Class: Amazon::AWS::MultipleOperation

Inherits:
Operation
  • Object
show all
Defined in:
lib/amazon/aws.rb

Overview

This class can be used to merge operations into a single operation. AWS currently supports combining two operations,

Constant Summary

Constants inherited from Operation

Operation::ALL_PARAMETERS, Operation::OPERATIONS, Operation::OPT_PARAMETERS, Operation::PARAMETERS

Instance Attribute Summary

Attributes inherited from Operation

#kind, #params

Instance Method Summary collapse

Methods inherited from Operation

#batch_parameters

Constructor Details

#initialize(operation1, operation2) ⇒ MultipleOperation

This will allow you to take two Operation objects and combine them to form a single object, which can then be used to perform searches. AWS itself imposes the maximum of two combined operations.

operation1 and operation2 are both objects from a subclass of Operation, such as ItemSearch, ItemLookup, etc.

There are currently a few restrictions in the Ruby/AWS implementation of multiple operations:

  • ResponseGroup objects used when calling AWS::Search::Request#search apply to both operations. You cannot have a separate ResponseGroup set per operation.

  • One or both operations may have multiple results pages available, but only the first page can be returned. If you need the other pages, perform the operations separately, not as part of a MultipleOperation.

Example:

is = ItemSearch.new( 'Books', { 'Title' => 'Ruby' } )
il = ItemLookup.new( 'ASIN', { 'ItemId' => 'B0013DZAYO',

‘MerchantId’ => ‘Amazon’ } )

mo = MultipleOperation.new( is, il )

In the above example, we compose a multiple operation consisting of an ItemSearch and an ItemLookup.



682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
 
# File 'lib/amazon/aws.rb', line 682

def initialize(operation1, operation2)

	# Safeguard against changing original Operation objects in place. This
	# is to protect me, not for user code.
	#
	operation1.freeze
	operation2.freeze

	op_kind = '%s,%s' % [ operation1.kind, operation2.kind ]

	# Duplicate Operation objects and remove their Operation parameter.
	# 
	op1 = operation1.dup
	op1.params = op1.params.dup
	op1.params.delete( 'Operation' )

	op2 = operation2.dup
	op2.params = op2.params.dup
	op2.params.delete( 'Operation' )

	if op1.class == op2.class

	  # If both operations are of the same type, we combine the parameters
	  # of both.
	  #
	  b_params = op1.batch_parameters( op1.params, op2.params )
	else

	  # We have to convert the parameters to batch format.
	  #
	  bp1 = op1.batch_parameters( op1.params, {} )
	  bp2 = op2.batch_parameters( op2.params, {} )
	  b_params = bp1.merge( bp2 )
	end

	params = { 'Operation' => op_kind }.merge( b_params )
	super( params )

end