在铁路中按月分隔日期

Question

I understand in rails that you can query data using the controller which is what I have been doing.

However say I have a list of dates and I want to visually display them under each month like so:

August:
14/08/2015
25/08/2015
September:
12/09/2015
19/09/2015
October:
3/10/2015
8/10/2015
November:
25/11/2015
5/11/2015

Now I could query each month through the controller but in my eyes this is very inefficient. As a result could you do something like this in the view?

Answer 1

You can group the results with Ruby's collection group_by method :

@items_by_month = @items.group_by{|x| x.created_at.month}

It will result in a Hash with the following structure:

{
  # January
  1 => [item1, item2, ...],
  # February
  2 => [item3, item4, ...],
  # ... and so on
}

Then you can iterate over that Hash in your view.