Tukukkk

I have an Account, User and Group model. All User and Group records belong to an Account, so it is possible for both users and groups to be related to various accounts.

Basically, I have some really hacky, pieced together SQL queries that lookup all Account records related to a given User or Group record through various
associations.

Even though it's fast and only requires a single query for everything to work, I really hate the way it's written.

I was wondering if there is any way I could do this more programatically with something like arel, or if there was a better approach. I also have some security concerns about the code.

class Account < ActiveRecord::Base



  belongs_to :accountable, touch: true, polymorphic: true



  CLAUSE_FOR_RELATED = '"accounts"."accountable_type" = '%s' AND "accounts"."accountable_id" IN (%s)'.freeze



  def self.related_to_user(user)

    groups = user.groups.select('"groups".id')

    friends = user.following_friendships.select('"friendships".following_id')



    queries = 

    queries.push ['Group', groups.to_sql]

    queries.push ['User', friends.to_sql]

    queries.push ['User', user.id]



    self.related_to(queries)

  end



  def self.related_to_group(group)

    queries = [

      ['User', group.members.select('"users".id').to_sql]

    ]



    self.related_to(queries)

  end



  def self.related_to(queries)

    clauses = queries.map do |clause|

      sprintf(CLAUSE_FOR_RELATED, clause[0], clause[1])

    end



    self.where(clauses.join(" OR "))

  end

end

I would try to use as much as possible what is provided by ActiveRecord. I was thinking to something like:

class Account < ActiveRecord::Base

  belongs_to :accountable, touch: true, polymorphic: true

  CLAUSE_FOR_RELATED = '"accounts"."accountable_type" = '%s' AND "accounts"."accountable_id" IN (%s)'.freeze



  class << self

    def related_to_user(user)

      group_ids = user.groups.pluck('groups.id')

      friend_ids = user.following_friendships.pluck('friendships.following_id') 



      query = [

        compose_clause('Group', group_ids.join(', ')),

        compose_clause('User', [user.id, *friend_ids].join(', '))

      ].join(' or ')



      where(query)

    end



    def related_to_group(group)

      member_ids = group.members.pluck('users.id')

      where(compose_clause('User', member_ids.join(', ')))

    end



    private

    def compose_clause(accountable_type, ids)

      sprintf(CLAUSE_FOR_RELATED, accountable_type, ids)

    end

  end

end

Now in Rails 5 you could even write it like:

class Account < ActiveRecord::Base

  belongs_to :accountable, touch: true, polymorphic: true



  class << self

    def related_to_user(user)

      group_ids = user.groups.pluck('groups.id')

      friend_ids = user.following_friendships.pluck('friendships.following_id') 



      where(accountable_type: 'Group', accountable_id: group_ids).or(

         Account.where(accountable_type: 'User', accountable_id: [user.id, *friend_ids])

      )

    end



    def related_to_group(group)

      member_ids = group.members.pluck('users.id')

      where(accountable_type: 'User', accountable_id: member_ids)

    end

  end

end