CODEWITHSUNDEEP
ruby-on-railsrubyruby-on-rails-4
user2784630
user2784630

Reputation: 806

How to order by the same attribute for multiple parent associations?

I have the models Mom, Dad and Follow which is a polymorphic association. I'm trying to put the Moms and Dads that the user is following in alphabetical order for there name attribute where their both mixed together. Here's what I want and my code so far.

Example User's Followed Mom And Dad List

Adam # Dad
Ashley # Mom
Brenda # Mom
Brian # Dad

Models

class Mom
  has_many :follows, as: :followable
  # columns: name
end

class Dad
  has_many :follows, as: :followable
  # columns: name
end

class Follow
 belongs_to :user
 belongs_to :followable, polymorphic: true

 belongs_to :dad, -> {where( "follows.followable_type = 'Dad'")}, foreign_key: 'followable_id'
 belongs_to :mom, -> {where( "follows.followable_type = 'Mom'")}, foreign_key: 'followable_id'

 scope :name_order, -> { includes(:dad, :mom).order("dads.name ASC",  "moms.name ASC") }
 # columns: user_id, followable_id, followable_type
end

Controller

def index
  @follows = current_user.follows.name_order.paginate(:page => params[:page])
end

Right now this orders them alphabetically but will put the Dads in front of the list and knock all the Moms to the bottom when I need them to mix. How would I do this?

Upvotes: 0

Views: 81

Answers (1)

BroiSatse
BroiSatse

Reputation: 44715

you can try:

 scope :name_order, -> { 
   select("#{table_name}.*, COALESCE(dads.name, mom.name) AS follow_name").
     includes(:dad, :mom).references(:dad, :mom).order("follow_name") 
 }

Note: not tested.

However it seems that your model design is the biggest issue. Since it seems that each Mam and Dad is a user, why not use STI instead?

Upvotes: 2

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