Introduction

In the realm of iOS development, handling application lifecycle events and user interactions efficiently is crucial. One of the errors developers may encounter is related to handling specific actions incorrectly. In this context, the error `_handleNonLaunchSpecificActions` often appears in iOS9. This article delves into the technical aspects of this error, providing examples, possible causes, and solutions to navigate this challenge.

Understanding `NSError` in iOS

Before diving into the specific error, it's essential to have a basic understanding of how errors are managed in iOS. Objective-C and Swift offer error handling through the `NSError` class or the `Error` protocol, respectively. These mechanisms are employed to enable error propagation and handling within applications. The error in question, `_handleNonLaunchSpecificActions`, stems from these mechanisms when certain expectations in the app's logic aren't met.

The `_handleNonLaunchSpecificActions` Error: Explanation

Technical Origins

The `_handleNonLaunchSpecificActions` error appears when an iOS application attempts to handle user actions that are not directly related to the initial launch of the app. This can happen, for instance, when attempting to handle notifications or deep links improperly. Such situations can arise during cold starts or when the app was previously terminated and is now being relaunched to handle specific user actions.

Common Scenarios Leading to This Error

1. Cold Start Handling:
   • During a cold start, if the application handles an event (like a remote notification) without properly checking the launch state, it may lead to this error. This is because the application should have distinct pathways for handling launch versus non-launch actions.
2. Deep Linking:
   • When an application does not properly configure or handle a deep link and attempts to perform navigation actions prematurely, it might run into this error.
3. State Restoration:
   • Failing to restore the previous state of the app correctly or attempting to perform non-launch related actions before restoration can trigger this error.

Example Scenario

Consider an app that utilizes remote notifications. When a user taps a notification, it attempts to trigger a specific view in the application. If the app is not correctly launched at this point, trying to present a view controller directly can result in `_handleNonLaunchSpecificActions`.