使用更改集呈现嵌套表单时，字段值会丢失

Question

我的格式如下：

<%= form_for @changeset, account_path(@conn, :create), fn f -> %>

  <div class="row">
    <%= text_input :organization, :name, class: "form-control", required: true %>
    <%= label f, :organization_name %>
    <%= error_tag f, :name %>
  </div>

  <%= inputs_for f, :owner, fn u -> %>

    <div class="row">
      <%= text_input u, :first_name, class: "form-control", required: true %>
      <%= label u, :first_name %>
      <%= error_tag u, :first_name %>
    </div>

    <div class="row">
      <%= text_input u, :last_name, class: "form-control", required: true %>
      <%= label u, :last_name %>
      <%= error_tag u, :last_name %>
    </div>

  <% end %>

<% end %>

我的控制器动作：

case Organizations.create_organization(params["organization"], plan) do
  {:ok, %{user: user}} ->
    ...
  {:error, _resource, changeset, _changes} ->
    conn
    |> put_status(:unprocessable_entity)
    |> put_flash(:error, "Hmm, that didn't work. Please see the errors below.")
    |> render("new.html", changeset: changeset)
end

无效变更集示例：

#Ecto.Changeset<
  action: :insert,
  changes: %{
    name: "test",
    owner: #Ecto.Changeset<
      action: :insert,
      changes: %{
        email: "test@test.com",
        first_name: "asdf",
        id: nil,
        last_name: "asdfasdf",
        password: "testtest",
        password_confirmation: "testtest",
        password_hash: "bla"
      },
      errors: [
        email: {"has already been taken",
         [constraint: :unique, constraint_name: "accounts_users_email_index"]}
      ],
      data: #MyApp.Accounts.User<>,
      valid?: false
    >
  },
  errors: [],
  data: #MyApp.Organizations.Organization<>,
  valid?: false
>

---

问题：当变更集无效时，将保留用户的名字，姓氏和电子邮件字段，但是organization[name]字段将丢失先前输入的值。