Request: textStream() method

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

The textStream() method of the {{domxref("Request")}} interface returns a {{domxref("ReadableStream")}} that can be used to read the contents of the request body in chunks of UTF-8.

This provides an easier mechanism for streaming the request body than piping the {{domxref("Request.body")}} byte stream through a {{domxref("TextDecoderStream")}}.

[!NOTE] If invoked on a Request with a null body, for example a {{httpmethod("GET")}} request, textStream() will return a valid empty stream.

Syntax

textStream()

Parameters

None.

Return value

A {{domxref("ReadableStream")}}.

Exceptions

• {{jsxref("TypeError")}}
  • : Thrown if the request body is disturbed or locked.

Examples

Reading request body content as a text stream

This example shows how to read a request body as a text stream.

We create a sample Request, obtain a ReadableStream of its body using textStream(), then read the text via a reader created using {{domxref("ReadableStream.getReader()")}}.

const pElem = document.querySelector("p");

const req = new Request("https://example.com", {
  method: "POST",
  body: '{"hello": "world"}',
});

async function streamRequestText(request) {
  const textStream = request.textStream();
  // instead of
  // const textStream = request.body.pipeThrough(new TextDecoderStream());

  const reader = textStream.getReader();

  while (true) {
    const { value, done } = await reader.read();
    if (done) break;
    pElem.textContent += value;
  }
}

streamRequestText(req);

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("ReadableStream")}}
• {{domxref("ReadableStream.getReader()")}}
• {{domxref("Response.body")}}
• {{domxref("Response.textStream()")}}