Declare app permissions

As mentioned in the workflow for using permissions, if your app requests app permissions, you must declare these permissions in your app's manifest file. These declarations help app stores and users understand the set of permissions that your app might request.

The process of performing a permission request depends on the type of permission:

• If the permission is an install-time permission, such as a normal permission or a signature permission, the permission is granted automatically at install time.
• If the permission is a runtime permission, and if your app is installed on a device that runs Android 6.0 (API level 23) or higher, you must request the permission yourself.

Add declaration to app manifest

To declare a permission that your app might request, include the appropriate <uses-permission> element in your app's manifest file. For example, an app that needs to access the camera would have this line in the manifest:

AndroidManifest.xml

<manifest ...>
    <uses-permission android:name="android.permission.CAMERA"/>
    <application ...>
        ...
    </application>
</manifest>

Declare hardware as optional

Some permissions, such as CAMERA, allow your app to access pieces of hardware that only some Android devices have. If your app declares one of these hardware-associated permissions, consider whether your app cannot run at all on a device that doesn't have that hardware. In most cases, hardware is optional, so it's better to declare the hardware as optional by setting android:required to false in your <uses-feature> declaration, as shown in the following code snippet:

AndroidManifest.xml

<manifest ...>
    <application>
        ...
    </application>
    <uses-feature android:name="android.hardware.camera"
                  android:required="false" />
<manifest>

Determine hardware availability

If you declare hardware as optional, it's possible for your app to run on a device that doesn't have that hardware. To check whether a device has a specific piece of hardware, use the hasSystemFeature() method, as shown in the following code snippet. If the hardware isn't available, gracefully disable that feature in your app.

// Check whether your app is running on a device that has a front-facing camera.
if (applicationContext.packageManager.hasSystemFeature(
        PackageManager.FEATURE_CAMERA_FRONT)) {
    // Continue with the part of your app's workflow that requires a
    // front-facing camera.
} else {
    // Gracefully degrade your app experience.
}

// Check whether your app is running on a device that has a front-facing camera.
if (getApplicationContext().getPackageManager().hasSystemFeature(
        PackageManager.FEATURE_CAMERA_FRONT)) {
    // Continue with the part of your app's workflow that requires a
    // front-facing camera.
} else {
    // Gracefully degrade your app experience.
}

Declare permissions by API level

To declare a permission only on devices that support runtime permissions—that is, devices that run Android 6.0 (API level 23) or higher—include the uses-permission-sdk-23 element instead of the uses-permission element.

When using either of these elements, you can set the maxSdkVersion attribute. This attribute indicates that devices running a higher version than maxSdkVersion don't need a particular permission.