rails 3，如何在一個組中設置user.role＃創建動作

我有一個groups#new視圖。當current_user登錄時，它們被允許創建一個組。rails 3，如何在一個組中設置user.role＃創建動作

我的羣組＃新視圖：當前用戶的隱藏字段工作正常，但我需要將role = groupleader分配給當前用戶。

<div> 
    <%= fields_for :membership do %> 
    <%= hidden_field_tag "user_id", current_user.id %> 
    <%= hidden_field_tag "role", "groupleader" %> 
    <% end %> 
</div> 
<div class="field"> 
    <%= f.label :title %><br /> 
    <%= f.text_field :title %> 
</div> 
<div class="field"> 
    <%= f.label :description %><br /> 
    <%= f.text_area :description %> 
</div> 
<div class="actions"> 
    <%= f.submit %> 
</div> 
<% end %>

然後在我的組＃創建行動：

def create 
    @group = Group.new(params[:group]) 
    @membership = current_user.memberships.build(:group_id => params[:group_id])

這是建設一個成員，但不影響作用。

我的型號如下：

class Group < ActiveRecord::Base 
    has_many :memberships, :dependent => :destroy 
    has_many :users, :through => :memberships 
    accepts_nested_attributes_for :users 

class User < ActiveRecord::Base #Built with Devise Gem 
    has_and_belongs_to_many :roles 
    has_many :memberships, :dependent => :destroy 
    has_many :groups, :through => :memberships 


class Membership < ActiveRecord::Base 
    attr_accessible :user_id, :group_id 
    belongs_to :user 
    belongs_to :group 
end 


class Role < ActiveRecord::Base 
    has_and_belongs_to_many :users 
end

---編輯以下是我與玩....因爲我通過表單發送的角色參數，

@membership = current_user.memberships.build(:group_id => params[:group_id], :role => params[:role])

這是通過日誌打算什麼：

Parameters: {"group"=>{"title"=>"Test group w/leader", "description"=>"test"}, "commit"=>"Create Group", "role"=>"groupleader", "authenticity_token"=>"+GCK8bJddObwKdCoiqI5QzlGRyuci8b5JxmgXbOjgsc=", "utf8"=>"✓", "user_id"=>"8"} 
User Load (0.3ms) SELECT "users".* FROM "users" WHERE "users"."id" = 8 LIMIT 1 
WARNING: Can't mass-assign protected attributes: role

很顯然，我有一個大規模分配ISSU即

來源

2011-10-16 TJ Sherrill