swap_view_test.exs

Mix.install([
  {:phoenix_playground, "~> 0.1.0"}
])

defmodule ContainerLive do
  use Phoenix.LiveView

  def mount(_params, _session, socket) do
    {:ok, assign(socket, view: DemoLive)}
  end

  def render(assigns) do
    ~H"""
    <%= live_render(@socket, @view, id: "#{@view}-view") %>
    <button phx-click="swap_view">Swap view</button>
    """
  end

  def handle_event("swap_view", _params, socket) do
    {:noreply, update(socket, :view, &swap_view/1)}
  end

  defp swap_view(DemoLive), do: PlaceholderLive
  defp swap_view(PlaceholderLive), do: DemoLive
end

defmodule PlaceholderLive do
  use Phoenix.LiveView

  def mount(_params, _session, socket) do
    {:ok, assign(socket, count: 0)}
  end

  def render(assigns) do
    ~H"""
    <h1>Live View 2</h1>
    <button phx-click="inc">+</button>
    <button phx-click="dec">-</button>
    <span><%= @count %></span>

    <style type="text/css">
      body { padding: 1em; }
    </style>
    """
  end

  def handle_event("inc", _params, socket) do
    {:noreply, assign(socket, count: socket.assigns.count + 1)}
  end

  def handle_event("dec", _params, socket) do
    {:noreply, assign(socket, count: socket.assigns.count - 1)}
  end
end

defmodule DemoLive do
  use Phoenix.LiveView

  def mount(_params, _session, socket) do
    {:ok, assign(socket, count: 0)}
  end

  def render(assigns) do
    ~H"""
    <h1>Live View 1</h1>
    <span><%= @count %></span>
    <button phx-click="inc">+</button>
    <button phx-click="dec">-</button>

    <style type="text/css">
      body { padding: 1em; }
    </style>
    """
  end

  def handle_event("inc", _params, socket) do
    {:noreply, assign(socket, count: socket.assigns.count + 1)}
  end

  def handle_event("dec", _params, socket) do
    {:noreply, assign(socket, count: socket.assigns.count - 1)}
  end
end

PhoenixPlayground.start(live: ContainerLive)