Question

首先，这是我的模特：

class User < ActiveRecord::Base
        has_one :event
    has_one :user_details, :dependent => :destroy
        accepts_nested_attributes_for :user_details, :event
end

class UserDetails < ActiveRecord::Base
    belongs_to :user

    def full_name
        [self.first_name, self.last_name].compact.join(' ')
    end
end

class Event < ActiveRecord::Base
    belongs_to :user
end

我在其中一个观点中有这一行

<%= collection_select(:event, :user_id, User.all, :id, :email) %>

它工作得很好，并在下拉列表中显示所有用户的电子邮件。但我要显示的是下拉列表中的用户full_name，它是user_details模型的一部分。

我该怎么做？

# basically i need to change :email to something like :user_details.full_name, but i'm not sure how.
<%= collection_select(:event, :user_id, User.all, :id, :email)  %>

修改

我试过了：

# undefined method `full_name' for :user_details:Symbol
<%= collection_select(:event, :user_id, User.all, :id, :user_details.full_name)  %>

# This shows the dropdown with a bunch of UserDetails objects aka #<UserDetails:asfjoisdfa>
<%= collection_select(:event, :user_id, User.all, :id, :user_details)  %>

# undefined method `full_name' for #<User:0x007ff18bf0c470>
<%= collection_select(:event, :user_id, User.all, :id, :full_name)  %>

Answer 1

使用以下

<%= collection_select(:event, :user_id, User.all, :id, :full_name)  %>

但您必须在用户模型上声明full_name方法。

# user.rb
def full_name
  user_details.full_name
end

或者您可以使用委托

delegate :full_name, to: :user_details

Answer 2

尝试：

<%= link_to "#{user.user_details.full_name}", "mailto:#{email}" %>

在你看来，让我知道你是如何继续...

修改在user.rb文件中定义一个返回user_details.full_name的帮助器方法并使用它：

<%= collection_select(:event, :user_id, User.all, :id, :*method_returning_user_details.full_name* %>

Answer 3

尝试：
在你看来这

更新：

 <% @fullname = User_details.fullname %>

并在您的collection_select

中

  <%= collection_select(:event, :user_id, User.all, :id, @fullname) %>

并告诉我进展情况。

Rails如何在collection_select中引用has_one

3 个答案: