Class: Triannon::LdpWriter

Inherits:
Object
  • Object
show all
Defined in:
app/services/triannon/ldp_writer.rb

Overview

writes data/objects to the LDP server; also does deletes

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(anno, id = nil) ⇒ LdpWriter

Returns a new instance of LdpWriter.

Parameters:

  • anno (Triannon::Annotation) —

    a Triannon::Annotation object

  • id (String) (defaults to: nil) —

    the unique id for the LDP container for the passed annotation; defaults to nil



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# File 'app/services/triannon/ldp_writer.rb', line 49

def initialize(anno, id=nil)
  @anno = anno
  @id = id
  @base_uri = Triannon.config[:ldp_url]
end

Class Method Details

.create_anno(anno) ⇒ Object

use LDP protocol to create the OpenAnnotation.Annotation in an RDF store

Parameters:



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# File 'app/services/triannon/ldp_writer.rb', line 8

def self.create_anno(anno)
  if anno && anno.graph
    # TODO:  special case if the Annotation object already has an id --
    #  see https://github.com/sul-dlss/triannon/issues/84
    ldp_writer = Triannon::LdpWriter.new anno
    id = ldp_writer.create_base

    bodies_solns = anno.graph.query([nil, RDF::OpenAnnotation.hasBody, nil])
    if bodies_solns.size > 0
      ldp_writer.create_body_container
      ldp_writer.create_body_resources
    end

    targets_solns = anno.graph.query([nil, RDF::OpenAnnotation.hasTarget, nil])
    # NOTE:  Annotation is invalid if there are no target statements
    if targets_solns.size > 0
      ldp_writer.create_target_container
      ldp_writer.create_target_resources
    end

    id
  end
end

.delete_container(id) ⇒ Object Also known as: delete_anno

deletes the indicated container and all its child containers from the LDP store

Parameters:

  • id (String) —

    the unique id for the LDP container for an annotation May be a compound id, such as uuid1/t/uuid2, in which case the LDP container object uuid2 and its children are deleted from the LDP store, but LDP containers uuid1/t and uuid1 are not deleted from the LDP store.



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# File 'app/services/triannon/ldp_writer.rb', line 36

def self.delete_container id
  if id && id.size > 0
    ldpw = Triannon::LdpWriter.new nil
    ldpw.delete_containers id
  end
end

Instance Method Details

#create_base ⇒ String

creates a stored LDP container for this object’s Annotation, without its targets or bodies (as those are put in descendant containers)

SIDE EFFECT:  assigns the uuid of the container created to @id

Returns:

  • (String) —

    the unique id for the LDP container created for this annotation



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# File 'app/services/triannon/ldp_writer.rb', line 58

def create_base
  if @anno.graph.query([nil, RDF::Triannon.externalReference, nil]).count > 0
    raise Triannon::ExternalReferenceError, "Incoming annotations may not have http://triannon.stanford.edu/ns/externalReference as a predicate."
  end

  if @anno.graph.id_as_url && @anno.graph.id_as_url.size > 0
    raise Triannon::ExternalReferenceError, "Incoming new annotations may not have an existing id (yet)."
  end

  # TODO:  special case if the Annotation object already has an id --
  #  see https://github.com/sul-dlss/triannon/issues/84

  # we need to work with a copy of the graph so we don't change @anno.graph
  g = RDF::Graph.new
  @anno.graph.each { |s|
    g << s
  }
  g = Triannon::Graph.new(g)
  g.remove_non_base_statements
  g.make_null_relative_uri_out_of_blank_node

  @id = create_resource g.to_ttl
end

#create_body_container ⇒ Object

creates the LDP container for any and all bodies for this annotation



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# File 'app/services/triannon/ldp_writer.rb', line 83

def create_body_container
  create_direct_container RDF::OpenAnnotation.hasBody
end

#create_body_resources ⇒ Object

create the body resources inside the (already created) body container



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# File 'app/services/triannon/ldp_writer.rb', line 93

def create_body_resources
  create_resources_in_container RDF::OpenAnnotation.hasBody
end

#create_target_container ⇒ Object

creates the LDP container for any and all targets for this annotation



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# File 'app/services/triannon/ldp_writer.rb', line 88

def create_target_container
  create_direct_container RDF::OpenAnnotation.hasTarget
end

#create_target_resources ⇒ Object

create the target resources inside the (already created) target container



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# File 'app/services/triannon/ldp_writer.rb', line 98

def create_target_resources
  create_resources_in_container RDF::OpenAnnotation.hasTarget
end

#delete_containers(ldp_container_uris) ⇒ Object

Returns true if a resource was deleted; false otherwise.

Parameters:

  • ldp_container_uris (Array<String>) —

    an Array of ids for LDP containers. (can also be a String) e.g. [@base_uri/(uuid1)/t/(uuid2), @base_uri/(uuid1)/t/(uuid3)] or [@base_uri/(uuid)] or (uuid)

Returns:

  • true if a resource was deleted; false otherwise



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# File 'app/services/triannon/ldp_writer.rb', line 105

def delete_containers ldp_container_uris
  return false if !ldp_container_uris || ldp_container_uris.empty?
  if ldp_container_uris.kind_of? String
    ldp_container_uris = [ldp_container_uris]
  end
  something_deleted = false
  ldp_container_uris.each { |uri|
    ldp_id = uri.to_s.split(@base_uri + '/').last
    resp = conn.delete { |req| req.url ldp_id }
    if resp.status != 204
      raise Triannon::LDPStorageError.new("Unable to delete LDP container #{ldp_id}", resp.status, resp.body)
    end
    something_deleted = true
  }
  something_deleted
end