[RNMobile] Pass Android Fetch Responses Across the Bridge as Objects

[SiobhyB]

Description

Fetch request in Android being passed as a String, instead of an Object: https://github.com/wordpress-mobile/WordPress-Android/blob/ddb3be8823733e4d6305e63978e8f8353b7c4528/WordPress/src/main/java/org/wordpress/android/ui/posts/reactnative/ReactNativeRequestHandler.kt#L82

fetchRequest method on the JS side.

iOS

and for iOS, we seem to have an object response from here: https://github.com/wordpress-mobile/WordPressKit-iOS/blob/19a2f186ef6e08e95c4678fd2af487727f3da9a3/WordPressKit/WordPressComRestApi.swift#L203

which is passed along without unwrapping here: https://github.com/wordpress-mobile/WordPress-iOS/blob/837fbd067d0af8162fa0e21af499a4e469c50b25/WordPress/Classes/ViewRelated/Gutenberg/GutenbergNetworking.swift#L26

Things I've tried

Replicating Error Bundle

What I tried: I attempted to replicate the way data is being passed over the bridge via a bundle for the error: https://github.com/wordpress-mobile/WordPress-Android/blob/develop/WordPress/src/main/java/org/wordpress/android/ui/posts/reactnative/ReactNativeRequestHandler.kt#L56

Challenges: There doesn't appear to be an easy way to add an object to a bundle.

Possible: Look into the putParcelable method?

Using WritableMap or WritableArray to convert the string to a JsonObject

What I tried: I attempted to see whether the WritableMap helper method could be used to convert the string to a JsonObject here, including reading through multiple SO posts and tutorials: https://github.com/WordPress/gutenberg/blob/trunk/packages/react-native-bridge/android/react-native-bridge/src/main/java/org/wordpress/mobile/ReactNativeGutenbergBridge/RNReactNativeGutenbergBridgeModule.java#L303

Challenges: I wasn't able to get this working.

Possible: It's possible that my lack of experience is a blocker here and I could continue experimenting.

Passing the response as a JsonObject

What I tried: Similar to the above, but rather than using a bundle, I cast the response to a JsonObject and attempted to pass it over the bridge.

Challenges: The import com.google.gson.JsonObject; library is required, which will require gradle changes for the files that live on the Gutenberg side. I had an experiment but wasn't able to find a straightforward way to achieve this.

Possible: Ask for help from Platform around gradle changes.

How has this been tested?

Latest Posts is an example of a block that uses fetch responses in order to fetch categories. We can therefore follow these testing steps to check whether responses still work as expected on Android:

• In the Android app, navigate to the post editor. If the site doesn't already have categories, add some via the Post Settings tab.
• Add the Latest Posts block.
• Tap on the block's cog/gear icon and then tap the categories option.
• Verify that you're able to view the list of the site's categories.

Screenshots

Types of changes

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• I've tested my changes with keyboard and screen readers.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR (please manually search all *.native.js files for terms that need renaming or removal).