[media-library] Refactor to Kotlin 4 - Asset management

[barthap]

Why, How etc...

See #14562 description for details.

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This is part of a PR stack:

1. [media-library] Refactor to Kotlin 1 - Base module #14562
2. [media-library] Refactor to Kotlin 2 - Albums #14563
3. [media-library] Refactor to Kotlin 3 - Album migration #14564
4. This PR - rewritten asset-related stuff to Kotlin, extracted it to expo.modules.medialibrary.assets package
5. [media-library] Refactor to Kotlin 5 - Utilities #14566
6. Coroutines + refactor error handling (No PR yet)

[mstach60161]

👍

[mstach60161]

Why name isn't null safe?

[barthap]

result of MediaLibraryConstants not being kotlinized yet. They're constants defined here

[lukmccall]

Great job 🔥

[kkafar]

Looks good!

[kkafar]

I believe you can achieve this functionality with built-in as? operator. As documentation is rather laconic, I looked up some cases in playground

[barthap]

Yeah, totally forgot about existence of as? operator 😅

What do you think - which one looks better?

// I have to add parenthesis here
(input["createdAfter"] as? Number)?.let {

or

input["createdAfter"].takeIfInstanceOf<Number>()?.let {

If we'd like to leave takeIfInstanceOf, then I could just replace:

Suggested change

	/**
	* If the receiver is instance of `T`, returns the receiver, otherwise returns `null`
	*/
	inline fun <reified T> Any?.takeIfInstanceOf(): T? = if (this is T) this else null
	/**
	* If the receiver is instance of `T`, returns the receiver, otherwise returns `null`
	*/
	inline fun <reified T> Any?.takeIfInstanceOf(): T? = this as? T

[lukmccall]

Yes, you can. However, I don't like it. From my perspective is less readable.

For example instead of writing:

input["first"].takeIfInstanceOf<Number>()?.toInt() ?: 20

you will have to do:

(input["first"] as? Number)?.toInt() ?: 20

And I know, it's less character... but you have added ugly brackets.

From the perspective of underlying code is doing the same thing. Safe cast operator compiles to something like this:

Any temp = value;
if (!(temp is T)) {
    temp = null;
}
T output = (T) temp;

[barthap]

Ok, I've decided the following:

• When there is a method chaining, e.g. input["first"].takeIfInstanceOf<Number>()?.toInt()?.let { ... }, I've left the takeIfInstanceOf - the reason is that I don't like these parentheses too.
  Hypotethic situation, when this approach has a huge advantage:

  // everything goes in clean, readable order
  val x = input["a"]
                ?.takeIfInstanceOf<Bundle>()
                ?.get("b")
                ?.takeIfInstanceOf<String>()
                ?.let { ... }
  
  // maybe shorter, but I got lost with parentheses
  val y = ((input["a"] as? Bundle)?.get("b") as? String)?.let { ... }

• When there's no such chaining, I replaced the occurrences with the as? operator - in such cases it's much cleaner:

  val sortBy = input["sortBy"] as? List<*>

I also updated the description of the takeIfInstanceOf method - added an example similar to the above

Anyway, nice catch, thanks for this suggestion 😁

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