Leaf

Visual WYSIWYG + Obsidian-style hybrid live preview + markdown editor for Phoenix LiveView.

Leaf Editor

Visual mode: contenteditable div with toolbar formatting (bold, italic, headings, lists, links, code blocks, tables, blockquotes, inline spoilers, etc.)
Hybrid mode (Obsidian-style live preview): formatting renders inline (bold, italic, strike, code, spoiler, headings, horizontal rule, lists) while the source markers stay editable — typing **word**, *word*, ~~word~~, ||word||, `word`, # heading, ---, - item, or 1. item auto-formats on the closing delimiter, and the markers fade in/out as the cursor enters and leaves each formatted run
Markdown mode: plain textarea with toolbar support
HTML mode: raw HTML editing for power users
Responsive toolbar: compact, stationary controls for narrow embeds and mobile comment editors; advanced tools progressively move into menus instead of requiring horizontal scrolling
Drag-and-drop reordering: drag any block element (headings, paragraphs, lists, images, blockquotes, code blocks) to rearrange content
Resizable: drag the bottom-right grip to change height; double-click the grip to auto-fit to content
Spoilers: Discord-style ||hidden|| markdown that renders as a click-to-reveal censored block in published content
Content syncs between modes via Earmark and client-side HTML→Markdown conversion
No npm dependencies — vendored JS bundle

Installation

Add leaf to your dependencies in mix.exs:

def deps do
  [
    {:leaf, "~> 0.2.0"}
  ]
end

JavaScript Setup

In your app.js, import the JS and register the hook:

import "../../../deps/leaf/priv/static/assets/leaf.js"

let liveSocket = new LiveSocket("/live", Socket, {
  hooks: {
    Leaf: window.LeafHooks.Leaf,
    // ... your other hooks
  }
})

CDN Alternative

If you prefer not to use the deps/ import path (e.g., non-standard project structure), you can load the JS from CDN instead:

// Load Leaf from CDN
const script = document.createElement("script");
script.src = "https://cdn.jsdelivr.net/gh/alexdont/leaf@v0.2.19/priv/static/assets/leaf.js";
script.onload = () => {
  // Leaf is now available at window.LeafHooks
};
document.head.appendChild(script);

Peer Requirements

Leaf's toolbar uses Tailwind CSS + daisyUI classes (btn, btn-xs, divider, textarea, etc.) and Heroicons CSS classes (hero-*). Make sure these are available in your project.

Usage

First, import the component in your view helpers (e.g., in my_app_web.ex):

import Leaf, only: [leaf_editor: 1]

Then use it in your templates:

<.leaf_editor
  id="my-editor"
  content={@content}
  mode={:visual}
  toolbar={[:image, :video]}
  placeholder="Write something..."
  readonly={false}
  height="480px"
  debounce={400}
/>

Alternative: direct LiveComponent syntax

<.live_component
  module={Leaf}
  id="my-editor"
  content={@content}
  mode={:visual}
  toolbar={[:image, :video]}
  placeholder="Write something..."
  readonly={false}
  height="480px"
  debounce={400}
/>

Assigns

Assign	Type	Default	Description
`id`	string	required	Unique editor ID
`content`	string	`""`	Markdown content
`mode`	`:hybrid` \| `:visual` \| `:markdown` \| `:html`	`:hybrid`	Initial editor mode
`preset`	`:advanced` \| `:simple`	`:advanced`	Toolbar preset; `:simple` is a compact subset for comments and lightweight editing
`toolbar`	list	`[]`	Extra toolbar buttons (`:image`, `:video`)
`placeholder`	string	`"Write something..."`	Placeholder text shown when the editor is empty
`readonly`	boolean	`false`	Read-only mode
`height`	string	`"480px"`	Editor height (the body resizes from this baseline)
`debounce`	integer	`400`	Debounce interval in ms for content-change events
`loading_preset`	atom	`:random`	Pre-mount loading label preset: `:random` picks from `:unpuzzling`, `:brewing`, `:polishing`, `:composing`, `:crafting`, `:tidying`. `:default` shows plain `"Loading…"`
`loading_text`	string	`nil`	Custom loading label; takes precedence over `loading_preset` when set
`upload_handler`	any	`nil`	Hint that the consumer supports uploads. When set, the main image button asks the parent for an upload via `:leaf_insert_request`; when `nil`, it opens the by-URL dialog directly
`class`	string	`nil`	Extra classes for the wrapper
`script_nonce`	string	`""`	CSP nonce for the inline `<style>` block

Messages to Parent

Handle these in your LiveView's handle_info/2:

def handle_info({:leaf_changed, %{editor_id: id, markdown: md, html: html}}, socket) do
  # Content was updated
  {:noreply, assign(socket, :content, md)}
end

def handle_info({:leaf_insert_request, %{editor_id: id, type: :image}}, socket) do
  # User clicked the image toolbar button — show your image picker
  {:noreply, socket}
end

def handle_info({:leaf_mode_changed, %{editor_id: id, mode: mode}}, socket) do
  # Mode switched between :visual and :markdown
  {:noreply, socket}
end

Commands from Parent

# Insert an image at the cursor position
send_update(Leaf, id: "my-editor", action: :insert_image, url: "https://...", alt: "description")

# Replace all content
send_update(Leaf, id: "my-editor", action: :set_content, content: "# New content")

# Switch mode programmatically
send_update(Leaf, id: "my-editor", action: :set_mode, mode: :markdown)

Gettext (optional)

To enable translations for toolbar tooltips:

# config/config.exs
config :leaf, :gettext_backend, MyApp.Gettext

Without this config, English strings are used as-is.

License

MIT — see LICENSE.