webRequest.StreamFilter.write()

Writes some response data to the output stream.

filter.write(
  data    // ArrayBuffer or Uint8Array
)

data

Uint8Array or ArrayBuffer: array of bytes containing the data to pass to the browser's rendering engine.

None.

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

This example uses write(), to replace "Example" in the first chunk of the response with "WebExtension Example".

function listener(details) {
  let filter = browser.webRequest.filterResponseData(details.requestId);
  let decoder = new TextDecoder("utf-8");
  let encoder = new TextEncoder();

  filter.ondata = event => {
    let str = decoder.decode(event.data, {stream: true});
    // Just change any instance of Example in the HTTP response
    // to WebExtension Example.
    str = str.replace(/Example/g, 'WebExtension Example');
    filter.write(encoder.encode(str));
    filter.disconnect();
  }

  //return {}; // not needed
}

browser.webRequest.onBeforeRequest.addListener(
  listener,
  {urls: ["https://example.com/*"], types: ["main_frame"]},
  ["blocking"]
);