PaymentResponse: complete() method
==================================

**Secure context:** This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

 The `PaymentRequest` method
 **`complete()`** of the Payment Request API notifies the
 user agent that the user interaction is over, and causes any remaining
 user interface to be closed.

 This method must be called after the user accepts
 the payment request and the `Promise` returned by the
 `PaymentRequest.show()` method is resolved.

Syntax
------


```js
complete()
complete(result)
```

### Parameters

`result` Optional

 A string indicating the state of the payment operation upon
 completion. It must be one of the following:


`success`

 The payment was successfully processed. The user agent may or may not present
 some form of "payment successful" indication to the user.


`fail`

 The payment was not successfully processed. The failure may or may not be
 announced to the user by the user agent, depending on its design.


`unknown`

 The success or failure status of the transaction is unknown or irrelevant, and
 the user agent should not present any notification, even if it normally would.
 *This is the default value.*


**Note:** In older versions of the specification, an empty string,
 `""`, was used instead of `unknown` to indicate a completion
 without a known result state. See the Browser compatibility section
 below for details.


### Return value

 A `Promise` which resolves with no input value once the payment interface
 has been fully closed. If an error occurs, the promise instead rejects, returning one of
 the exceptions listed below.

### Exceptions

`AbortError` `DOMException`

 Returned if the document in which the payment request is taking place became inactive while the
 user interface was shown.


`InvalidStateError` `DOMException`

 Returned if the payment has already completed, or `complete()` was called while a
 request to retry the payment is pending. You can't treat a payment as complete after
 requesting that the payment be tried again.


Examples
--------

 The following example sends payment information to a secure server using the Fetch API. It
 calls `complete()` with an answer appropriate to the status in the response.


```js
// Initialization of PaymentRequest arguments are excerpted for the
// sake of brevity.
const payment = new PaymentRequest(supportedInstruments, details, options);

payment
  .show()
  .then((paymentResponse) => {
    const fetchOptions = {
      method: "POST",
      credentials: include,
      body: JSON.stringify(paymentResponse),
    };
    const serverPaymentRequest = new Request("secure/payment/endpoint");
    fetch(serverPaymentRequest, fetchOptions)
      .then((response) => {
        if (response.status < 400) {
          paymentResponse.complete("success");
        } else {
          paymentResponse.complete("fail");
        }
      })
      .catch((reason) => {
        paymentResponse.complete("fail");
      });
  })
  .catch((err) => {
    console.error("Uh oh, something bad happened", err.message);
  });
```

Specifications
--------------

| Specification |
| --- |
| Payment Request API 1.1 # dom-paymentresponse-complete |

Browser compatibility
---------------------

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