隐藏的属性不填充Rails 3.2表单中的字段

Question

我正在实现一个邀请系统，我希望new user form预先在表单上的电子邮件地址字段中填充用户的电子邮件地址（最终，我将重构此内容，而不是form_field），以便用户不必输入所有信息，只需输入密码即可。

我已经创造了users.rb模型中的getter/setter方法是这样的：

def invitation_token 
    invitation.invitation_token if invitation 
    end 
    def invitation_token=(invitation_token) 
    self.invitation = Invitation.find_by_invitation_token(invitation_token) 
    end 

邀请MODEL

class Invitation < ActiveRecord::Base 

    #--== ASSOCIATIONS 
    belongs_to :sender, :class_name => 'User' 
    has_one :recipient, :class_name => 'User' 
    #--== CALLBACKS 
    before_create :generate_token 
    before_create :recipient_is_not_registered 
    before_create :decrement_sender_count, :if => :sender 
    #--== VALIDATIONS 
    validates_presence_of :recipient_email 
    #validate :recipient_is_not_registered 
    validate :sender_has_invitations, :if => :sender 
    #--== METHODS 
    private 
    def recipient_is_not_registered 
     if User.find_by_email(recipient_email) 
     false 
     else 
     true 
     end 
    end 

    def sender_has_invitations 
     unless sender.invitation_limit > 0 
     redirect_to root_url 
     end 
    end 

    def generate_token #TODO: MOVE to lib/generate_token.rb 
     self.invitation_token = Digest::SHA1.hexdigest([Time.now, rand].join) 
    end 

    def decrement_sender_count 
     sender.decrement! :invitation_limit 
    end 

end 

用户控制器

class UsersController < ApplicationController 
    def new 
    @user = User.new(:invitation_token => params[:invitation_token]) 
    @user.email = @user.invitation.recipient_email if @user.invitation 
    end 

    def create 
    @user = User.new(user_params) 
    if @user.save 
     session[:user_id] = @user.id 
     redirect_to root_url, notice: "Thank you for signing up!" 
    else 
     render "new" 
    end 
    end 

... 

    def user_params 
    params.require(:user).permit(:email, :password, :password_confirmation, :admin) 
    end 
end 

组的意见/用户/ _form.html.erb

<%= form_for @user do |f| %> 

    <%= f.hidden_field :invitation_token %> 

    <div class="field"> 
    <%= f.label :email %><br /> 
    <%= f.text_field :email %> 
    </div> 
    <div class="field"> 
    <%= f.label :password %><br /> 
    <%= f.password_field :password %> 
    </div> 
    <div class="field"> 
    <%= f.label :password_confirmation %><br /> 
    <%= f.password_field :password_confirmation %> 
    </div> 
    <div class="field"> 
    <%= f.check_box :admin %> 
    <%= f.label :admin %> 
    </div> 
    <div class="actions"><%= f.submit %></div> 
<% end %> 

我下面Ryan Bates的RC＃124 - 测试版邀请，并得到了困在这里。他的代码不会产生错误，所以我应该提到这是一个Rails 3.2.18应用程序。

当我重新加载表单时，用户的电子邮件未填充到表单中。相关日志显示：

Started GET "/signup.914823d28d07b747213ec3de47f89ad537169e34" for 127.0.0.1 
at 2016-04-30 20:24:47 -0600 
Processing by UsersController#new as 
    User Load (1.0ms) SELECT "users".* FROM "users" WHERE "users"."auth_token" = 'rOHiKmDcceytxi_t151YIQ' LIMIT 1 
    Invitation Load (0.0ms) SELECT "invitations".* FROM "invitations" WHERE "invitations"."invitation_token" IS NULL LIMIT 1 
    Rendered users/_form.html.erb (5.0ms) 
    Rendered users/new.html.erb within layouts/application (6.0ms) 
Completed 200 OK in 102.0ms (Views: 25.0ms | ActiveRecord: 3.0ms) 

所以看来invitation_token没有被传递，因为日志显示为NULL。

我已经从上到下浏览了RC代码，无法找出它未被传递的原因。

任何帮助，将不胜感激。谢谢。

UPDATE：从视图源的输出是：

<input id="user_invitation_token" name="user[invitation_token]" type="hidden" />，所以它不是被传递沿。

Answer 1

通过将value:键设置的隐藏字段中的值：

<%= f.hidden_field :invitation_token, value: some_value %>