I have a class like class

someClass(val id : String, val imageResourceId: Int)

. Basically I want to set the drawable id as the source of the image resource to show in the app. However, resIds may change upon adding new resources so I end up with a database which hosts wrong ids. One way I can think of is adding the icons in the

assets

folder and user Glide to load from there. Any other thoughts?

Have you tried this api? https://developer.android.com/reference/android/content/res/Resources.html#getIdentifier(java.lang.String,%20java.lang.String,%20java.lang.String) You could store the resource name instead?

But why do you worry about Id changes, Android automatically generate all of them in R.class, so you can use this fields directly and do not worry that I'd will be changed

@gildor From what I understood, the generated ID is being stored. When the build changes the id, the ones in the DB become stale

Indeed, I may store the resource name, but then each time I need it, I need to search it.

@Alin B. Sorry - Not sure I understand the concern.

I mean each time I want to display it I need to do

resources.getIdentifier(name, "drawable", "your.package.name")

Just cache it, if you need this many times, I still not completely understand your case

I am at the point of deciding how to store the value. To better put let me add another example table categories with id, name and icon. The icon is included in the app and I need to decide what to store in the icon field.

To store value in database?

other way is to put it in

assets

and load it with glide `"file:///android_asset/ic_category_one.jpg"

I would rather use some custom id for icon and map it to actual reaource on runtime

^I was thinking the same thing but it can be annoying to maintain something like that.

I would just save this id in database and map this id to actual resource like: when(iconId) { "home" -> R.drawable.ic_home_red_24dp }

but in this case I could use

when (category.name)

, no?

Otherwise you can one day decide to change icon (like on ic_dead_star_black_36dp, and of course you want to have proper name for icon not some hardcoded one

so maybe have a get() for imageResId which has a when based on the

name

To be honest I don't think it's too much tedious, depends on amount of icons of course

I don't anymore if I go with your approach, just a getter to return the drawable id I want based on the name

Again, depends on case, for example we have emoju drawables and of course we do not map them all, but we use unicode id of emoji to generate resource I'd and llokup by name

I am talking about a few icons, 5 maybe. To be sure understand you right, have something like

class Category(val id:Int, val name, val imageResId:Int){
    val imageResId:Int
	get()=when(...)
}

If categories are not dynamic, just use enum for category and serialize it as enum name, will be type safe, declarative and flexible Also no need to serialize all unnecessary data to database if you already declare it

ok, digging enum in kotlin... everything is new to me. This:

enum class Category(val name:String){
    HOME("home"),
    WORK("work")
}

Yes, and also property for icon

This is a really great answer. Thank you very much!

Kotlin enums implementation almost identical to java, so no real difference

How about for a scenario where I have products and the user can pick a generic icon from a set of icons to a new added product. In this case I need to store something in the database as I insert the product

Also one more good thing about enums is that you can get a full list of possible options and for example iterate them

I did a little coding to get a hold of the idea, here is how I think it could be

enum class CategoryType(val id: String, val imageResId: Int) {
    HOME("home", R.id.ic_home),
    WORK("work", R.id.ic_work)
}

then when I use it

val categoryType = CategoryType.valueOf(item.dbCategoryValue)

val imageResIdToLoad = categoryType.imageResId

Could you get away with not using the id param instead?

enum class CategoryType(val id: Int) {
        HOME(R.id.ic_home),
        WORK(R.id.ic_work)
    }
CategoryType.valueOf("HOME").id

That what I said above, the id seemed not needed

Ah sorry!

No need to, thanks for the code sample.

Happy to help

Also if you use some mapper of db to objects, you can just use enums, probably your mapper can do that automatically. You mentioned Room in one of other threads, you can use enums with room without manual unwrapping them from string

Yeah I am using Room

Sure

Awesome, thank you very much for you help.