# Subscribe / unsubscribe to shopping cart events for InLine Checkout

## Overview

Subscribe and unsubscribe to Inline checkout events.

## Use case

1. Add an HTML link or button in your page like the one below.
2. Create a JavaScript click handler to execute the Inline Client desired methods.
3. Use the `TwoCoInlineCart.products.add({code, quantity, options})` method to prepare your catalog product.
4. In order to subscribe to an event use:<br>

   ```javascript
   TwoCoInlineCart.events.subscribe('cart:opened', function () {
       alert('Cart was opened.');
   });
   ```
5. In order to unsubscribe from an event use the Handler GUID that you can obtain when subscribing to the event.<br>

   ```javascript
   let cartClosedhandlerGuid = TwoCoInlineCart.events.subscribe('cart:closed', function () {
       alert('Cart was closed.');
   });
   TwoCoInlineCart.events.unsubscribe('cart:closed', cartClosedhandlerGuid);
   ```
6. Use the `TwoCoInlineCart.cart.checkout()` method to show the cart on your page.

## Sample request

### HTML

```html
<a href="#" class="btn btn-success" id="buy-button">Buy now!</a>
```

### JavaScript

```javascript
window.addEventListener('load', function() {
    TwoCoInlineCart.events.subscribe('cart:opened', function () {
      alert('Cart was opened.');
    });
    
    TwoCoInlineCart.events.subscribe('payment:finalized', function () {
      alert('Payment was finalized.');
    });
    
    TwoCoInlineCart.events.subscribe('fulfillment:finalized', function () {
      alert('Fulfillment was finalized.');
    });
    
    var cartClosedhandlerGuid = TwoCoInlineCart.events.subscribe('cart:closed', function () {
      alert('Cart was closed.');
    });
    TwoCoInlineCart.events.unsubscribe('cart:closed', cartClosedhandlerGuid);

    TwoCoInlineCart.events.subscribe('cart:error', function (errorData) {
      console.log('Cart error occurred:', errorData);
      // errorData will now contain the error object with the errors array
      if (errorData && errorData.errors && errorData.errors.length > 0) {
          const error = errorData.errors[0];

          if (error.code === 'GDPR_EMAIL_VALIDATION') {
              console.log('GDPR validation failed:', error.message);
              alert('Please verify your email address');
          } else if (error.code === 'BOOT_ERROR') {
              console.log('Boot error:', error.message);
              alert('Unable to initialize cart');
          }
      }
    });
  });

  window.document.getElementById('buy-button').addEventListener('click', function() {
    TwoCoInlineCart.products.add({
      code: "74B8E17CC0"
    });
    TwoCoInlineCart.cart.checkout();
  });
```

## Demo

After setting the subscribe/unsubscribe details for the InLine cart using the above methods, your cart should look like this:

{% embed url="<https://codepen.io/2checkout-documentation/pen/EByzpY>" %}


---

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