Rails - will_paginate 说“变量似乎是空的.您是否忘记为 will_paginate 传递集合对象?" [英] Rails - will_paginate says "variable appears to be empty. Did you forget to pass the collection object for will_paginate?"

问题描述

我有这个查询:

@cars = Car.paginate(page: params[:page], per_page: 5).order(created_at: :desc).group_by { |r| r.created_at.to_date }

并在视图中:

= will_paginate @cars

但我收到此错误(在 site#index 中呈现):

But I am getting this error (rendered in site#index):

The @site variable appears to be empty. Did you forget to pass the collection object for will_paginate?

我也尝试以这种方式更新查询:

I've also tried to update the query this way:

@cars = Car.order(created_at: :desc).paginate(page: params[:page], per_page: 5).group_by { |r| r.created_at.to_date }

但是错误还是一样.

如何解决这个问题?

谢谢

推荐答案

您可以在控制器中执行以下操作:

You can do something like this in your controller:

@car_paginator = Car.paginate(page: params[:page], per_page: 5).order(created_at: :desc)
@cars = @car_paginator.group_by { |r| r.created_at.to_date }

然后在您的视图中更改带有分页的行:

Then change the line with the pagination in your view:

= will_paginate @car_paginator

问题是:当你使用 paginate 方法时，结果不是一个普通的数组或数据库关系，而是一个包含一些额外信息的对象，比如 @size.如果您在其上运行 group_by，您将删除额外的属性并返回一个普通的哈希值.

The problem is: When you use the paginate method the results is not a normal array or database relation but an object that has some extra information like @size. If you run group_by on that you remove that extra attributes and return a plain hash.

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