Class: ActiveFedora::QualifiedDublinCoreDatastream

Inherits:
NokogiriDatastream show all
Defined in:
lib/active_fedora/qualified_dublin_core_datastream.rb

Overview

This class represents a Qualified Dublin Core Datastream. A special case of ActiveFedora::MetdataDatastream The implementation of this class defines the terms from the Qualified Dublin Core specification. This implementation features customized xml generators and deserialization routines to handle the Fedora Dublin Core XML datastreams structure.

Fields can still be overridden if more specificity is desired (see ActiveFedora::Datastream#fields method).

Constant Summary collapse

DCTERMS =

A frozen array of Dublincore Terms.

[
  :contributor, :coverage, :creator,  :description, :identifier, :language, :publisher, :relation,  :source, :title, :abstract, :accessRights, :accrualMethod, :accrualPeriodicity, :accrualPolicy, :alternative, :audience, :available, :bibliographicCitation, :conformsTo, :contributor, :coverage, :created, :creator, :date, :dateAccepted, :dateCopyrighted, :dateSubmitted, :description, :educationLevel, :extent, :hasFormat, :hasPart, :hasVersion, :identifier, :instructionalMethod, :isFormatOf, :isPartOf, :isReferencedBy, :isReplacedBy, :isRequiredBy, :issued, :isVersionOf, :language, :license, :mediator, :medium, :modified, :provenance, :publisher, :references, :relation, :replaces, :requires, :rights, :rightsHolder, :source, :spatial, :subject, :tableOfContents, :temporal,  :valid
]

Instance Attribute Summary collapse

Attributes inherited from NokogiriDatastream

#internal_solr_doc

Attributes included from MetadataDatastreamHelper

#xml_loaded

Attributes inherited from Datastream

#digital_object, #dirty, #last_modified

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from NokogiriDatastream

#content=, #find_by_terms, #from_solr, from_xml, #generate_solr_symbol, #get_values, #get_values_from_solr, #has_solr_name?, #is_hierarchical_term_pointer?, #ng_xml, #ng_xml=, #om_term_values, #om_update_values, #term_values, #to_xml, #update_values

Methods included from MetadataDatastreamHelper

#ensure_xml_loaded, included, #serialize!

Methods inherited from Datastream

#add_ds_location, #add_mime_type, #create, #dirty?, from_xml, #inspect, #new_object?, #profile_from_hash, #save, #serialize!, #size, #solrize_profile, #to_param, #validate_content_present

Constructor Details

#initialize(digital_object, dsid) ⇒ QualifiedDublinCoreDatastream

Constructor. this class will call self.field for each DCTERM. In short, all DCTERMS fields will already exist when this method returns. Each term is marked as a multivalue string.



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# File 'lib/active_fedora/qualified_dublin_core_datastream.rb', line 33

def initialize(digital_object, dsid )
  super(digital_object, dsid)
  DCTERMS.each do |el|
    field el, :string, :multiple=>true
  end
end

Instance Attribute Details

#fields ⇒ Object

TODO this can be removed when Model.find_by_fields_by_solr has been removed.



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# File 'lib/active_fedora/qualified_dublin_core_datastream.rb', line 12

def fields
  @fields
end

Class Method Details

.xml_template ⇒ Object 



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# File 'lib/active_fedora/qualified_dublin_core_datastream.rb', line 94

def self.xml_template
   Nokogiri::XML::Document.parse("<dc xmlns:dcterms='http://purl.org/dc/terms/' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'/>")
end

Instance Method Details

#field(name, tupe = nil, opts = {}) ⇒ Object

This method generates the various accessor and mutator methods on self for the datastream metadata attributes. each field will have the 2 magic methods:

name=(arg) 
name

Calling any of the generated methods marks self as dirty.

‘tupe’ is a datatype, currently :string, :text and :date are supported.

opts is an options hash, which will affect the generation of the xml representation of this datastream.

Currently supported modifiers: For QualifiedDublinCorDatastreams:

:element_attrs =>{:foo=>:bar} -  hash of xml element attributes
:xml_node => :nodename  - The xml node to be used to represent this object (in dcterms namespace)
:encoding=>foo, or encodings_scheme  - causes an xsi:type attribute to be set to 'foo'
:multiple=>true -  mark this field as a multivalue field (on by default)

At some point, these modifiers will be ported up to work for any ActiveFedora::MetadataDatastream.

There is quite a good example of this class in use in spec/examples/oral_history.rb

!! Careful: If you declare two fields that correspond to the same xml node without any qualifiers to differentiate them, you will end up replicating the values in the underlying datastream, resulting in mysterious dubling, quadrupling, etc. whenever you edit the field’s values.



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# File 'lib/active_fedora/qualified_dublin_core_datastream.rb', line 66

def field(name, tupe=nil, opts={})
  fields ||= {}
  @fields[name.to_s.to_sym]={:type=>tupe, :values=>[]}.merge(opts)
  # add term to template
  self.class.class_fields << name.to_s
  # add term to terminology
  unless self.class.terminology.has_term?(name.to_sym)
    term = OM::XML::Term.new(name.to_sym, {:xmlns=>"http://purl.org/dc/terms/", :namespace_prefix => "dcterms"}, self.class.terminology)
    self.class.terminology.add_term(term)
    term.generate_xpath_queries!
  end
  
end

#to_solr(solr_doc = Hash.new) ⇒ Object

:nodoc:



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# File 'lib/active_fedora/qualified_dublin_core_datastream.rb', line 98

def to_solr(solr_doc = Hash.new) # :nodoc:
  @fields.each do |field_key, field_info|
    things = send(field_key)
    if things 
      field_symbol = ActiveFedora::SolrService.solr_name(field_key, field_info[:type])
      things.val.each do |val|    
        ::Solrizer::Extractor.insert_solr_field_value(solr_doc, field_symbol, val )         
      end
    end
  end
  return solr_doc
end

#update_indexed_attributes(params = {}, opts = {}) ⇒ Object 



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# File 'lib/active_fedora/qualified_dublin_core_datastream.rb', line 80

def update_indexed_attributes(params={}, opts={})
  # if the params are just keys, not an array, make then into an array.
  new_params = {}
  params.each do |key, val|
    if key.is_a? Array
      new_params[key] = val
    else
      new_params[[key.to_sym]] = val
    end
  end
  super(new_params, opts)
end