TextResource

TextResource.kt

import android.content.res.Resources
import androidx.annotation.PluralsRes
import androidx.annotation.StringRes

// from https://hannesdorfmann.com/abstraction-text-resource/
sealed class TextResource {
    companion object {
        // Just needed for static method factory so that we can keep concrete implementations file private
        fun fromText(text: String): TextResource = SimpleTextResource(text)

        fun fromStringId(@StringRes id: Int, vararg formatArgs: Any): TextResource =
            IdTextResource(id, formatArgs.toList())

        fun fromPlural(@PluralsRes id: Int, quantity: Int, vararg formatArgs: Any): TextResource =
            PluralTextResource(id, quantity, formatArgs.toList())
    }
}

private data class SimpleTextResource(
    val text: String
) : TextResource()

private data class IdTextResource(
    @StringRes val id: Int,
    val formatArgs: List<Any?>?,
) : TextResource()

private data class PluralTextResource(
    @PluralsRes val pluralId: Int,
    val quantity: Int,
    val formatArgs: List<Any>
) : TextResource()

@Suppress("SpreadOperator")
fun TextResource.asString(resources: Resources): String = when (this) {
    is SimpleTextResource -> this.text
    is IdTextResource -> {
        if (formatArgs == null) {
            resources.getString(this.id)
        } else {
            resources.getString(this.id, *formatArgs.map { it }.toTypedArray())
        }
    }
    is PluralTextResource -> resources.getQuantityString(
        this.pluralId,
        this.quantity,
        *formatArgs.toTypedArray()
    ) 
}