Question

目前，我在尝试创建新成员并将其添加到团队时验证没有重复的成员。

members_controller.rb

def create
  @team = current_team
  player = Player.find(params[:player_id])
  @member = @team.add_player(player.id)

  respond_to do |format|
     if @member.save
        format.html { redirect_to(@team, :notice => 'Member was successfully added.') }
        format.js { @current_member = @member }
        format.xml  { render :xml => @member, 
        :status => :created, :location => @member } 
     else
        format.html { redirect_to(@team, :notice => 'Member already exists.') }
        format.xml  { render :xml => @member.errors, 
        :status => :unprocessable_entity }
     end
   end
 end

team.rb

def add_player(player_id)
    current_member = members.build(:player_id => player_id)
    current_member
end

我想在team.rb中的add_player方法中添加一些逻辑，用于检查正在添加的播放器的各种属性。除“会员已存在”外，此操作将需要多条失败消息。我如何在模型层中执行此操作？

Answer 1

您可以在ActiveRecord模型上创建自定义错误。这些自定义错误可以有自己的消息，如果保存不成功，您可以在控制器中查询：

# app/models/team.rb
def add_player(player_id)
    current_member = members.build(:player_id => player_id)
    errors.add(:player_id, 'Custom error message here') if condition
    errors.add(:base, 'Custom error message here') if condition    
    current_member
end

# app/controllers/members_controller.rb
def create
  @team = current_team
  player = Player.find(params[:player_id])
  @member = @team.add_player(player.id)

  respond_to do |format|
     if @member.save
        format.html { redirect_to(@team, :notice => 'Member was successfully added.') }
        format.js { @current_member = @member }
        format.xml  { render :xml => @member, 
        :status => :created, :location => @member } 
     else
        format.html { redirect_to(@team, :notice => @member.errors.full_messages) }
        format.xml  { render :xml => @member.errors, 
        :status => :unprocessable_entity }
     end
   end
 end

有关自定义ActiveRecord验证错误的详细信息，请访问：http://api.rubyonrails.org/v2.3.8/classes/ActiveRecord/Errors.html#M001725

Answer 2

控制器逻辑显示基础工作的所有错误。但是，我无法像Ben建议的那样在add_player方法中添加错误。我改为创建单独的自定义验证：

Team.rb

validate validation_name

def validation_name
  if condition
    errors.add_to_base "Error Message"
  end
end

Rails 3：自定义模型通知

2 个答案: