Patterns for displaying errors to users with LiveView

[chrismccord]

Flash is nice for redirecting away from the LV, but for showing the user feedback as they are interacting with your LV, you can simply lean on the existing features:

def render(assigns) do
  ~L"""
  <%= if @notice do %>
    <h2><%= @notice %>
  <% end %>
  ...
  """
end

def mount(_, socket) do
  {:ok, assign(socket, ..., notice: nil)}
end
...
def handle_event(...) do
  case some_thing(...) do
    ... ->
    {:error, _} -> {:noreply, assign(socket, :notice, "it didn't work")}
  end
end

That’s all there is to it, no extra pattern required