点击#new&时如何停止NoMethodError #编辑? [英] How to stop NoMethodError when clicking #new & #edit?

问题描述

我很难弄清楚如何将多个控制器的逻辑合并到边栏中.

例如，我想在侧边栏中有一个使用habitus_controller中的@habits逻辑的部分，以及一个使用goals_controller中的@unaccomplished_goals逻辑的部分.

对于这个问题，我们只关注@unaccomplished_goals.

<% @top_3_goals.each do |goal| %>正确显示在应用程序的侧边栏中，如果我单击链接@top_3_goals = @unaccomplished_goals.top_3 BUT 派生的rel ="nofollow">目标/新或目标/1/编辑我很害怕:undefined method each for nil:NilClass！

以下是视图细分:

我在views/layouts/application.html.erb中使用<%= render 'sidebar/sidebar' %> 抓住views/sidebar/_sidebar.html.erb以便使用<%= render 'goals/upcoming' %>抓住views/goals/_upcoming.html.erb

视图/目标/_upcoming.html.erb

 <table>
  <% @top_3_goals.each do |goal| %>
    <tr>
      <td>
        <strong>
          <%= link_to goal.name, edit_goal_path(goal) %>
        </strong>
      </td>
      <td>
        <%= goal.deadline.strftime("%m-%d-%Y") %>
      </td>
    </tr>
  <% end %>
</table> 

views/sidebar/_sidebar.html.erb

 <div id="sidebarsection" class="panel panel-default">
<div id="sidebarheading" class="panel-heading"><h5><b>Upcoming</b></h5></div>
  <%= render 'goals/upcoming' %>
</div> 

目标控制者

   def index
    if params[:tag]
      @goals = Goal.tagged_with(params[:tag])
    else
      @goals = Goal.all.order("deadline")
      @accomplished_goals = current_user.goals.accomplished
      @unaccomplished_goals = current_user.goals.unaccomplished
      @top_3_goals = @unaccomplished_goals.top_3
    end
  end 

目标模型

 class Goal < ActiveRecord::Base
	belongs_to :user
	acts_as_taggable
	scope :accomplished, -> { where(accomplished: true) }
	scope :unaccomplished, -> { where(accomplished: false) }
	validates :name, presence: true

	scope :top_3, -> do
  order("deadline DESC").
  limit(3)
end
end 

我是否需要在sidebar_controller中放入任何内容?我在那里添加了逻辑，但似乎没有任何区别.我仍然是一个初学者，所以我在这里所说的可能没有任何意义.现在，在sidebar_controller中我什么也没有，因为我从那里看到的唯一视图是_sidebar.html.erb(我不太确定partials如何利用控制器).如果在目标索引中渲染了部分_upcoming.html.erb，它会完美工作(所有链接均正常工作)，但是如果在_sidebar中进行渲染，如何使它工作?

非常感谢您对我的支持=]

解决方案

除非有计划使侧栏具有某种iframe或其他功能(这很奇怪)，否则不应将其作为侧栏控制器. /p>

就像@patrickmcgraw建议的那样，我将在应用程序控制器中创建一个before_action以确保始终设置这些变量.

class ApplicationController < ActionController::Base
  before_action :set_top_3_goals

  def set_top_3_goals
    @top_3_goals = current_user.goals.unaccomplished.top_3
  end
end

I'm having a hard time figuring out how to incorporate multiple controller's logic into a sidebar.

For example, I want to have a section in the sidebar that uses @habits logic from the habits_controller and a section that uses @unaccomplished_goals logic from the goals_controller.

For this question let's just focus on @unaccomplished_goals.

<% @top_3_goals.each do |goal| %> shows correctly in the app's sidebar, which is derived from the goals_controller #index @top_3_goals = @unaccomplished_goals.top_3 BUT if I click on links goals/new or goals/1/edit I get the dreaded: undefined method each for nil:NilClass!

Here's a view breakdown:

I use <%= render 'sidebar/sidebar' %> in views/layouts/application.html.erb to grab views/sidebar/_sidebar.html.erb in order to use <%= render 'goals/upcoming' %> to grab views/goals/_upcoming.html.erb

views/goals/_upcoming.html.erb

<table>
  <% @top_3_goals.each do |goal| %>
    <tr>
      <td>
        <strong>
          <%= link_to goal.name, edit_goal_path(goal) %>
        </strong>
      </td>
      <td>
        <%= goal.deadline.strftime("%m-%d-%Y") %>
      </td>
    </tr>
  <% end %>
</table>

views/sidebar/_sidebar.html.erb

<div id="sidebarsection" class="panel panel-default">
<div id="sidebarheading" class="panel-heading"><h5><b>Upcoming</b></h5></div>
  <%= render 'goals/upcoming' %>
</div>

goals controller

  def index
    if params[:tag]
      @goals = Goal.tagged_with(params[:tag])
    else
      @goals = Goal.all.order("deadline")
      @accomplished_goals = current_user.goals.accomplished
      @unaccomplished_goals = current_user.goals.unaccomplished
      @top_3_goals = @unaccomplished_goals.top_3
    end
  end

goal model

class Goal < ActiveRecord::Base
	belongs_to :user
	acts_as_taggable
	scope :accomplished, -> { where(accomplished: true) }
	scope :unaccomplished, -> { where(accomplished: false) }
	validates :name, presence: true

	scope :top_3, -> do
  order("deadline DESC").
  limit(3)
end
end

Do I need to put anything in the sidebar_controller? I played around with adding logic there but it didn't seem to make any difference. I'm still a beginner so what I'm saying here may make no sense. Right now I have nothing in the sidebar_controller since the only view I have from there is _sidebar.html.erb (I'm not quite sure how partials utilize controllers). The partial _upcoming.html.erb worked perfectly if I rendered it in the goals index (the links all worked), but how can I get it to work if I render it in the _sidebar?

Thanks for putting up with me this far =]

解决方案

There shouldn't be such a thing as a sidebar controller, unless you plan to make the sidebar some sort of iframe or something ( which is strange ).

Like @patrickmcgraw suggested, I would create a before_action in the application controller to make sure that those variables are always set.

class ApplicationController < ActionController::Base
  before_action :set_top_3_goals

  def set_top_3_goals
    @top_3_goals = current_user.goals.unaccomplished.top_3
  end
end

这篇关于点击#new&时如何停止NoMethodError #编辑?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！