Class: Dor::GeoMetadataDS

Inherits:
ActiveFedora::OmDatastream
  • Object
show all
Defined in:
lib/dor/datastreams/geo_metadata_ds.rb

Overview

GeoMetadataDS is a Fedora datastream for geographic metadata. It uses the ISO 19139 metadata standard schema - a metadata standard for Geographic Information The datastream is packaged using RDF to identify the optional ISO 19139 feature catalog

See Also:

Author:

  • Darren Hardy

Constant Summary collapse

NS =

namespaces

{
  :rdf => 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
  :gco => 'http://www.isotc211.org/2005/gco',
  :gmd => 'http://www.isotc211.org/2005/gmd',
  :gfc => 'http://www.isotc211.org/2005/gfc'
}
XMLNS =

hash with all namespaces

Hash[NS.map {|k,v| ["xmlns:#{k}", v]
NS_XSD =

schema locations

NS.keys.collect {|k| "#{NS[k]} #{NS[k]}/#{k}.xsd"}

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.xml_template ⇒ Nokogiri::XML::Document

Returns Contains skeleton geoMetadata XML Add your druid as the suffix to rdf:about attributes. Includes all possible xmlns for gmd and gfc.

Returns:

  • (Nokogiri::XML::Document) —

    Contains skeleton geoMetadata XML Add your druid as the suffix to rdf:about attributes. Includes all possible xmlns for gmd and gfc



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# File 'lib/dor/datastreams/geo_metadata_ds.rb', line 53

def self.xml_template
  Nokogiri::XML::Builder.new do |xml|
    xml['rdf'].RDF XMLNS,
      'xmlns:xsi' => 'http://www.w3.org/2001/XMLSchema-instance',
      "xsi:schemaLocation" => NS_XSD.join(' ') do
      xml['rdf'].Description 'rdf:about' => nil do
        xml['gmd'].MD_Metadata
      end
      xml['rdf'].Description 'rdf:about' => nil do
        xml['gfc'].FC_FeatureCatalogue
      end
    end
  end.doc
end

Instance Method Details

#feature_catalogue ⇒ Nokogiri::XML::Document

Returns with gfc:FC_FeatureCatalogue as root node, or nil if not provided.

Returns:



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# File 'lib/dor/datastreams/geo_metadata_ds.rb', line 41

def feature_catalogue
  root = ng_xml.xpath('/rdf:RDF/rdf:Description/gfc:FC_FeatureCatalogue', XMLNS)
  if root.nil? || root.empty?
    nil # Feature catalog is optional
  else
    Nokogiri::XML(root.first.to_xml)
  end
end

#metadata ⇒ Nokogiri::XML::Document

Returns with gmd:MD_Metadata as root node.

Returns:

Raises:



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# File 'lib/dor/datastreams/geo_metadata_ds.rb', line 30

def metadata
  root = ng_xml.xpath('/rdf:RDF/rdf:Description/gmd:MD_Metadata', XMLNS)
  if root.nil? || root.empty?
    raise Dor::ParameterError, "Invalid geoMetadata -- missing MD_Metadata: #{root}"
  else
    Nokogiri::XML(root.first.to_xml)
  end
end

#to_bbox ⇒ Struct

Returns in minX minY maxX maxY order with .w, .e, .n., .s for west, east, north, south as floats.

Returns:

  • (Struct) —

    in minX minY maxX maxY order with .w, .e, .n., .s for west, east, north, south as floats



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# File 'lib/dor/datastreams/geo_metadata_ds.rb', line 70

def to_bbox
  params = { 'xmlns:gmd' => NS[:gmd], 'xmlns:gco' => NS[:gco] }
  bb = metadata.xpath(
    '//gmd:EX_Extent/gmd:geographicElement' +
    '/gmd:EX_GeographicBoundingBox', params).first
  Struct.new(:w, :e, :n, :s).new(
    bb.xpath('gmd:westBoundLongitude/gco:Decimal', params).text.to_f,
    bb.xpath('gmd:eastBoundLongitude/gco:Decimal', params).text.to_f,
    bb.xpath('gmd:northBoundLatitude/gco:Decimal', params).text.to_f,
    bb.xpath('gmd:southBoundLatitude/gco:Decimal', params).text.to_f
  )
end