ActiveRecord associations and scopes oh my

Question

I'm trying to figure out how to pull data from multiple tables and making sense of it.

I have events, occurrences and venues tables.

Here are the models/associations so far:

models/event.rb:

class Event < ActiveRecord::Base
 has_many :occurences, :dependent => :destroy
 belongs_to :price
 belongs_to :venue
 validates_presence_of :venue
end

models/venue.rb:

class Venue < ActiveRecord::Base
 has_many :events, :dependent => :destroy
end

models/occurence.rb:

class Occurence < ActiveRecord::Base
 belongs_to  :event
 scope :today, lambda { where("occurence.datetime_start <= ? AND datetime_end >= ?", Time.now.end_of_day, Time.now) }
 scope :this_week, lambda { where("occurence.datetime_start <= ? AND datetime_end <= ?", Time.now.end_of_day, Time.now.at_end_of_week) }
 scope :next_week, lambda { where("occurence.datetime_start > ? AND datetime_end < ?", Time.now.at_end_of_week, Time.now.at_end_of_week + 1.weeks) }
 scope :this_month, lambda { where("occurence.datetime_start <= ? AND datetime_end >= ?", Time.now.end_of_day, Time.now.at_end_of_month) }
 scope :next_month, lambda { where("occurence.datetime_start >= ? AND datetime_end <= ?", Time.now.at_beginning_of_month + 1.months, Time.now.at_end_of_month + 1.months) }
end

What I'd like to show in my view/events/index.html.erb is a table of all events happening today and I like to do something like:

<% @events.today.each do |event|  %>

and display all the events that match the .today scope.

I tried moving the scope to the event model to no avail. Should I move the scopes to the event model? So far my searches have lead me to "Using scope to return results within multiple DateTime ranges in ActiveRecord" and "Multiple scope in rails 3.0" but I can't really make anything out of it.

Can anyone point me in the right direction? Should I create a new function in my event model?

Answer 1

class Event < ActiveRecord::Base
  has_many :occurences, :dependent => :destroy
  belongs_to :price
  belongs_to :venue
  validates_presence_of :venue

  scope :today, lambda {
    joins(:occurences).where("datetime_start <= ? AND datetime_end >= ?", Time.now.end_of_day, Time.now)
  }
end

Answer 2

If you want your syntax to work like:

@events.today

Then the scope would have to be in the Event model.

If you're OK with:

@event.occurences.today

then you're OK now, i.e.:

@events = Event.all
@events.each do |ev|
   ev.occurences.today.each do |oc|
   end
end