class ActiveFedora::Indexing::DescendantFetcher
Finds all descendent URIs of a given repo URI (usually the base URI).
This is a slow and non-performant thing to do, we need to fetch every single object from the repo.
The DescendantFetcher
is also capable of partitioning the URIs into “priority” URIs that will be first in the returned list. These prioritized URIs belong to objects with certain hasModel models. This feature is used in some samvera apps that need to index ‘permissions’ objects before other objects to have the solr indexing work right. And so by default, the prioritized class names are the ones form Hydra::AccessControls, but you can alter the prioritized model name list, or set it to the empty array.
DescendantFetcher.new(ActiveFedora.fedora.base_uri).descendent_and_self_uris #=> array including self uri and descendent uris with "prioritized" (by default) Hydra::AccessControls permissions) objects FIRST.
Change the default prioritized hasModel names:
ActiveFedora::Indexing::DescendantFetcher.default_priority_models = []
Constants
- HAS_MODEL_PREDICATE
Attributes
Public Class Methods
# File lib/active_fedora/indexing/descendant_fetcher.rb, line 30 def initialize(uri, priority_models: self.class.default_priority_models, exclude_self: false) @uri = uri @priority_models = priority_models @exclude_self = exclude_self end
Public Instance Methods
@return [Array<String>] uris starting with priority models
# File lib/active_fedora/indexing/descendant_fetcher.rb, line 38 def descendant_and_self_uris partitioned = descendant_and_self_uris_partitioned partitioned[:priority] + partitioned[:other] end
returns a hash where key :priority is an array of all prioritized type objects, key :other is an array of the rest. @return [Hash<String, Array<String>>] uris sorted into :priority and :other
# File lib/active_fedora/indexing/descendant_fetcher.rb, line 46 def descendant_and_self_uris_partitioned model_partitioned = descendant_and_self_uris_partitioned_by_model { priority: model_partitioned.slice(*priority_models).values.flatten, other: model_partitioned.slice(*(model_partitioned.keys - priority_models)).values.flatten } end
Returns a hash where keys are model names This is useful if you need to action on certain models and want finer grainularity than priority/other @return [Hash<String, Array<String>>] uris sorted by model names
# File lib/active_fedora/indexing/descendant_fetcher.rb, line 55 def descendant_and_self_uris_partitioned_by_model # GET could be slow if it's a big resource, we're using HEAD to avoid this problem, # but this causes more requests to Fedora. return partitioned_uris unless rdf_resource.head.rdf_source? add_self_to_partitioned_uris unless @exclude_self rdf_graph.query({ predicate: ::RDF::Vocab::LDP.contains }).each_object do |uri| descendant_uri = uri.to_s self.class.new( descendant_uri, priority_models: priority_models ).descendant_and_self_uris_partitioned_by_model.tap do |descendant_partitioned| descendant_partitioned.keys.each do |k| partitioned_uris[k] ||= [] partitioned_uris[k].concat descendant_partitioned[k] end end end partitioned_uris end
Protected Instance Methods
# File lib/active_fedora/indexing/descendant_fetcher.rb, line 91 def add_self_to_partitioned_uris rdf_graph.query({ predicate: HAS_MODEL_PREDICATE }).each_object do |model| next unless model.literal? partitioned_uris[model.to_s] ||= [] partitioned_uris[model.to_s] << rdf_resource.subject end end
# File lib/active_fedora/indexing/descendant_fetcher.rb, line 87 def partitioned_uris @partitioned_uris ||= {} end
# File lib/active_fedora/indexing/descendant_fetcher.rb, line 83 def rdf_graph @rdf_graph ||= rdf_resource.graph end
# File lib/active_fedora/indexing/descendant_fetcher.rb, line 79 def rdf_resource @rdf_resource ||= Ldp::Resource::RdfSource.new(ActiveFedora.fedora.build_ntriples_connection, uri) end