Question

I’m building an events app that is very simple, it has a title and start_date and end_date. I would like to filter my query by mixing some of the values, like: if the start_date has passed but the end_date has not, the event is active and should be displayed. If both dates have passed, it should be omitted, too. I think that scopes is the aswer, but I only was able to filter the records within the view using some methods shown below.

I really would like to filter the query that is passed to the controller (@events). I want to show all events that are active, have a future start_date, or a past start_date but are still in progress (Today’s date is in range between start_date and end_date)

EDITED

I have made some scopes which return each part of the query. Chaining them actually substracts the results instead of merging them. So i have used this code and actually works do I do not know how solid or DRY this is. Looks kind of ugly to me… is this a decent way to merge queries in rails 3?

scope :active, where("active = ?", true)
scope :not_over_or_in_progress, lambda { where("start_date < ? AND end_date > ? OR end_date IS NULL AND start_date > ? OR end_date IS NOT NULL AND start_date > ?", Date.today,  Date.today, Date.today, Date.today) }
scope :valid, not_over_or_in_progress.active.order("start_date DESC")

Answer 1

Try using scopes:

class Event < AR::Base
  scope :active, lambda { |date| where("start_date < ? AND end_date > ?", date) }
  scope :future, lambda { |date| where("end_date < ?", date }
  ...
end

# Console
> @active_events = Event.active(Date.today)
> @future_events = Event.future(Date.today)

See http://guides.rubyonrails.org/active_record_querying.html