extensibility.md

Extensibility

This document describes how the Permissions API can be used to express more complex permissions than the one currently specified and how it should be used by other specifications.

Permission description

dictionary PermissionDescriptor {
  required PermissionName name;
};

PermissionDescriptor is a dictionary that describes a permission. Its minimal content is a permission name but complex permissions can be described by more than a name. Such permissions should inherit from it and extend it.

Simple permissions

geolocation and notifications do not require more options for now. So their usage only require passing a PermissionDescriptor with a name.

Quota API

Quota API will need options because it is more granular than accepted/denied:

dictionary QuotaPermissionDescriptor : PermissionDescriptor {
  required unsigned long long quota;
           StorageType type;
};

Checking quota permission would look like:

navigator.permissions.query({name: 'quota', quota: '1024', type: 'persistent' }).then(function(status) {
  if (status.status == 'denied') {
    navigator.permissions.query({name:'quotar', quota: '512', type: 'persistent' }).then(ellipsis);
  }
});

GetUserMedia

Capture has basically two permissions: audio and video. There are a couple of ways to design this.

Have one permission with two booleans

dictionary CapturePermissionDescriptor : PermissionDescriptor {
  required boolean audio;
  required boolean video;
};

But it might be odd if audio and video are both set to false. Though, technically, the permission should definitely be granted.

Have an enum for the tri-state

enum CapturePermissionType {
  "audio",
  "video",
  "audio-video"
}
dictionary CapturePermissionDescriptor : PermissionDescriptor {
  required CapturePermissionType type;
};

Have two permissions

Simply capture-video and capture-audio.

Geolocation extended

The Geolocation specification defines a boolean called enableHighAccuracy. Some user agents could have a permissions behaviour depending on that value. We could imagine that the geolocation permission could be extended to include this boolean in the future:

dictionary GeolocationPermissionDescriptor : PermissionDescriptor {
  boolean enableHighAccurary = true;
};