Context in fragment for recyclerview - Kotlin - kotlin

Question

I should be able to resolve this as their are so many similar posts on Stack but my brain is just not getting it...
I'm fairly new to android (from flutter) and I want a recyclerview in a fragment... moreover the recycler view doesn't use XML but a custom view class created by some JSON/GSON. None of the online tutorials really cover this and the Stack articles deal with one or another part but not all combined.
I think I have setup my custom views and adapter ok, but no matter what I try I am getting errors from my fragment, mostly related to the context and null parameters.
Here is my fragment class:
class MySquibsFragment : Fragment() {
//var squibGrid: RecyclerView = RecyclerView(requireContext())
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
val v: View = inflater.inflate(R.layout.fragment_my_squibs, container, false)
//squibGrid = v.findViewById<RecyclerView>(R.id.squibgrid)
return v
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val squibList: ArrayList<SquibModel> = ArrayList()
try {
val jsonString = getJSONFromAssets()!!
val squibs = Gson().fromJson(jsonString, Squibs::class.java)
//squibGrid.layoutManager = LinearLayoutManager(activity)
//val itemAdapter = MySquibsAdapter(requireActivity(), squibs.squibs)
//squibGrid.adapter = itemAdapter
} catch (e: JSONException) {
e.printStackTrace()
}
}
The parts that are commented out are the lines that are throwing errors. I've tried moving all of onCreate into onActivityCreated and I've tried using lateinit to get the context, I just can't get my head around it.

Answer 1

Writing val squibGrid = view.findViewById<RecyclerView>(R.id.squibgrid) at the top means that you're trying to find the view when your fragment object is initialized. At that time, the fragment's view is not inflated, so you'll get an exception.
The fragment's view is inflated in onCreateView()
val v: View = inflater.inflate(R.layout.fragment_my_squibs, container, false)
return v
Try moving everything to onViewCreated(). According to the docs for fragment's lifecycle onViewCreated() is called after onCreateView(), i.e after the view is inflated.
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val squibGrid = view.findViewById<RecyclerView>(R.id.squibgrid)
try {
val jsonString = getJSONFromAssets()!!
val squibs = Gson().fromJson(jsonString, Squibs::class.java)
squibGrid.layoutManager = LinearLayoutManager(activity)
val itemAdapter = MySquibsAdapter(requireActivity(), squibs.squibs)
squibGrid.adapter = itemAdapter
} catch (e: JSONException) {
e.printStackTrace()
}
}

Answer 2

Context in fragments will be available after onAttachContext method is called, also your views won't be created before onCreateView, it will crash if you try to access squibGrid in onCreate, You can safely bet on onViewCreated method where context and views are already available to consume
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val squibList: ArrayList<SquibModel> = ArrayList()
try {
val jsonString = getJSONFromAssets()!!
val squibs = Gson().fromJson(jsonString, Squibs::class.java)
//squibGrid.layoutManager = LinearLayoutManager(activity)
//val itemAdapter = MySquibsAdapter(requireActivity(), squibs.squibs)
//squibGrid.adapter = itemAdapter
} catch (e: JSONException) {
e.printStackTrace()
}
}