Class: Zermelo::Associations::HasMany

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/zermelo/associations/has_many.rb

Instance Method Summary collapse

Constructor Details

#initialize(parent, name) ⇒ HasMany

Returns a new instance of HasMany.



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# File 'lib/zermelo/associations/has_many.rb', line 16

def initialize(parent, name)
  @parent = parent

  @backend = parent.send(:backend)

  @record_ids_key = Zermelo::Records::Key.new(
    :klass  => parent.class.send(:class_key),
    :id     => parent.id,
    :name   => "#{name}_ids",
    :type   => :set,
    :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

#<<(record) ⇒ Object 



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

def <<(record)
  add(record)
  self  # for << 'a' << 'b'
end

#add(*records) ⇒ Object 



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# File 'lib/zermelo/associations/has_many.rb', line 42

def add(*records)
  raise 'No records to add' if records.empty?
  raise 'Invalid record class' if records.any? {|r| !r.is_a?(@associated_class)}
  raise 'Record(s) must have been saved' unless records.all? {|r| r.persisted?} # may need to be moved
  @parent.class.lock(*@lock_klasses) do
    ba = @callbacks[:before_add]
    if ba.nil? || !@parent.respond_to?(ba) || !@parent.send(ba, *records).is_a?(FalseClass)
      unless @inverse.nil?
        records.each do |record|
          @associated_class.send(:load, record.id).send("#{@inverse}=", @parent)
        end
      end

      new_txn = @backend.begin_transaction
      @backend.add(@record_ids_key, records.map(&:id))
      @backend.commit_transaction if new_txn
      aa = @callbacks[:after_add]
      @parent.send(aa, *records) if !aa.nil? && @parent.respond_to?(aa)
    end
  end
end

#delete(*records) ⇒ Object

TODO support dependent delete, for now just deletes the association



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# File 'lib/zermelo/associations/has_many.rb', line 65

def delete(*records)
  raise 'No records to delete' if records.empty?
  raise 'Invalid record class' if records.any? {|r| !r.is_a?(@associated_class)}
  raise 'Record(s) must have been saved' unless records.all? {|r| r.persisted?} # may need to be moved
  @parent.class.lock(*@lock_klasses) do
    br = @callbacks[:before_remove]
    if br.nil? || !@parent.respond_to?(br) || !@parent.send(br, *records).is_a?(FalseClass)
      unless @inverse.nil?
        records.each do |record|
          @associated_class.send(:load, record.id).send("#{@inverse}=", nil)
        end
      end

      new_txn = @backend.begin_transaction
      @backend.delete(@record_ids_key, records.map(&:id))
      @backend.commit_transaction if new_txn
      ar = @callbacks[:after_remove]
      @parent.send(ar, *records) if !ar.nil? && @parent.respond_to?(ar)
    end
  end
end