Response: formData() method

{{APIRef("Fetch API")}}{{AvailableInWorkers}}

The formData() method of the {{domxref("Response")}} interface takes a {{domxref("Response")}} stream and reads it to completion. It returns a promise that resolves with a {{domxref("FormData")}} object.

[!NOTE] This is mainly relevant to service workers. If a user submits a form and a service worker intercepts the request, you could for example call formData() on it to obtain a key-value map, modify some fields, then send the form onwards to the server (or use it locally).

Syntax

formData()

Parameters

None.

Return value

A {{jsxref("Promise")}} that resolves with a {{domxref("FormData")}} object.

Exceptions

• AbortError {{domxref("DOMException")}}
  • : The request was aborted.
• {{jsxref("TypeError")}}
  • : Thrown for one of the following reasons:
    • The response body is disturbed or locked.
    • There was an error decoding the body content (for example, because the {{httpheader("Content-Encoding")}} header is incorrect).
    • The {{glossary("MIME")}} type of the body cannot be determined from the {{httpheader("Content-Type")}} headers included in the response, or is not application/x-www-form-urlencoded or multipart/form-data.
    • The body cannot be parsed as a FormData object.

Examples

TBD.

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• ServiceWorker API
• HTTP access control (CORS)
• HTTP