(Problem solved) Set the value of a livedata variable of type <data class> to a list of strings? - kotlin

Question

How to populate the value of this variable:
private val _urlList = MutableLiveData<List<Url>>()
of type Url:
data class Url(
val imgSrcUrl: String
)
with the incoming list of url strings from a firebase call?
Here is where the magic happens:
private fun getData(){
viewModelScope.launch {
try {
getImagesUrl {
"Here where I need to set the value of the variable to a listOf(it) with it being strings
of urls retrieved from firebase storage"
}
}catch (e: Exception){
"Handling the error"
}
}
}
Edit
The map function #dominicoder provided solved my problem, answer accepted.
Thank you all for your help

Answer 1

Your question is unclear because you're showing a live data of a single Url object but asking to stuff it with a list of strings. So first, your live data object needs to change to a list of Urls:
private val _urlList = MutableLiveData<List<Url>>()
Then, assuming getImagesUrl yields a list of strings, if I understood you correctly, then you would map that to a list of Urls:
getImagesUrl { listOfImageUrlStrings ->
_urlList.value = listOfImageUrlStrings.map { imageUrlString -> Url(imageUrlString) }
}
If that does not answer your question, you really need to review it and clarify.

Answer 2

You can set values on the MutableLiveDataObject in two ways (depends on what you're doing).
Setting the value as normal from the UI thread can be done with:
myLiveData.value = myobject
If you're setting it from a background thread like you might in a coroutine with a suspended function or async task etc then use:
myLiveData.postValue(myObject)
It's not clear from your question whether the LiveData is meant to hold a list as you mention both lists and single values. But your LiveData holds a set the values as a collection like a list, set or map. It's can be treated as a whole object so adding a value later needs to have the whole collection set again like:
myLiveData.value = mutableListOf<Url>()
//Response received and object created
myLiveData.value = myLiveData.value.apply {
add(myObject)
}
Or if the value is mutable updating the existing value (preferred as it's cleaner):
myLiveData.value.add(myObject)
The problem with that approach is you're exposing the map as a mutable/writeable object. Allowing accessors to change the values which you might not want.