Code Playground - Add-on Mode

Add-on Mode in Code Playground allows you to develop and test complete add-ons with user interfaces directly in Adobe Express, without setting up a full development environment.

What is Add-on Mode?

Add-on Mode provides a complete development environment where you can:

Build user interfaces with HTML, CSS, and JavaScript.
Test add-on functionality in a real Adobe Express environment.
Prototype complete add-ons before building full projects.
Iterate quickly on UI and logic.

When to Use Add-on Mode

Use Add-on Mode when you want to develop, prototype, and test a complete add-on experience—especially when iterating quickly on UI, logic, and overall functionality within Adobe Express.

How to Use Add-on Mode

Step 1: Select Add-on Mode

Click the Add-on toggle (next to Script in the top left corner of the playground window).
You'll see four tabs for organizing your code: HTML, CSS, Iframe JS, and Document JS.

Code Playground Add-on Mode

Step 2: Write Your Code

Write code for your add-on in each of the supplied tabs. This includes HTML, CSS, and JavaScript code that will run in the iframe UI or in the Document Sandbox to interact directly with the Express document.

Step 3: Execute Your Add-on

Click Run Code to execute your add-on. Your add-on should open in an iframe on the right side of the Adobe Express window.

Step 4: Configure Manifest Properties (Optional)

If you need to set manifest properties for your add-on (e.g., if you want to use APIs that are currently marked experimental, set permissions, OAuth domains etc):

Click on the properties icon to open the Manifest JSON editing modal.
Configure the necessary properties.

Add-on Mode Manifest Settings

Understanding the Tabs

The Add-on mode features four tabs for organizing your code:

1. HTML Tab

This tab is for writing HTML code that defines the structure of your add-on's user interface. You can create elements like buttons, text fields, and layout containers here. Functionally, this tab mirrors the role of the index.html file you'd use in a typical add-on project.

Example:

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<div class="addon-container">
  <h2>My Add-on</h2>
  <button id="myButton">Click Me</button>
  <input type="text" id="myInput" placeholder="Enter text">
</div>

2. CSS Tab

Style your add-on's HTML elements in this tab. Create a visually appealing interface consistent with Adobe Express design patterns. This section corresponds to the styles.css file in a standard add-on project.

Example:

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.addon-container {
  padding: 20px;
  font-family: 'Adobe Clean', sans-serif;
}

#myButton {
  background-color: #0073e6;
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: 4px;
  cursor: pointer;
}

#myInput {
  width: 100%;
  padding: 8px;
  border: 1px solid #ccc;
  border-radius: 4px;
  margin-top: 10px;
}

3. Iframe JS Tab

This tab is for writing JavaScript code that runs in the iframe context of your add-on. Here, you can interact with:

The Add-on UI SDK (addOnUISdk).
The DOM elements in your HTML.
Event handlers for your UI components.

In case you are familiar with the add-on project structure, this tab corresponds to the code in the index.js file.

Example:

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// Wait for the add-on UI SDK to be ready
addOnUISdk.ready.then(() => {
  console.log('Add-on UI SDK is ready');

  // Get references to DOM elements
  const button = document.getElementById('myButton');
  const input = document.getElementById('myInput');

  // Add event listeners
  button.addEventListener('click', () => {
    const text = input.value;
    if (text) {
      // Send message to Document JS tab
      addOnUISdk.app.documentSandbox.dispatch({
        type: 'ADD_TEXT',
        payload: { text }
      });
    }
  });
});

4. Document JS Tab

This tab is where you write JavaScript code that interacts directly with the Adobe Express document. It runs in the Document Sandbox environment and gives you access to:

Document manipulation capabilities with the Document APIs.
Communication APIs to facilitate interaction between the iframe context and the Document Sandbox.

The Document JS tab corresponds to the code typically found in the code.js file of a complete add-on project.

Example:

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// Import necessary modules
import { editor, text } from 'express-document-sdk';

// Listen for messages from the iframe
addOnUISdk.app.documentSandbox.addEventListener('message', (event) => {
  if (event.data.type === 'ADD_TEXT') {
    addTextToDocument(event.data.payload.text);
  }
});

async function addTextToDocument(textContent) {
  try {
    // Create a new text node
    const textNode = await text.create({
      text: textContent,
      fontSize: 24,
      fontFamily: 'Arial'
    });

    // Add it to the document
    editor.context.insertNode(textNode);

    console.log('Text added to document');
  } catch (error) {
    console.error('Error adding text:', error);
  }
}

Key Differences from Script Mode

Feature	Script Mode	Add-on Mode
Global Await	Yes	No - must use async functions
Automatic Imports	Yes	No - must import manually
UI Building	No	Yes - full HTML/CSS/JS
API Access	Document APIs only	Document APIs + Add-on UI SDK