Make OneSignalId and ExternalId nullable for Android

[jinliu9508]

Description

One Line Summary

Make OneSignalId and ExternalId nullable for Android. The result of calling the getter will be null if no ID is currently available.

Details

Motivation

To keep all wrappers consistent when dealing with the IDs.

Testing

Manual testing

I have modified the example scene so that it displays "null" if calling the ID getter results in a null string. Tested on Android emulator pixel 3a API 34

Affected code checklist

• Notifications
  • Display
  • Open
  • Push Processing
  • Confirm Deliveries
• Outcomes
• Sessions
• In-App Messaging
• REST API requests
• Public API changes

Checklist

Overview

• I have filled out all REQUIRED sections above
• PR does one thing
  • If it is hard to explain how any codes changes are related to each other then it most likely needs to be more than one PR
• Any Public API changes are explained in the PR details and conform to existing APIs

Testing

• I have included test coverage for these changes, or explained why they are not needed
• All automated tests pass, or I explained why that is not possible
• I have personally tested this on my device, or explained why that is not possible

Final pass

• Code is as readable as possible.
  • Simplify with less code, followed by splitting up code into well named functions and variables, followed by adding comments to the code.
• I have reviewed this PR myself, ensuring it meets each checklist item
  • WIP (Work In Progress) is ok, but explain what is still in progress and what you would like feedback on. Start the PR title with "WIP" to indicate this.

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This change is 

[shepherd-l]

Lgtm!

I think the editor platform methods could also return null because the subscription doesn't get created on the backend. What do you think? Do you have an preferences?
https://github.com/OneSignal/OneSignal-Unity-SDK/blob/user-model/main/com.onesignal.unity.core/Editor/Platform/UserManager.cs#L35

[nan-li]

Is this also addressed for the UserState object? {"onesignalId": "123456789, "externalId": null}

[jinliu9508]

Lgtm!

I think the editor platform methods could also return null because the subscription doesn't get created on the backend. What do you think? Do you have an preferences? https://github.com/OneSignal/OneSignal-Unity-SDK/blob/user-model/main/com.onesignal.unity.core/Editor/Platform/UserManager.cs#L35

Ok I just made that change. I think it will keep the code consistent regarding the default value of the IDs.

[jinliu9508]

Is this also addressed for the UserState object? {"onesignalId": "123456789, "externalId": null}

Yes, both null and "" will make the getter to return null.

[nan-li]

Is this also addressed for the UserState object? {"onesignalId": "123456789, "externalId": null}

Yes, both null and "" will make the getter to return null.

For the UserState that is passed to observers? I am not sure how everything is translated across Unity bridges, but here it uses the jsonRepresentation method which returns empty strings. Does it later translate to null in another layer?

[jinliu9508]

Is this also addressed for the UserState object? {"onesignalId": "123456789, "externalId": null}

Yes, both null and "" will make the getter to return null.

For the UserState that is passed to observers? I am not sure how everything is translated across Unity bridges, but here it uses the jsonRepresentation method which returns empty strings. Does it later translate to null in another layer?

Unity string is nullable and yes this line of code string.IsNullOrEmpty(id)? null : id; later translate the string to null for either empty or null string from the native.

[nan-li]

Unity string is nullable and yes this line of code string.IsNullOrEmpty(id)? null : id; later translate the string to null for either empty or null string from the native.

Ok! 👍🏼 Thanks! I did not know that also applied to the UserState