webRequest.StreamFilter.onstop

An event handler that will be called when the stream has no more data to deliver. In the event handler you can still call filter functions such as write(), disconnect(), or close().

Browser compatibility

BCD tables only load in the browser

Examples

This example will append "extra stuff" to the response:

function listener(details) {
  const filter = browser.webRequest.filterResponseData(details.requestId);
  const encoder = new TextEncoder();

  filter.ondata = (event) => {
    // pass through all the response data
    filter.write(event.data);
  };

  filter.onstop = (event) => {
    filter.write(encoder.encode("extra stuff"));
    filter.disconnect();
  };
}

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

Here's another version of the example above:

function listener(details) {
  const filter = browser.webRequest.filterResponseData(details.requestId);
  const encoder = new TextEncoder();

  const data = [];
  filter.ondata = (event) => {
    data.push(event.data);
  };

  filter.onstop = (event) => {
    for (const buffer of data) {
      filter.write(buffer);
    }
    filter.write(encoder.encode("extra stuff"));
    filter.close();
  };
}

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