Module: Mover::ClassMethods

Defined in:
lib/mover.rb

Instance Method Summary collapse

Instance Method Details

#after_move_to(to_class, &block) ⇒ Object 



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# File 'lib/mover.rb', line 14

def after_move_to(to_class, &block)
  @after_move_to ||= []
  @after_move_to << [ to_class, block ]
end

#before_move_to(to_class, &block) ⇒ Object 



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# File 'lib/mover.rb', line 19

def before_move_to(to_class, &block)
  @before_move_to ||= []
  @before_move_to << [ to_class, block ]
end

#move_to(to_class, conditions, instance = nil) ⇒ Object 



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# File 'lib/mover.rb', line 24

def move_to(to_class, conditions, instance=nil)
  from_class = self
  # Conditions
  add_conditions! where = '', conditions
  # Columns
  insert = from_class.column_names & to_class.column_names
  insert -= [ 'moved_at' ]
  insert.collect! { |col| connection.quote_column_name(col) }
  select = insert.clone
  # Magic columns
  if to_class.column_names.include?('moved_at')
    insert << connection.quote_column_name('moved_at')
    select << connection.quote(Time.now.utc)
  end
  # Callbacks
  collector = lambda { |(klass, block)| block if eval(klass.to_s) == to_class }
  before = (@before_move_to || []).collect(&collector).compact
  after = (@after_move_to || []).collect(&collector).compact
  # Instances
  instances =
    if instance
      [ instance ]
    elsif before.empty? && after.empty?
      []
    else
      self.find(:all, :conditions => where[5..-1])
    end
  # Callback executor
  exec_callbacks = lambda do |callbacks|
    callbacks.each do |block|
      instances.each { |instance| instance.instance_eval(&block) }
    end
  end
  # Execute
  transaction do
    exec_callbacks.call before
    connection.execute(<<-SQL)
      INSERT INTO #{to_class.table_name} (#{insert.join(', ')})
      SELECT #{select.join(', ')}
      FROM #{from_class.table_name}
      #{where}
    SQL
    connection.execute("DELETE FROM #{from_class.table_name} #{where}")
    exec_callbacks.call after
  end
end

#reserve_id ⇒ Object 



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# File 'lib/mover.rb', line 71

def reserve_id
  id = nil
  transaction do
    id = connection.insert("INSERT INTO #{self.table_name} () VALUES ()")
    connection.execute("DELETE FROM #{self.table_name} WHERE id = #{id}") if id
  end
  id
end