in my rails app I'm creating an array like so:
@messages.each do |message|
@list << {
:id => message.id,
:title => message.title,
:time_ago => message.replies.first.created_at
}
end
After making this array I would like to then sort it by time_ago ASC order, is that possible?
@list.sort_by{|e| e[:time_ago]}
it defaults to ASC, however if you wanted DESC you can do:
@list.sort_by{|e| -e[:time_ago]}
Also it seems like you are trying to build the list from @messages. You can simply do:
@list = @messages.map{|m|
{:id => m.id, :title => m.title, :time_ago => m.replies.first.created_at }
}
@list. So @messages.each do |message| @list << { :id => message.id, :title => message.title, :time_ago => message.replies.first.created_at } end @list.sort_by...@list.sort_by{|e| e[:time_ago]}.reverse but that really weird that it doesn't work for you.In rails 4+
@list.sort_by(&:time_ago)
You could do:
@list.sort {|a, b| a[:time_ago] <=> b[:time_ago]}
@list.sort_by { |m| m[:time_ago] }.You can also do @list.sort_by { |message| message.time_ago }
{ |message| message.time_ago } part. It's called sort_by because it sorts by the criteria in the block. Here, we're saying to sort by the .time_ago member of the elements. It always sorts ascending. To sort descending, we can sort ascending by the negative of that value, as described in Mike Lewis' answer. :) If it doesn't work, it's because whatever type time_ago has doesn't define negation. :/Just FYI, I don't see the point in moving the messages into a new list and then sorting them. As long as it is ActiveRecord it should be done directly when querying the database in my opinion.
It looks like you should be able to do it like this:
@messages = Message.includes(:replies).order("replies.created_at ASC")
That should be enough unless I have misunderstood the purpose.
Yes, you can use group_by :
http://api.rubyonrails.org/classes/Enumerable.html#method-i-group_by
