如何用嵌套模型显示simple_form错误

Question

我有。

/config/routes.rb:

Testivate::Application.routes.draw do
  resources :areas do
    resources :heuristics    
  end
end

/app/models/heuristic.rb:

class Heuristic < ActiveRecord::Base
  attr_accessible :area_id, :blueprint_url
  belongs_to :area
  validates :blueprint_url, :presence => {:message => "Please type the blueprint's internet address"}
end

/app/models/area.rb:

class Area < ActiveRecord::Base
  has_many :heuristics
end

/app/controllers/heuristics_controller.rb:

class HeuristicsController < ApplicationController
  def edit
    @area = Area.find(params[:area_id])
    @heuristic = Heuristic.find(params[:id])
  end
 def update
  @heuristic = Heuristic.find(params[:id])
  @area = Area.find(params[:area_id])
  respond_to do |format|
    if @heuristic.update_attributes(params[:heuristic])
      format.html { redirect_to areas_path, notice: 'Heuristic was successfully updated.' }
      format.json { head :no_content }
    else
      format.html { redirect_to edit_area_heuristic_path(@area, @heuristic) }
      format.json { render json: @heuristic.errors, status: :unprocessable_entity }
    end
  end
 end
end

/app/views/heuristics/new.html.haml:

%h1 New heuristic
= render 'form'
= link_to 'Back', area_heuristics_path(@area)

/app/views/heuristics/_form.html.haml:

= simple_form_for [@area, @heuristic] do |f|
  = f.error_notification
  = f.input :blueprint_url
  = f.button :submit

正如预期的那样，这个应用程序不会让我用一个空的:blueprint_url保存更新。

但是，错误通知并没有出现，我认为这是因为simple_form不知道是显示@area或@启发式的错误还是其他什么。

我如何让它显示我的错误？

rdoc说，您可以将选项传递给error_notifications，但它没有说明在这种情况下应该传递什么选项。

notification

谢谢,

史蒂文。

Answer 1

显示错误的方式是在更新失败时呈现模板，而不是重定向。当您重定向时，您正在丢失所有的错误状态。

def update
  @heuristic = Heuristic.find(params[:id])
  @area = Area.find(params[:area_id])
  respond_to do |format|
    if @heuristic.update_attributes(params[:heuristic])
      format.html { redirect_to areas_path, notice: 'Heuristic was successfully updated.' }
      format.json { head :no_content }
    else
      format.html { render "edit" } # This is the thing that will get your error state
      format.json { render json: @heuristic.errors, status: :unprocessable_entity }
    end
  end
end