Permissions.query() - Web APIs 编辑

Experimental

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The Permissions.query() method of the Permissions interface returns the state of a user permission on the global scope.

Syntax

navigator.permissions.query(PermissionDescriptor).then(function(permissionStatus) { ... })

Parameters

PermissionDescriptor

An object that sets options for the query operation consisting of a comma-separated list of name-value pairs. The available options are:

• name: The name of the API whose permissions you want to query. An up-to-date list of permission names can be found in the spec under the PermissionName enum, but bear in mind that the actual permissions supported by browsers is currently much smaller than this. Firefox for example currently supports geolocation, notifications, push, and persistent-storage (see our Permissions.webidl file).
• userVisibleOnly: (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.
• sysex: (Midi only) Indicates whether you need and/or receive system exclusive messages. The default is false.

Note: As of Firefox 44, the permissions for Notifications and Push have been merged. If permission is granted (e.g. by the user, in the relevant permissions dialog), navigator.permissions.query() will return true for both notifications and push.

Note: The persistent-storage permission allows an origin to use a persistent box (i.e persistent storage) for its storage, as per the Storage API.

Returns

A Promise that resolves to a PermissionStatus object.

Exceptions

Example

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

Specifications

Browser compatibility

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