[rails] Group By Date (Outlook Style)

[Fletch]

I currently use the following code (have removed formatting) in my view to group results by dates.

<% current_date = nil -%>
<% for item in @items -%>
	
	<% item_published_formatted = item.published.strftime('%d %B %Y') %>


	<% if item_published_formatted != current_date  -%>
		<%= item_published_formatted  %>
	<% end -%>	


	<%= item.title -%>
	 
	<% current_date = item_published_formatted -%>
<% end -%>

This outputs something like:

04 April 2006
Lorium ipsum
An item title
And another

03 April 2006
Item from yesterday
Title

I would like to group the items by date, similarly how Outlook 2003 works. So would look something like:

Today
~items~
Yesterday
~items~
Sunday
~items~
Last Week
~items~
Two Weeks Ago
Three Weeks Ago
Last Month
Two Months Ago

Any ideas on the best way to achieve this?

Thanks,

[vgarcia]

There might be a better way to achieve this, but this is what I got working:

temp_date = nil 
headline = nil
temp_headline = nil
 for item in @items 
 	temp_date = item.published

		if (temp_date > 1.day.ago)
			temp_headline = 'Today'
		elsif (temp_date <= 1.day.ago && temp_date > 2.days.ago)
			temp_headline = 'Yesterday'
		elsif (temp_date <= 2.days.ago && temp_date > 1.week.ago)
			temp_headline = Date::DAYNAMES[item.published.wday]
		elsif (temp_date <= 1.week.ago && temp_date > 2.weeks.ago)
			temp_headline = 'Last Week'
		elsif (temp_date <= 2.weeks.ago && temp_date > 3.weeks.ago)
			temp_headline = '2 Weeks Ago'
		elsif (temp_date <= 3.weeks.ago && temp_date > 4.weeks.ago)
			temp_headline = '3 Weeks Ago'
		elsif (temp_date <= 1.month.ago && temp_date > 2.months.ago)
			temp_headline = 'Last Month'
		else
			temp_headline = 'Older'
		end
	
		if temp_headline != headline
			headline = temp_headline
                         #print out headline here
               end
#print out records/object attributes here
 end

[Fenrir2]

Not tested, but looks a little bit nicer:

headlined = Hash.new([])

for item in list
    headlined[case item.published
              when 0.days.ago..1.day.ago
                "Today"
              when 1.day.ago..2.days.ago
                "Yesterday"
              when 2.days.ago..1.week.ago
                Date.DAYNAMES[item.published.wday]
              when 1.week.ago..2.weeks.ago
                "Last week"
              when 2.weeks.ago..3.weeks.ago
                "2 weeks ago"
              when 3.weeks.ago..4.weeks.ago
                "3 weeks ago"
              when 1.month.ago..2.months.ago
                "Last month"
              else
                "Older"
              end] += [item]
end

headlined SHOULD be a hash containing the headline as the key and an array of objects as value. Note that if you do headlined["some nonexisting key"] you'll get an empty array ([]).

[Fletch]

Thank you both for your help, really good starting point!

I've made a slight change; because "last week" is not strictly 7 days ago. For example today is Wednesday, so I would class the previous Saturday as "last week" even though it is only 4 days ago.

So I've declared

current_wday = Time.now.wday

and changed the 3rd criteria in the if statement to:

temp_date <= 2.days.ago && temp_date > current_wday.days.ago

[vgarcia]

Nice cleanup job Fenrir2

I was trying to get a case statement going initially when I was trying to use Date objects but it wasn't working for me. Your approach looks great though.

[Fenrir2]

Ruby 1.9 has a neat Enumerable#group_by:

headlined = list.group_by{|item|
          case item.published
              when 0.days.ago..1.day.ago
                "Today"
              when 1.day.ago..2.days.ago
                "Yesterday"
              when 2.days.ago..1.week.ago
                Date.DAYNAMES[item.published.wday]
              when 1.week.ago..2.weeks.ago
                "Last week"
              when 2.weeks.ago..3.weeks.ago
                "2 weeks ago"
              when 3.weeks.ago..4.weeks.ago
                "3 weeks ago"
              when 1.month.ago..2.months.ago
                "Last month"
              else
                "Older"
              end
}