ActiveFedora::Aggregation

Aggregations for ActiveFedora: manage a group of related objects using predicates from the OAI-ORE data model. Provides the foundation for flexible relationships, including items appearing multiple times in a group, flexible/optional ordering, etc.

Used extensively by Hydra::PCDM.

Example

class GenericFile < ActiveFedora::Base
end

generic_file1 = GenericFile.create(id: 'file1')
generic_file2 = GenericFile.create(id: 'file2')

class Image < ActiveFedora::Base
  aggregates :generic_files
end

image = Image.create(id: 'my_image')
image.generic_files = [generic_file2, generic_file1]
image.save

Now the generic_files method returns an ordered list of GenericFile objects.