Question

• ruby 1.9.2p290
• rails 3.1.1

I have these models:

class Recipe < ActiveRecord::Base
 belongs_to :festivity 
end

class Festivity < ActiveRecord::Base
 has_many :recipes 
end

I have the following field in the “recipes” table:

festivity_id

And the following datetime fields in the “festivities” table:

starts_at
ends_at

How to display the content based on festivities dates?

I started think in this static way:

class PagesController < ApplicationController
 def home
  @recipes_by_festivities = Recipe.where(:festivity_id => 4).all(:order => 'RAND()', :limit => 8)
 end
end

For example: In Xmas period (about all december month), I want to show a recipe list with the festivity_id = 1. In Thanksgiving period I wanna just a list of recipes with festivity_id = 4.

Am I clear? Let me know if I not.

SOLUTION

@current_festivity = Festivity.find(:last, :conditions => ["? between starts_at AND ends_at", Time.utc(0,Time.now.month,Time.now.day,0,0,0)])

@recipes_by_festivities = Recipe.where(:festivity_id => @current_festivity).all(:order => 'RAND()', :limit => 8)

Answer 1

This assumes starts_at and ends_at are saved with the same year (0), except if the period is in the middle of two years (Christmas time, for example): in that case, the ends_at year must be 1.

Festivity.create(name: 'Christmas time', starts_at: Time.utc(0,12,25,0,0,0), ends_at: Time.utc(1,1,6,23,59,59))
Festivity.create(name: 'Ferragosto', starts_at: Time.utc(0,8,15,0,0,0), ends_at: Time.utc(0,8,15,23,59,59))

Recipe.create(festivity: Festivity.find_by_name('Periodo natalizio'))
Recipe.create(festivity: Festivity.find_by_name('Ferragosto'))

# Searching for festivities today
Recipe.includes(:festivity).where(['? BETWEEN festivities.starts_at AND festivities.ends_at', Time.utc(0,Time.now.month,Time.now.day,12,0,0)]).all
# Searching for festivities on 15 August (in Italy there is a festivity that is called Ferragosto)
Recipe.includes(:festivity).where(['? BETWEEN festivities.starts_at AND festivities.ends_at', Time.utc(0,8,15,12,0,0)]).all
# Searching for festivities on 28 December
Recipe.includes(:festivity).where(['? BETWEEN festivities.starts_at AND festivities.ends_at', Time.utc(0,12,28,12,0,0)]).all

And this is a possible implementation of a function:

def recipes_on(day, month)
  Recipe.includes(:festivity).where(['? BETWEEN festivities.starts_at AND festivities.ends_at', Time.utc(0,month,day,12,0,0)]).all
end