expo-permissions

expo-permissions

When it comes to adding functionality that can access potentially sensitive information on a user's device, such as their location, or possibly send them possibly unwanted push notifications, you will need to ask the user for their permission first. Unless you've already asked their permission, then no need. And so we have the Permissions module.

If you are deploying your app to the Apple iTunes Store, you should consider adding additional metadata to your app in order to customize the system permissions dialog and explain why your app requires permissions. See more info in the App Store Deployment Guide.

Installation

If your app is running in Expo then everything is already set up for you, just import { Permissions } from 'expo';

Otherwise, you need to install the package from npm registry.

yarn add expo-permissions or npm install expo-permissions

Also, make sure that you have expo-core installed, as it is required by expo-permissions to work properly.

iOS

Add these dependencies to your Podfile:

pod 'EXPermissions', path: '../node_modules/expo-permissions/ios'
pod 'EXPermissionsInterface', path: '../node_modules/expo-permissions-interface/ios'

and run pod install under the parent directory of your Podfile.

Android

1. Append the following lines to android/settings.gradle:

   include ':expo-permissions'
   project(':expo-permissions').projectDir = new File(rootProject.projectDir, '../node_modules/expo-permissions/android')
   

   and if not already included

   include ':expo-permissions-interface'
   project(':expo-permissions-interface').projectDir = new File(rootProject.projectDir, '../node_modules/expo-permissions-interface/android')
   

2. Insert the following lines inside the dependencies block in android/app/build.gradle:

   compile project(':expo-permissions')
   

   and if not already included

   compile project(':expo-permissions-interface')
   

3. Add new PermissionsPackage() to your module registry provider in MainApplication.java.

Methods

Expo.Permissions.getAsync(...permissionTypes)

Determines whether your app has already been granted access to the provided permissions types.

Arguments

• permissionTypes (string) -- The names of the permissions types.

Returns

Returns a Promise that is resolved with the information about the permissions, including status, expiration and scope (if it applies to the permission type). Top-level status and exprires keys stores combined info of each component permission that is asked for. If any permission resulted in negative result than that negative result is propagated here, that means top-level values are positive only if all component values are positive.

Examples [...componentsValues] => topLevelStatus:

• [granted, denied, granted] => denied
• [granted, granted, granted] => granted

{
  status, // combined status of all component permissions being asked for, if any of has status !== 'granted' then that status is propagated here
  expires, // combined expires of all permissions being asked for, same as status
  permissions: { // an object with an entry for each permission requested
    [Permissions.TYPE]: {
      status,
      expires,
      ... // any additional permission-specific fields
    },
    ...
  },
}

Example

async function alertIfRemoteNotificationsDisabledAsync() {
  const { Permissions } = Expo;
  const { status } = await Permissions.getAsync(Permissions.NOTIFICATIONS);
  if (status !== 'granted') {
    alert('Hey! You might want to enable notifications for my app, they are good.');
  }
}

async function checkMultiPermissions() {
  const { Permissions } = Expo;
  const { status, expires, permissions } = await Permissions.getAsync(Permissions.CALENDAR, Permissions.CONTACTS)
  if (status !== 'granted') {
    alert('Hey! You heve not enabled selected permissions');
  }
}

Expo.Permissions.askAsync(...types)

Prompt the user for types of permissions. If they have already granted access, response will be success.

Arguments

• types (string) -- The names of the permissions types.

Returns

Same as for Permissions.getAsync

Example

async function getLocationAsync() {
  const { Location, Permissions } = Expo;
  const { status } = await Permissions.askAsync(Permissions.LOCATION);
  if (status === 'granted') {
    return Location.getCurrentPositionAsync({enableHighAccuracy: true});
  } else {
    throw new Error('Location permission not granted');
  }
}

Permissions types

Permissions.NOTIFICATIONS

The permission type for user-facing notifications and remote push notifications.

Note: On iOS, asking for this permission asks the user not only for permission to register for push/remote notifications, but also for showing notifications as such. At the moment remote notifications will only be received when notifications are permitted to play a sound, change the app badge or be displayed as an alert. As iOS is more detailed when it comes to notifications permissions, this permission status will contain not only status and expires, but also Boolean values for allowsSound, allowsAlert and allowsBadge.

Note: On iOS, this does not disambiguate undetermined from denied and so will only ever return granted or undetermined. This is due to the way the underlying native API is implemented.

Note: Android does not differentiate between permissions for local and remote notifications, so status of permission for NOTIFICATIONS should always be the same as the status for USER_FACING_NOTIFICATIONS.

Permissions.USER_FACING_NOTIFICATIONS

The permission type for user-facing notifications. This does not register your app to receive remote push notifications; see the NOTIFICATIONS permission.

Note: iOS provides more detailed permissions, so the permission status will contain not only status and expires, but also Boolean values for allowsSound, allowsAlert and allowsBadge.

Note: Android does not differentiate between permissions for local and remote notifications, so status of permission for USER_FACING_NOTIFICATIONS should always be the same as the status for NOTIFICATIONS.

Permissions.LOCATION

The permission type for location access.

Permissions.CAMERA

The permission type for photo and video taking.

Permissions.AUDIO_RECORDING

The permission type for audio recording.

Permissions.CONTACTS

The permission type for reading contacts.

Permissions.CAMERA_ROLL

The permission type for reading or writing to the camera roll.

Permissions.CALENDAR

The permission type for reading or writing to the calendar.

Permissions.REMINDERS

The permission type for reading or writing reminders (iOS only).

Expo.Permissions.SYSTEM_BRIGHTNESS

The permissions type for changing brighness of the screen

Android: permissions equivalents inside app.json

If you specified android.permissions inside your app.json (read more about configuration) you have to use values corresponding to their Expo.Permissions equivalents.

Expo	Android
LOCATION	ACCESS_COARSE_LOCATION, ACCESS_FINE_LOCATION
CAMERA	CAMERA
AUDIO_RECORDING	RECORD_AUDIO
CONTACTS	READ_CONTACTS
CAMERA_ROLL	READ_EXTERNAL_STORAGE, WRITE_EXTERNAL_STORAGE
CALENDAR	READ_CALENDAR, WRITE_CALENDAR