NativeScript for Mobile App Development State Management and Application Architecture 2

Question 1

In NativeScript with Angular, what decorator is used to create a service that holds shared application state?

Accepted Answer

@Injectable

Answer

@Injectable marks a class as available for Angular's dependency injection system, enabling it to be shared as a state container across components.

Question 2

How does NativeScript's Observable.set() method differ from directly assigning a property value?

Accepted Answer

set() triggers propertyChange notifications, direct assignment does not

Answer

Observable.set() updates the property AND fires the propertyChange event so bound UI elements update automatically, unlike silent direct property assignment.

Question 3

Which architectural approach is most suitable for large NativeScript applications that need predictable state changes?

Accepted Answer

Flux/Redux unidirectional data flow

Answer

Flux/Redux's unidirectional data flow (action → reducer → store → view) makes state changes predictable and traceable in large applications.

Question 4

In NativeScript, what is the recommended way to handle asynchronous operations like API calls within a ViewModel?

Accepted Answer

Using Promises or async/await and updating Observable properties on completion

Answer

Promises and async/await keep network calls off the UI thread, and updating Observable properties on completion automatically refreshes the bound UI.

Question 5

What happens to application state stored only in memory when a NativeScript app is sent to the background on iOS?

Accepted Answer

It may be lost if the OS terminates the app to free memory

Answer

iOS may terminate background apps to reclaim memory, causing any in-memory-only state to be lost — persistent storage must be used for critical data.

NativeScript for Mobile App Development Practice Test

NativeScript for Mobile App Development Practice Test

NativeScript for Mobile App Development State Management and Application Architecture 2