Permissions: query() method

permissionDescriptor

An object that sets options for the query operation. The available options for this descriptor depend on the permission type.

All permissions have a name:

name

A string containing the name of the API whose permissions you want to query, such as camera, bluetooth, microphone, geolocation (see Permissions for a more complete list). The returned Promise will reject with a TypeError if the permission name is not supported by the browser.

For the push permissions you can also specify:

userVisibleOnly Optional

(Push only, not supported in Firefox — see the Browser Support section below) Indicates whether you want to show a notification for every message or be able to send silent push notifications. The default is false.

For the midi permission you can also specify:

sysex Optional

Indicates whether you need and/or receive system exclusive messages. The default is false.

A Promise that resolves to a PermissionStatus object.

InvalidStateError DOMException

Thrown if query() method is invoked in the browsing context and its associated document is not fully active.

TypeError

Thrown if retrieving the PermissionDescriptor information failed in some way, or the permission doesn't exist or is unsupported by the user agent.

This example shows how you might display news related to the current location if the geolocation permission is granted, and otherwise prompt the user to enable granting access to the location.

navigator.permissions.query({ name: "geolocation" }).then((result) => {
  if (result.state === "granted") {
    showLocalNewsWithGeolocation();
  } else if (result.state === "prompt") {
    showButtonToEnableLocalNews();
  }
  // Don't do anything if the permission was denied.
});

This example shows the result of querying each of the permissions.

The code uses navigator.permissions.query() to query each permission, logging either the permission status or the fact that the permission is not supported on the browser. Note that the query() is called inside a try...catch block because the associated Promise will reject if the permission is not supported.

<pre id="log"></pre>

const logElement = document.querySelector("#log");
function log(text) {
  logElement.innerText = `${logElement.innerText}${text}\n`;
  logElement.scrollTop = logElement.scrollHeight;
}

#log {
  height: 320px;
  overflow: scroll;
  padding: 0.5rem;
  border: 1px solid black;
}

// Array of permissions
const permissions = [
  "accelerometer",
  "accessibility-events",
  "ambient-light-sensor",
  "background-sync",
  "camera",
  "clipboard-read",
  "clipboard-write",
  "geolocation",
  "gyroscope",
  "local-fonts",
  "magnetometer",
  "microphone",
  "midi",
  "notifications",
  "payment-handler",
  "persistent-storage",
  "push",
  "screen-wake-lock",
  "storage-access",
  "top-level-storage-access",
  "window-management",
];

processPermissions();

// Iterate through the permissions and log the result
async function processPermissions() {
  for (const permission of permissions) {
    const result = await getPermission(permission);
    log(result);
  }
}

// Query a single permission in a try...catch block and return result
async function getPermission(permission) {
  try {
    const result = await navigator.permissions.query({ name: permission });
    return `${permission}: ${result.state}`;
  } catch (error) {
    return `${permission} (not supported)`;
  }
}

The log from running the code is shown below: