postland/lib/postland_web/live/timeline_live.ex

defmodule PostlandWeb.TimelineLive do
  use PostlandWeb, :live_view

  def render(assigns) do
    ~H"""
    <.post_form post_content={@post} />
    <div id="timeline-posts" phx-update="stream">
      <div :for={{id, post} <- @streams.posts} id={id} class="mt-10">
        <.post_card post={post} />
      </div>
    </div>
    """
  end

  def mount(_params, _session, socket) do
    {:ok, socket |> assign(:post, "") |> stream(:posts, Postland.Timeline.timeline())}
  end

  def handle_event("create_post", %{"post" => post}, socket) do
    {:ok, results} = Postland.Activities.record_markdown_post(post)

    new_posts =
      results
      |> Enum.filter(fn {_key, value} ->
        is_struct(value, Postland.Object)
      end)

    socket =
      socket
      |> assign(:post, "")
      |> then(fn socket ->
        Enum.reduce(new_posts, socket, fn {_id, post}, socket ->
          stream_insert(socket, :posts, post, at: 0)
        end)
      end)

    {:noreply, socket}
  end

  def handle_event("change_post", %{"post" => post}, socket) do
    {:noreply, socket |> assign(:post, post)}
  end
end