Modifying Permissions in Your iOS App

Certain features in PSPDFKit need additional permissions, which will require modifications in your Info.plist file. Adding these descriptive keys has been a recommendation since iOS 7 and this has been strongly enforced since iOS 10. When the system prompts the user to allow access for a certain subsystem, the value of the permission key will be displayed as part of the alert. From the Apple documentation:

Important: To protect user privacy, an iOS app linked on or after iOS 10.0, and which accesses TYPE, must statically declare the intent to do so. Include the KEY in your app’s Info.plist file and provide a purpose string for this key. If your app attempts to access TYPE without a corresponding purpose string, your app exits.

These rules are enforced statically at upload time in App Store Connect. The static code analyzer can’t detect whether or not the code is being used, so the descriptions for NSCameraUsageDescription or NSMicrophoneUsageDescription need to be added when linked with PSPDFKit, even if you don’t allow image or sound annotation creation. The description isn’t visible to the user; therefore, if you don’t use this anywhere in your app, you can use something generic.

Learn more in Apple’s Technical Q&A QA1937: Resolving the Privacy-Sensitive Data App Rejection.

Microphone Permissions

Creating sound annotations requires that you set the NSMicrophoneUsageDescription key in your Info.plist file. This has been recommended since iOS 7 and enforced since iOS 10.

If you don’t set this, the application will crash with the following error log:

[access] This app has crashed because it attempted to access privacy-sensitive data without a usage description.  The app’s Info.plist must contain an NSMicrophoneUsageDescription key with a string value explaining to the user how the app uses this data.

To fix this, edit your Info.plist file and assign a descriptive string to this key. PSPDFKit has been checking for this since 5.5.1 to warn you in advance if you forget. See our sample projects for examples of such descriptions.

Apple statically checks for certain audio APIs, such as AVAudioRecorder. Using this class is enough to require the microphone permissions, even when this code path is never executed. The implication is that even when sound annotations are completely disabled, this string must be set to pass the static App Store check. In such a case, keep the description string generic. If the review team follows up and asks what this is for, you can reference this page and explain that there’s only one statically compiled binary of the PSPDFKit SDK, and the functionality is implemented but dormant. Permissions only appear in Settings once they’ve been requested, so the user won’t see these permissions in the Settings app.

ℹ️ Note: Audio recording isn’t available in extension contexts, so this option will always be filtered out.

It’s also recommended to add “audio” to the UIBackgroundModes key to allow sound recording in the background. See Apple QA1668 for more details.

App Store Considerations

Apple might request information about how it can test UIBackgroundModes — simply attach a sample PDF that contains a sound annotation (page 17) to this request. The file provided here contains copyright-free sample music and can be used to test sound annotations. Just make sure you don’t accidentally disable sound annotations by excluding them from Document.renderAnnotationTypes.

Image Permissions

Creating image annotations (stamps) using the camera requires the NSCameraUsageDescription key. Saving images requires NSPhotoLibraryAddUsageDescription.

Browser Permissions

If you use WKWebView (e.g. via WebsiteLinkAnnotationEditingViewController for the link annotation editing UI, or via WebViewController), you might want to set NSAllowsArbitraryLoadsInWebContent to YES to allow both HTTP links and HTTPS pages that don’t yet comply with Apple’s App Transport Security (ATS) rules to be loaded.

Putting It All Together

Your Info.plist file should have following entries:

<string>Recording sound annotations requires the microphone.</string>
<string>Pictures captured with the camera can be added to the document as image annotations.</string>
<string>Images from documents and annotations can be saved to the photo library.</string>