使用一个名为范围

Question

我“想要使用一个命名空间来设置我的用户载体，但保持收到此错误

未定义的方法'目标”的＃<的ActiveRecord ::关联：0x5ee3e40>

应用/模型/ user.rb：19：在`set_carrier '
应用程序/控制器/ users_controller.rb：49：在`块中创建' 应用程序/控制器/ users_controller.rb：48：在`创建”

<div class= "field"> 
    <%= f.label :carrier %><br> 
    <%= f.collection_select(:carrier_name, Carrier.find(:all) ,:name, :name) %> 
</div> 

user.rb

class User < ActiveRecord::Base 

    acts_as_authentic 
    after_create :set_sub 
    after_create :set_universal 
    after_create :set_carrier 

    def set_sub 
    #self.roles << "subscriber" 
    self.roles_mask = 4 
    end 

    def set_universal 
     self.channels << Channel.find(1) 
    end 

    def set_carrier 
    @carrier = Carrier.with_name(self.carrier_name) 
    self.carrier<< @carrier 
    end 

    ROLES = %w[admin moderator subscriber] 

    #Each user can subscribe to many channels 
    has_and_belongs_to_many :channels 

    #Each user who is a moderator can moderate many channels 
    #has_many :channel_mods 
    has_and_belongs_to_many :modifies , :class_name => "Channel" 

    #Each user can receive many messages 
    has_and_belongs_to_many :messages 

    #Each user belongs to a carrier 
    belongs_to :carrier 

    #Filter users by role(s) 
    named_scope :with_role, lambda { |role| {:conditions => "roles_mask & #{2**ROLES.index(role.to_s)} > 0 "} } 

    def roles 
    ROLES.reject { |r| ((roles_mask || 0) & 2**ROLES.index(r)).zero? } 
    end 

    def roles=(roles) 
    self.roles_mask = (roles & ROLES).map { |r| 2**ROLES.index(r) }.sum 
    end 

    def role_symbols 
    roles.map do |role| 
    role.underscore.to_sym # NOT role.name.underscore.to_sym (role is a string) 
    end 
    end 


end 

carrier.rb

class UsersController < ApplicationController 

    filter_resource_access 

    # GET /users 
    # GET /users.xml 
    def index 
    @users = User.all 

    respond_to do |format| 
     format.html # index.html.erb 
     format.xml { render :xml => @users } 
    end 
    end 

    # GET /users/1 
    # GET /users/1.xml 
    def show 
    #@user = User.find(params[:id]) 

    respond_to do |format| 
     format.html # show.html.erb 
     format.xml { render :xml => @user } 
    end 
    end 

    # GET /users/new 
    # GET /users/new.xml 
    def new 
    #@user = User.new 
    @carriers = Carrier.find(:all) 

    respond_to do |format| 
     format.html # new.html.erb 
     format.xml { render :xml => @user } 
    end 
    end 

    # GET /users/1/edit 
    def edit 
    #@user = User.find(params[:id]) 
    end 

    def create 
    #@user = User.new(params[:user]) 
    #@user.channels << Channel.find(1) 

    respond_to do |format| 
     if @user.save 
     format.html { redirect_to(:channels, :notice => 'Registration successfully.') } 
     format.xml { render :xml => @user, :status => :created, :location => @user } 
     else 
     format.html { render :action => "new" } 
     format.xml { render :xml => @user.errors, :status => :unprocessable_entity } 
     end 
    end 
    end 

    def profile 
    @user = User.find(params[:id]) 
    end 



    # PUT /users/1 
    # PUT /users/1.xml 
    def update 
    #@user = current_user 

    respond_to do |format| 
     if @user.update_attributes(params[:user]) 
     format.html { redirect_to(@user, :notice => 'User was successfully updated.') } 
     format.xml { head :ok } 
     else 
     format.html { render :action => "edit" } 
     format.xml { render :xml => @user.errors, :status => :unprocessable_entity } 
     end 
    end 
    end 

    # DELETE /users/1 
    # DELETE /users/1.xml 
    def destroy 
    @user = User.find(params[:id]) 
    @user.destroy 
    respond_to do |format| 
     format.html { redirect_to(users_url) } 
     format.xml { head :ok } 
    end 
    end 

    def delete 
    @user = User.find(params[:user_id]) 
    @user.destroy 
    redirect_to :users 
    end 

end 

Answer 1

你可能在使用的阵列，而不是单数项目

class Carrier < ActiveRecord::Base 
    has_many :users 

    named_scope :with_name, lambda {|name| {:conditions => {:name => name}}} 


end 

用户控制器。 belongs_to关系不是零就是模型。

你可能已经打算做一个直接分配：

def set_carrier 
    self.carrier = Carrier.with_name(self.carrier_name).first 
end 

的<<运算符用于追加项目数组，但carrier不是数组。这可能会在Rails中发生更深层次的东西。

Answer 2

以防万一，这可以帮助任何人：我收到此错误消息也用这样的模式：

def Foo 
    has_many :bars 
    has_many :thingies, through: :bars 
end 

那么我这样做的控制器;

Foo.all.includes(:bars, :thingies) 

它试图通过示波器发生爆炸。解决方法是从包含调用中移除“条” - 它们将自动加载，因为“东西”正在被加载。