Rails 形式：显示一个变量的值但将其保存到另一个变量的字段

Question

我有一个包含用户个人资料数据的编辑表单。 User table 中的两个变量是 email 和 new_email。我希望编辑表单中的字段之一 show 用户的 email 但如果在该字段中输入新值，我希望它不会保存到email而不是new_email。所以我想我需要一个用于 new_email 的表单域，它显示 email 的值。我应该如何调整下面的代码来实现这一点？

我目前认为：

<%= form_for(@user) do |f| %>
<%= render 'shared/error_messages', object: f.object %>

<%= f.label :email %>
<%= f.email_field :new_email, class: 'form-control' %>     #!!Relevant line.

<%= f.label :other_fields_like_this %>
<%= f.text_field :other_fields_like_this, class: 'form-control' %>

<%= f.submit "Save changes", class: "btn btn-primary" %>
<% end %>

控制器：

def update
  @user = User.friendly.find(params[:id])
  if @user.update_attributes(userupdate_params)
    if params[:user][:new_email] != @user.email   # That is, if: a new email address is entered, i.e. a value other then the existing value for email is entered
      #save value to new_email instead of to email. How to do this?
       send_confirmation_email
       flash[:success] = "Your email address has not yet been updated. Please check your email for a confirmation link."
       redirect_to @user
     end
    flash[:success] = "Profile updated"
    redirect_to @user
  else
    render 'edit'
  end
end

def userupdate_params
    params.require(:user).permit(#:email,  #email I think can be removed here, since it's new_email whose value will change.
                                 :new_email,
                                 :other_fields_like_this,
                                 :password, 
                                 :password_confirmation)
end

只是为了提供一些背景信息：在此之后我打算用一封确认电子邮件来扩展它。如果用户单击确认 link，则 new_email 的值将覆盖 email 的值。因此，我希望它最初保存到 new_email，只有在确认后才保存到 email.

Answer 1

您可以使用 before_update 回调并将其值分配给 new_email 字段。

Answer 2

您可以为输入字段提供默认值：

<%= f.email_field :new_email, value: @user.email, class: 'form-control' %>

Rails 形式：显示一个变量的值但将其保存到另一个变量的字段

Rails form: A field showing the value of one variable but saving it to another variable

ruby

forms

controller

ruby-on-rails

ruby-on-rails-4