Auto save: update record on every change.

lib/phoenix_auto_save_web/live/post_form_live.ex

@@ -0,0 +1,31 @@
+defmodule PhoenixAutoSaveWeb.PostFormLive do
+  use Phoenix.LiveView
+  use Phoenix.HTML
+
+  alias PhoenixAutoSave.Posts
+
+  def render(assigns) do
+    Phoenix.View.render(PhoenixAutoSaveWeb.PostView, "form.html", assigns)
+  end
+
+  def mount(_params, session, socket) do
+    {
+      :ok,
+      socket
+      |> assign(:changeset, session["changeset"])
+      |> assign(:post, session["post"])
+      |> assign(:action, session["action"])
+    }
+  end
+
+  def handle_event("change", %{"post" => post_params}, socket) do
+    {:ok, post} = Posts.update_post(socket.assigns.post, post_params)
+    {
+      :noreply,
+      socket
+      |> assign(:changeset, Posts.change_post(post))
+      |> assign(:post, post)
+    }
+  end
+
+end

lib/phoenix_auto_save_web/templates/post/edit.html.eex

@@ -1,5 +1,13 @@
 <h1>Edit Post</h1>
 
-<%= render "form.html", Map.put(assigns, :action, Routes.post_path(@conn, :update, @post)) %>
+<%= live_render(
+  @conn,
+  PhoenixAutoSaveWeb.PostFormLive,
+  session: %{
+    "changeset" => @changeset,
+    "action" => Routes.post_path(@conn, :update, @post),
+    "post" => @post
+  }
+) %>
 
 <span><%= link "Back", to: Routes.post_path(@conn, :index) %></span>

lib/phoenix_auto_save_web/templates/post/form.html.eex → lib/phoenix_auto_save_web/templates/post/form.html.leex

@@ -1,4 +1,4 @@
-<%= form_for @changeset, @action, fn f -> %>
+<%= f = form_for @changeset, @action, phx_change: :change %>
   <%= if @changeset.action do %>
     <div class="alert alert-danger">
       <p>Oops, something went wrong! Please check the errors below.</p>
@@ -16,4 +16,4 @@
   <div>
     <%= submit "Save" %>
   </div>
-<% end %>
+</form>