这是我遇到的错误:
背景:
我正在尝试根据操作是否完成来显示按钮。这是我的代码
<% if @courses_user.complete! %>
<%= link_to "Completed", course, class: "block text-lg w-full text-center text-white px-4 py-2 bg-green hover:bg-green-dark border-2 border-green-dark leading-none no-underline" %>
<% else %>
<%= link_to "View Modules", course, class: "block text-lg w-full text-center text-grey-dark hover:text-darker px-4 py-2 border-2 border-grey leading-none no-underline hover:border-2 hover:border-grey-dark" %>
<% end %>
在我的courses_user模型中,我有
class CoursesUser < ApplicationRecord
belongs_to :course
belongs_to :user
has_many :course_modules_users
def completed!
self.update_attributes(complete: true)
end
end
在我的welcomeController中
class WelcomeController < ApplicationController
def show
@courses = Course.all.order(created_at: :asc)
@courses_user = CoursesUser.all
end
end
但是我遇到了NoMethodError,我们将提供任何帮助。
答案 0 :(得分:2)
您已经定义了@courses_user = CoursesUser.all
,因此它不是一个单独的对象,而是一个集合。而且您无法致电 complete!
,错误也是如此。
解决方案:
像这样遍历@courses_user
并在每个实例上调用complete!
<% @courses_user.each do |cu| %>
<% if cu.complete! %>
<%= link_to "Completed", course, class: "block text-lg w-full text-center text-white px-4 py-2 bg-green hover:bg-green-dark border-2 border-green-dark leading-none no-underline" %>
<% else %>
<%= link_to "View Modules", course, class: "block text-lg w-full text-center text-grey-dark hover:text-darker px-4 py-2 border-2 border-grey leading-none no-underline hover:border-2 hover:border-grey-dark" %>
<% end %>
<% end %>
注意:
为避免另一个潜在的错误,应将complete!
模型中的completed!
更改为complete!
,因为没有CoursesUser
方法。
所以最终的代码应该是
<% @courses_user.each do |cu| %>
<% if cu.completed! %>
<%= link_to "Completed", course, class: "block text-lg w-full text-center text-white px-4 py-2 bg-green hover:bg-green-dark border-2 border-green-dark leading-none no-underline" %>
<% else %>
<%= link_to "View Modules", course, class: "block text-lg w-full text-center text-grey-dark hover:text-darker px-4 py-2 border-2 border-grey leading-none no-underline hover:border-2 hover:border-grey-dark" %>
<% end %>
<% end %>