Class: RankedModel::Ranker::Mapper

Inherits:
Object
  • Object
show all
Defined in:
lib/ranked-model/ranker.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ranker, instance) ⇒ Mapper

Returns a new instance of Mapper.



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# File 'lib/ranked-model/ranker.rb', line 26

def initialize ranker, instance
  self.ranker   = ranker
  self.instance = instance

  validate_ranker_for_instance!
end

Instance Attribute Details

#instance ⇒ Object

Returns the value of attribute instance.



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# File 'lib/ranked-model/ranker.rb', line 24

def instance
  @instance
end

#ranker ⇒ Object

Returns the value of attribute ranker.



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# File 'lib/ranked-model/ranker.rb', line 24

def ranker
  @ranker
end

Instance Method Details

#current_at_position(_pos) ⇒ Object 



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# File 'lib/ranked-model/ranker.rb', line 90

def current_at_position _pos
  if (ordered_instance = finder.offset(_pos).first)
    RankedModel::Ranker::Mapper.new ranker, ordered_instance
  end
end

#handle_ranking ⇒ Object 



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# File 'lib/ranked-model/ranker.rb', line 52

def handle_ranking
  case ranker.unless
  when Proc
    return if ranker.unless.call(instance)
  when Symbol
    return if instance.send(ranker.unless)
  end

  update_index_from_position
  assure_unique_position
end

#has_rank? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ranked-model/ranker.rb', line 96

def has_rank?
  !rank.nil?
end

#position ⇒ Object 



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# File 'lib/ranked-model/ranker.rb', line 76

def position
  instance.send "#{ranker.name}_position"
end

#rank ⇒ Object 



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# File 'lib/ranked-model/ranker.rb', line 86

def rank
  instance.send "#{ranker.column}"
end

#relative_rank ⇒ Object 



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# File 'lib/ranked-model/ranker.rb', line 80

def relative_rank
  escaped_column = instance_class.connection.quote_column_name ranker.column

  finder.where("#{escaped_column} < #{rank}").count(:all)
end

#reset_ranks! ⇒ Object 



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# File 'lib/ranked-model/ranker.rb', line 72

def reset_ranks!
  finder.update_all(ranker.column => nil)
end

#update_rank!(value) ⇒ Object 



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# File 'lib/ranked-model/ranker.rb', line 64

def update_rank! value
  # Bypass callbacks
  #
  instance_class.
    where(instance_class.primary_key => instance.id).
    update_all(ranker.column => value)
end

#validate_ranker_for_instance! ⇒ Object 



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# File 'lib/ranked-model/ranker.rb', line 33

def validate_ranker_for_instance!
  if ranker.scope && !instance_class.respond_to?(ranker.scope)
    raise RankedModel::InvalidScope, %Q{No scope called "#{ranker.scope}" found in model}
  end

  if ranker.with_same
    if (case ranker.with_same
          when Symbol
            !instance.respond_to?(ranker.with_same)
          when Array
            array_element = ranker.with_same.detect {|attr| !instance.respond_to?(attr) }
          else
            false
        end)
      raise RankedModel::InvalidField, %Q{No field called "#{array_element || ranker.with_same}" found in model}
    end
  end
end