如何使用 rolify 将下拉框中的角色关联到用户答案

【问题标题】：how to associate roles from a dropdown box to a user, using rolify如何使用 rolify 将下拉框中的角色关联到用户
【发布时间】：2015-06-08 00:59:46
【问题描述】：

我一直在努力让 rolify gem 永远工作。我也有 cancancan 和 devise，我基本上有一个注册页面，其中包含电子邮件、密码、password_confirmation 和一个选择角色的下拉框。当我点击注册时，它给了我创建 DDbox 的代码段错误。谁能帮我搞定这个工作？我的ability.rb是这样的

`类能力包括 CanCan::Ability

def 初始化（用户）用户 ||=User.new 如果 user.has_role？：行政可以：管理，：所有 elsif user.has_role? :普通用户可以：阅读，菜单 elsif user.has_role? ：机构可以：阅读，菜单 elsif user.has_role? :franchiseOwner 可以：阅读，菜单
结束

# Define abilities for the passed in user here. For example:
#
#   user ||= User.new # guest user (not logged in)
#   if user.admin?
#     can :manage, :all
#   else
#     can :read, :all
#   end
#
# The first argument to `can` is the action you are giving the user
# permission to do.
# If you pass :manage it will apply to every action. Other common actions
# here are :read, :create, :update and :destroy.
#
# The second argument is the resource the user can perform the action on.
# If you pass :all it will apply to every resource. Otherwise pass a Ruby
# class of the resource.
#
# The third argument is an optional hash of conditions to further filter the
# objects.
# For example, here the user can only update published articles.
#
#   can :update, Article, :published => true
#
# See the wiki for details:
# https://github.com/CanCanCommunity/cancancan/wiki/Defining-Abilities
end
 end `

这是我的视图/devise/registation/new.html.erb 中的下拉框代码 sn-p..
<%= user_form.select :role, options_from_collection_for_select(Role.all,"Institution","Regular User", "Franchise Owner")%>

这是我的 User.rb 模型

`class User < ActiveRecord::Base
 rolify :before_add => :before_add_method

 # Include default devise modules. Others available are:
 # :confirmable, :lockable, :timeoutable and :omniauthable
 devise :database_authenticatable, :registerable,
     :recoverable, :rememberable, :trackable, :validatable

 def before_add_method(role)

 end
 end`

还有我的 users_controller

`class UserController < ApplicationController
 def index
  @users = User.all
 end

 def new
   @user = User.new
 end


 # POST /userss
 # POST /users.json
 def create
 @user = User.new(user_params)
 @user.add_role params[:user][:role]
 end

 private
 def user_params
params.require(:user).permit(:email, :password, :password_confirmation,    :role)
end
end`

【问题讨论】：

标签： ruby-on-rails ruby devise rolify

【解决方案1】：

User.new 不保存记录，因此不会有 id。

尝试使用 user.save 或使用 User.create 来保存用户，以便在添加角色之前它有一个 id。否则，该角色将没有用于关联的 user_id。

user = User.create(:email => 'foo@bar.com', :password => 'somestring', :password_confirmation => 'somestring')

user.add_role :rolename

【讨论】：