Class: ActiveFedora::RDFDatastream

Inherits:
File
  • Object
show all
Includes:
ActiveFedora::RDF::DatastreamIndexing, ActiveTriples::NestedAttributes, ActiveTriples::Properties, ActiveTriples::Reflection
Defined in:
lib/active_fedora/rdf/rdf_datastream.rb

Direct Known Subclasses

NtriplesRDFDatastream, RDFXMLDatastream

Class Method Summary collapse

Instance Method Summary collapse

Methods included from ActiveFedora::RDF::DatastreamIndexing

#to_solr

Class Method Details

.parent_uri(ds) ⇒ Object

Trim the last segment off the URI to get the parents uri



20
21
22
23
24
25
26
27
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 20

def parent_uri(ds)
  m = /^(.*)\/[^\/]*$/.match(ds.uri)
  if m
    m[1]
  else
    ::RDF::URI.new(nil)
  end
end

.rdf_subject(&block) ⇒ Object 



13
14
15
16
17
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 13

def rdf_subject(&block)
  return @subject_block = block if block_given?

  @subject_block ||= ->(ds) { parent_uri(ds) }
end

.resource_class(klass = nil) ⇒ Class

ActiveTriples::Resource and include ActiveFedora::RDF::Persistence.

Parameters:

  • klass (Class) (defaults to: nil) —

    an object to set as the resource class, Must be a descendant of

Returns:

  • (Class) —

    the object resource class



34
35
36
37
38
39
40
41
42
43
44
45
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 34

def resource_class(klass = nil)
  if klass
    raise ArgumentError, "#{self} already has a resource_class #{@resource_class}, cannot redefine it to #{klass}" if @resource_class && klass != @resource_class
    raise ArgumentError, "#{klass} must be a subclass of ActiveTriples::Resource" unless klass < ActiveTriples::Resource
  end

  @resource_class ||= begin
                        klass = Class.new(klass || ActiveTriples::Resource)
                        klass.send(:include, RDF::Persistence)
                        klass
                      end
end

Instance Method Details

#content ⇒ Object 



69
70
71
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 69

def content
  serialize
end

#content=(new_content) ⇒ Object 



73
74
75
76
77
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 73

def content=(new_content)
  resource.clear!
  resource << deserialize(new_content)
  content
end

#content_changed? ⇒ Boolean

Returns:

  • (Boolean) 


84
85
86
87
88
89
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 84

def content_changed?
  return false unless instance_variable_defined? :@resource
  return true if empty_or_blank_subject? # can't be serialized because a subject hasn't been assigned yet.
  @content = serialize
  super
end

#deserialize(data = nil) ⇒ Object 



151
152
153
154
155
156
157
158
159
160
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 151

def deserialize(data = nil)
  return ::RDF::Graph.new if new_record? && data.nil?
  data ||= remote_content

  # Because datastream_content can return nil, we should check that here.
  return ::RDF::Graph.new if data.nil?

  data.force_encoding('utf-8')
  ::RDF::Graph.new << ::RDF::Reader.for(serialization_format).new(data)
end

#empty_or_blank_subject? ⇒ Boolean

Returns:

  • (Boolean) 


91
92
93
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 91

def empty_or_blank_subject?
  resource.rdf_subject.node? || resource.rdf_subject.value.blank?
end

#freeze ⇒ Object 



95
96
97
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 95

def freeze
  @resource.freeze
end

#metadata? ⇒ Boolean

Returns:

  • (Boolean) 


65
66
67
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 65

def metadata?
  true
end

#parent_uri ⇒ Object 



61
62
63
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 61

def parent_uri
  self.class.parent_uri(self)
end

#refresh_attributes ⇒ Object 



125
126
127
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 125

def refresh_attributes
  @resource = nil
end

#resource ⇒ Object Also known as: graph

The resource is the RdfResource object that stores the graph for the datastream and is the central point for its relationship to other nodes.

set_value, get_value, and property accessors are delegated to this object.



105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 105

def resource
  @resource ||= begin
                  klass = self.class.resource_class
                  klass.properties.merge(self.class.properties).each do |_prop, config|
                    klass.property(config.term,
                                   predicate: config.predicate,
                                   class_name: config.class_name)
                  end
                  klass.accepts_nested_attributes_for(*nested_attributes_options.keys) if nested_attributes_options.present?
                  uri_stub = self.class.rdf_subject.call(self)

                  r = klass.new(uri_stub)
                  r.datastream = self
                  r << deserialize
                  r
                end
end

#serialization_format ⇒ Object 



162
163
164
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 162

def serialization_format
  raise "you must override the `serialization_format' method in a subclass"
end

#serialize ⇒ Object 



146
147
148
149
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 146

def serialize
  resource.set_subject!(parent_uri) if parent_uri && rdf_subject.node?
  resource.dump serialization_format
end

#term_values(*values) ⇒ Object

This method allows for delegation. This patches the fact that there’s no consistent API for allowing delegation - we’re matching the OmDatastream implementation as our “consistency” point. @TODO: We may need to enable deep RDF delegation at one point.



134
135
136
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 134

def term_values(*values)
  send(values.first)
end

#update_indexed_attributes(hash) ⇒ Object 



138
139
140
141
142
143
144
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 138

def update_indexed_attributes(hash)
  hash.each do |fields, value|
    fields.each do |field|
      send("#{field}=", value)
    end
  end
end

#uri=(uri) ⇒ Object 



79
80
81
82
 
# File 'lib/active_fedora/rdf/rdf_datastream.rb', line 79

def uri=(uri)
  super
  resource.set_subject!(parent_uri) if empty_or_blank_subject?
end