Phoenix example form

form.html.eex

<%= form_for @changeset, @action, fn f -> %>
  <div>
    <%= label f, :name %>
    <%= text_input f, :name %>
  </div>

  <div>
    <%= submit "Submit" %>
  </div>
<% end %>

new.html.eex

<%= render "form.html", changeset: @changeset,
                        action: user_path(@conn, :create, @user) %>

user_controller.ex

defmodule HelloApp.User do
  use HelloApp.Web, :controller
  
  def new(conn, _params) do
    changeset = HelloApp.User.changeset(%HelloApp.User{})
    render(conn, "new.html", changeset: changeset)
  end
end

This is a minimal example to show how to create a reusable form template. The create action in the controller has been left out purposefully.