Organizing by rails datetime in view - ruby-on-rails

Question

I am creating a scheduling app in Rails and I am getting stuck while trying to organize the rooms by date. When I say a room, I essentially just mean a block in the schedule. A typical event might have a lunch (one room), then a networking section (another room). Here is how I am getting the rooms:
#rooms = Room.where(event_id: #current_event.id).order(:start_time)
So that returns the rooms that belong to an event, in order of the start time. In my view I loop through and display the rooms for the event, but I want to group them in the view by the date in case there is an event that is on multiple days.
Also :start_time is a datetime type in Ruby. In human speak, what I would do is look at the date portion and if the room date is not the same as the current group, I would print the new date and continue to group the rooms that fall on that day. Here is a trivial example in case I am not being clear:
Event: Staff Retreat
July 14th, 2015
-----------------------
12:30 PM
Team building Lunch Begins
------------------------
6:30 PM
Team building Dinner Begins
------------------------
July 15th, 2015
------------------------
9:30 AM
Team building Breakfast Begins
So having the grouping of rooms in the #rooms variable that is a datetime, what would be the best way to display a table like the above? I would think that in my loop I should check if the date was the same as the previous room, and if not print the date
- #rooms.each do |room|
room.start_time.strftime("%B %d, %Y")
room.start_time.strftime("%I:%M%p")
room.name
I am having trouble with the logistics because with the Model-View-Controller concept, I feel that sorting in the view may have the view do something it shouldn't have to. I am also struggling with how to do that in the view. I would think setting a variable in the controller that would hold the temporary date as I loop through would work, but it seems like that would start to get pretty messy though. What is the best way to group the various dates from the #rooms variable?

Answer 1

Can you try this. this will return you a hash where date is the key and value will contain all the #rooms related to that time.
#rooms = Room.where(event_id: #current_event.id)
#rooms = Hash[#rooms.sort_by{|o| o.start_time.to_date}.group_by {|room| room.start_time.to_date}.map{|l,m| [l, m.sort_by{|k| k.start_time}]}]
now you can traverse the rooms like this in the views. im putting code in erb format.
<% #rooms.each do |k, v| %>
<%= k %>
<% v.each do |room| %>
<%= room.created_at.start_time('%I:%M %p')%>
<%= #room.name or title what so ever. %>
<% end %>
<% end %>