How can I loop over an array of sets/maps with varying data types - kotlin

Question

I want to make it so that I keep my code dry and create 3 (or more, or less) buttons with somewhat the same structure. So I create a list of objects to loop over and put the data inside the object to use in several places in the AppButton.
I might think a bit too Pythonic, because that's my main language and I only recently started using Kotlin. What I normally do in Python:
app_buttons = [
dict(
text="....",
icon="....",
uri_string="....",
),
...
]
I've tried something similar in Kotlin with mapOf:
val appButtons = arrayOf(
mapOf(
"title" to getString(R.string.app_btn_example1),
"icon" to R.drawable.ic_some_icon_1_64,
"uriString" to "myapp://example1",
),
...
)
and then loop over them and getting from the map:
for (entry in appButtons) {
buttons.add(
AppButton(
entry.get("text"),
entry.get("icon"),
) {
val intent = Intent(Intent.ACTION_VIEW, Uri.parse(entry.get("uriString"))).apply {
val name = getString(R.string.saved_account_key)
putExtra(name, sharedPref.getString(name, null))
}
startActivity(intent)
}
)
}
But then I get Type mismatch. Required String. Found {Comparable & java.io.Serializable}?. I don't know what types to put where...
Ok different approach, using setOf and destructuring:
val appButtons = arrayOf(
setOf(
getString(R.string.app_btn_example1),
R.drawable.ic_some_icon_1_64,
"myapp://example1",
),
...
)
for ((text, icon, uriString) in appButtons) {
buttons.add(
AppButton(
text,
icon
) {
...
}
)
}
But now I get the following:
Destructuring declaration initializer of type Set<{Comparable<*> & java.io.Serializable}> must have a 'component1()' function
Destructuring declaration initializer of type Set<{Comparable<*> & java.io.Serializable}> must have a 'component2()' function
Destructuring declaration initializer of type Set<{Comparable<*> & java.io.Serializable}> must have a 'component3()' function
How do I make this work? How do I create a basic list of objects and loop over them with the correct types? It feels so simple in Python. I'm clearly missing something.

Answer 1

Rather than using maps, you should create a data class. For example:
data class ButtonModel(
val title: String,
val icon: Int,
val uriString: String,
)
You can then create the array like this:
val appButtons = arrayOf(
ButtonModel(
title = getString(R.string.app_btn_example1),
icon = R.drawable.ic_some_icon_1_64,
uriString = "myapp://example1",
),
...
)
Or without the parameter labels if you prefer:
val appButtons = arrayOf(
ButtonModel(
getString(R.string.app_btn_example1),
R.drawable.ic_some_icon_1_64,
"myapp://example1",
),
...
)
Then, rather than getting them with get or [], you can just use the dot syntax:
buttons.add(
AppButton(
entry.text,
entry.icon,
) {
val intent = Intent(Intent.ACTION_VIEW, Uri.parse(entry.uriString)).apply {
val name = getString(R.string.saved_account_key)
putExtra(name, sharedPref.getString(name, null))
}
startActivity(intent)
}
)