Module: Lexoranking::Model

Extended by:
ActiveSupport::Concern
Defined in:
lib/lexoranking/model.rb

Overview

Allows your models to sort elements using lexographical sorting

Options: self.ranking_scope - Determine if the elements should be scoped to a specific association before sorting.

Instance Method Summary collapse

Instance Method Details

#rank_first ⇒ Object

Ranks the record to the first postiion of the list and saves it.



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# File 'lib/lexoranking/model.rb', line 32

def rank_first
  rank_to(0)
end

#rank_last ⇒ Object

Ranks the record to the last position of the list and saves it.



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# File 'lib/lexoranking/model.rb', line 27

def rank_last
  rank_to(:last)
end

#rank_to(position) ⇒ Object

Ranks the record to a specific position in the list and saves it.



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# File 'lib/lexoranking/model.rb', line 37

def rank_to(position)
  model_collection = get_collection
  # This return statement handle the case of when there is only one
  # element in the scoped collection and we call this method. Since
  # there is only one element in the collection and the rank column is
  # present there is no reason to calculate the ranking value again.
  return if model_collection.size == 1 && rank.present?
  position = position == :last ? model_collection.size-1 : position.to_i
  previous, nextt = get_prev_next_elements(position, model_collection)
  ranking = calculate_ranking(previous, nextt)

  send("#{self.class.ranking_column}=", ranking)
  save
end

#save ⇒ Object

Rank the record to the last position of the list before saving it.



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# File 'lib/lexoranking/model.rb', line 21

def save
  rank_to(:last) if rank.nil?
  super
end