Class: Zermelo::Associations::HasOne

Inherits:
Object
  • Object
show all
Defined in:
lib/zermelo/associations/has_one.rb

Instance Method Summary collapse

Constructor Details

#initialize(parent, name) ⇒ HasOne

Returns a new instance of HasOne.



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# File 'lib/zermelo/associations/has_one.rb', line 5

def initialize(parent, name)
  @parent = parent

  @backend = parent.send(:backend)

  # TODO would be better as a 'has_one' hash, a bit like belongs_to
  @record_id_key = Zermelo::Records::Key.new(
    :klass  => parent.class.send(:class_key),
    :id     => parent.id,
    :name   => "#{name}_id",
    :type   => :string,
    :object => :association
  )

  parent.class.send(:with_association_data, name.to_sym) do |data|
    @associated_class = data.data_klass
    @lock_klasses     = [data.data_klass] + data.related_klasses
    @inverse          = data.inverse
    @callbacks        = data.callbacks
  end
end

Instance Method Details

#value ⇒ Object 



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# File 'lib/zermelo/associations/has_one.rb', line 27

def value
  @parent.class.lock(*@associated_class) do
    if id = @backend.get(@record_id_key)
      @associated_class.send(:load, id)
    else
      nil
    end
  end
end

#value=(record) ⇒ Object 



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# File 'lib/zermelo/associations/has_one.rb', line 37

def value=(record)
  if record.nil?
    @parent.class.lock(*@lock_klasses) do
     id = @backend.get(@record_id_key)
     unless id.nil?
       r = @associated_class.send(:load, id)
       unless r.nil?
         bc = @callbacks[:before_clear]
         if bc.nil? || !@parent.respond_to?(bc) || !@parent.send(bc, r).is_a?(FalseClass)
            delete_without_lock(r)
            ac = @callbacks[:after_clear]
            @parent.send(ac, r) if !ac.nil? && @parent.respond_to?(ac)
          end
        end
      end
    end
  else
    raise 'Invalid record class' unless record.is_a?(@associated_class)
    raise 'Record must have been saved' unless record.persisted?
    @parent.class.lock(*@lock_klasses) do
      bs = @callbacks[:before_set]
      if bs.nil? || !@parent.respond_to?(bs) || !@parent.send(bs, r).is_a?(FalseClass)
        unless @inverse.nil?
          @associated_class.send(:load, record.id).send("#{@inverse}=", @parent)
        end

        new_txn = @backend.begin_transaction
        @backend.set(@record_id_key, record.id)
        @backend.commit_transaction if new_txn
        as = @callbacks[:after_set]
        @parent.send(as, record) if !as.nil? && @parent.respond_to?(as)
      end
    end
  end
end