toy/lib/toy_web/live/page_live.ex

defmodule ToyWeb.PageLive do
  use ToyWeb, :live_view
  alias Toy.Features

  @impl true
  def mount(_params, _session, socket) do
    {:ok, assign(socket, repo_started: Toy.Features.repo_started?())}
  end

  @impl true
  def handle_event("start_repo", %{}, socket) do
    with {:ok, _} <- Features.start_repo(), do: {:noreply, socket |> assign(repo_started: true)}
  end
end