PostsListFragment.kt

// ...

private fun fetchPosts() {
        // Verify if Internet is present
        if (!isNetworkAvailable(requireContext())) {
            hideLoadingAnimation()
            showErrorView(R.string.no_internet)
            return
        }
        mViewModel.getPosts()
        mViewModel.postsResponse.observe(viewLifecycleOwner) { (status, data): Resource<PostsResponse?> ->
            if (status === Status.SUCCESS) {
                // If though API succeeded, but maybe no posts are present for now, then we need to display the
                // error message
                if (data?.posts == null) {
                    showErrorView(R.string.no_data_found)
                    return@observe
                }

                // Posts list fetched from the API
                val responsePosts = data.posts

                // Populating the generic list of #PostAdapterModel so as to handle the header views as well
                val formattedPosts: MutableList<PostAdapterModel> = ArrayList()
                
                // ...
                
                mapDataOnRecyclerView(formattedPosts)
            } else if (status === Status.ERROR) {
                // Tip: You can reproduce this issue by changing the URL to something wrong so that we're sure that
                // the error occurs
                hideLoadingAnimation()
                showErrorView(R.string.unexpected_error)
            }
        }
    }

private fun mapDataOnRecyclerView(posts: List<PostAdapterModel>) {
        val recyclerView = requireView().findViewById<RecyclerView>(R.id.recycler_view)
        recyclerView.addItemDecoration(VerticalItemDecoration(requireContext(), 1))
        recyclerView.adapter = PostsAdapter(posts, viewLifecycleOwner, mViewModel, this)
    }

// ...