preview'
    ]
});

{ variables: [
    { label: 'Customer Name', value: '{{customer.name}}', sample: 'Hannes' },
    { label: 'Invoice No',    value: '{{invoice.number}}' }
]}

// textarea : Hi {{customer.name}}, invoice {{invoice.number}}
// preview  : Hi Hannes, invoice {{invoice.number}}

{ variables: [
    { label: 'Today', value: '{{today}}', sample: '10 September 2026' },
    { label: 'Customer', items: [
        { label: 'Name',  value: '{{customer.name}}',  sample: 'Hannes' },
        { label: 'Email', value: '{{customer.email}}', sample: 'hannes@example.com' }
    ]},
    { label: 'Invoice', items: [
        { label: 'Number', value: '{{invoice.number}}' }
    ]}
]}

import MarkdownIt from 'markdown-it';
import taskLists from 'markdown-it-task-lists';
import MarkdownEditor from 'markdown-text-editor';

const md = new MarkdownIt({ linkify: true, breaks: true }).use(taskLists);

new MarkdownEditor('#markdown-editor', {
    renderer: markdown => md.render(markdown)
});

import DOMPurify from 'dompurify';

new MarkdownEditor('#markdown-editor', {
    renderer:  markdown => md.render(markdown),
    sanitizer: html => DOMPurify.sanitize(html, {
        ADD_TAGS: ['iframe'],
        ADD_ATTR: ['allow', 'allowfullscreen', 'frameborder']
    })
});

<script src="https://cdn.jsdelivr.net/npm/dompurify"></script>
<script src="https://cdn.jsdelivr.net/npm/markdown-text-editor"></script>

/* Variables set on the wrapper inherit down to every child */
.markdown-editor-wrapper {
    --border-radius: 12px;   /* rounds the editor and its toolbar buttons */
    --color-primary: oklch(60% 0.2 30);
}

/* Some variables are set by the component on itself, which beats an
   inherited value. Target the element directly for those. */
.markdown-editor-wrapper .markdown-btn {
    --btn--font-size: 0.875rem;
}

/* And use classes for anything no variable exposes */
.markdown-editor-wrapper .toolbar {
    border-bottom: 2px solid oklch(60% 0.2 30);
}

/* one editor only */
[data-editor="notes"] {
    --border-radius: 0;
}

/* every editor on the page */
.markdown-editor-wrapper {
    --mte-fullscreen-z-index: 20000;
}

/* one section only - the value inherits down */
#admin-panel {
    --mte-fullscreen-z-index: 20000;
}

/* a single editor, by its textarea id */
[data-editor="notes"] {
    --mte-fullscreen-z-index: 20000;
}

// Retrieve content via ID
const markdown = document.getElementById('markdown-editor').value;

// Set content via ID (The editor UI updates automatically)
document.getElementById('markdown-editor').value = "# New Heading Content";

const textarea = document.getElementById('markdown-editor');

// Retrieve content
const markdown = textarea.value;

// Set content (the editor UI reflects this immediately)
textarea.value = "## Updated via JS";

<!-- Recommended: set content server-side -->
<textarea id="markdown-editor"># Hello World</textarea>

const textarea = document.getElementById('markdown-editor');

// Read
const markdown = textarea.value;

// Update at runtime
textarea.value = '# New content';
editor.render();

const editor = new MarkdownEditor('#markdown-editor');

// Remove the editor and restore the plain textarea
editor.destroy();

const editor = new MarkdownEditor('#markdown-editor', {
    onChange(value) {
        console.log('Content changed:', value.length, 'characters');
    }
});

const DRAFT_KEY = 'my-page-draft';

// Restore saved draft before init (only if textarea starts empty)
const textarea = document.getElementById('markdown-editor');
const saved = localStorage.getItem(DRAFT_KEY);
if (saved && !textarea.value) textarea.value = saved;

// Save on every change
const editor = new MarkdownEditor('#markdown-editor', {
    onChange(value) {
        localStorage.setItem(DRAFT_KEY, value);
    }
});

// Clear draft after successful form submission
document.querySelector('form').addEventListener('submit', () => {
    localStorage.removeItem(DRAFT_KEY);
});

<form method="POST" action="/api/submit">
  <textarea id="markdown-editor" name="content" class="h-48" rows="5">
    # Initial Content
  </textarea>

  <button type="submit">Submit to Server</button>
</form>

<script>
  // Just initialize it. That's it.
  new MarkdownEditor('#markdown-editor');
</script>

const options = {
  placeholder: 'Start writing...',
  toolbar: [
    'link',
    {
      image: {
        fileInput: {
            accept: ['webp', 'avif'], // restrict the image upload format
            uploadUrl: '/api/upload', // Your upload endpoint
            params: {
                _token: 'your_csrf_token_here', // Essential for Laravel/Django
                folder: 'blog_posts'
            }
        },
        // Supports boolean: true/false OR object: { required: true }
        altInput: { required: true }
      }
    },
    'preview'
  ],
}
const editor = new MarkdownEditor('#markdown-editor', options);

{
  "success": true,
  "image_path": "https://cdn.yourdomain.com/uploads/image.webp"
}

{
  "success": true,
  "image_path": "https://cdn.yourdomain.com/uploads/image.webp",
  "image_alt": "Two people looking at a laptop"
}

// Alt text is REQUIRED by default
image: {
  fileInput: { uploadUrl: '/api/upload' }
}

image: {
  altInput: false // Users can now skip the alt text field
}

image: {
    altInput: {
        required: false // Disables alt text validation — users can skip the alt field
    }
}

const options = {
  toolbar: [
    'link',
    'image',
    'preview'
  ],
}
const editor = new MarkdownEditor('#markdown-editor', options);

Read the docs                        <- select "the docs", paste https://example.com
Read [the docs](https://example.com) <- what you get

const editor = new MarkdownEditor('#markdown-editor', {
    mode: 'hybrid',
    placeholder: 'Start writing...',
    footer: {
        line: true,
        col: true,
        chars: true,
        words: true,
    },
    onChange(value) {
        console.log('Content updated:', value.length, 'characters');
    },
    labels: {
        'Bold': 'Gras',
        'Italic': 'Italique',
        'Uploading...': 'Téléversement...',
    },
    toolbar: [
        'heading', 'bold', 'italic', 'strikethrough', 'blockquote',
        'ul', 'ol', 'checklist',
        'code', 'codeblock', 'hr', 'table',
        {
            image: {
                fileInput: {
                    accept: ['webp', 'avif', 'png'],
                    uploadUrl: '/api/upload'
                }
            }
        },
        'link', 'undo', 'redo', 'indent', 'outdent', 'preview'
    ],
});

// Read content natively
const markdown = document.getElementById('markdown-editor').value;

// destroy() when the view unmounts (SPAs)
// editor.destroy();