Add a special message when users copy text
Tags: tutorial, webdev, javascript
Published: 2023-12-27 02:59:37

Have you ever wanted to add a special message or attribution when users copy text from your website? For instance, when users select text and press `Ctrl + C` you might want to include the original website. That way, if users paste the content elsewhere, they'll see a message like this:

```html
The original text

Copied from https://www.yourwebsite.com
```

In this post, we'll learn how to achieve this specific behavior using JavaScript DOM. Typically, this behavior isn't applied to the entire page. Instead, it's used when users copy text from the main content section of the page. We'll assume that the markup has an element with the id of `content`.

```html
<div id="content">
    ...
</div>
```

Alright, let's dive in!

To select an element using JavaScript, we can use the `getElementById` method or any other method that fits your needs.

```js
const contentEle = document.getElementById('content');
```

## Handling the copy event

Now it's time to handle the `copy` event, which occurs when the user copies the text.

```js
contentEle.addEventListener('copy', (e) => {
    // We will add a custom message here ...
});
```

## Modifying the clipboard data

Within the event listener, we can modify the data that gets copied to the clipboard by using the `ClipboardEvent.clipboardData` property.

Unfortunately, the selected text cannot be obtained using the `clipboardData.getData()` function. It's only available when we handle the other events such as _paste_.

Fortunately, there's another way to [get the selected text](https://phuoc.ng/collection/html-dom/get-the-selected-text/): by using the selection API. By calling `window.getSelection().toString()`, we can retrieve the exact text that the user has selected.

The copy event handler could look like this:

```js
element.addEventListener('copy', (e) => {
    const clipboardData = e.clipboardData;
    const originalText = window.getSelection().toString();
    if (!originalText) {
        return;
    }

    // Modify the clipboard data
    e.preventDefault();
    clipboardData.setData('text/plain', originalText + '\n\n' + 'Copied from https://yourwebsite.com');
});
```

In this example, we're adding a new line with a custom message `Copied from https://yourwebsite.com` to the original text being copied. Then, we set the updated copy back to the clipboard using the `clipboardData.setData()` function.

But, here's the important part: make sure to prevent the default behavior of the `copy` event. This will keep the original text from being copied to the clipboard without the custom message.

```js
e.preventDefault();
```

Apart from using clipboard APIs, there is another way to save text to the clipboard. Check out this [post](https://phuoc.ng/collection/html-dom/copy-text-to-the-clipboard/) for more details.

Voila! With just a few lines of JavaScript DOM code, you can add a custom message to the text that users copy from your website.

Here's a live demonstration that you can play with! Check it out!

{% codepen https://codepen.io/phuocng/pen/rNRaoJe %}

## See also

-   [Copy highlighted code to the clipboard](https://phuoc.ng/collection/html-dom/copy-highlighted-code-to-the-clipboard/)
-   [Copy text to the clipboard](https://phuoc.ng/collection/html-dom/copy-text-to-the-clipboard/)
-   [Paste as plain text](https://phuoc.ng/collection/html-dom/paste-as-plain-text/)

---

It's highly recommended that you visit the [original post](https://phuoc.ng/collection/html-dom/add-a-special-message-when-users-copy-text/) to play with the interactive demos.

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