Class: Lbp::Resource

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/lbp/resource.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(resource_url, results) ⇒ Resource

Returns a new instance of Resource.



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# File 'lib/lbp/resource.rb', line 50

def initialize(resource_url, results)
  # if there are problems with results being empty
  # and, for example, dup or filter being called on a null class
  # consider changing the following line to @results = results || <an empty object for whatever results normally is>
  @results = results || RDF::Query::Solutions.new()
  @identifier = ResourceIdentifier.new(resource_url)
end

Instance Attribute Details

#identifier ⇒ Object (readonly)

end class level methods



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# File 'lib/lbp/resource.rb', line 46

def identifier
  @identifier
end

#results ⇒ Object (readonly)

end class level methods



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# File 'lib/lbp/resource.rb', line 46

def results
  @results
end

Class Method Details

.create(resource_url, results) ⇒ Object 



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# File 'lib/lbp/resource.rb', line 29

def create(resource_url, results)
  type = results.dup.filter(:p => RDF::URI("http://www.w3.org/1999/02/22-rdf-syntax-ns#type")).first[:o].to_s.split("/").last
  klass = if type == "workGroup"
      Lbp.const_get("WorkGroup")
    elsif type == "expressionType"
      Lbp.const_get("ExpressionType")
    else
      Lbp.const_get(type.capitalize)
    end
  klass.new(resource_url, results)
rescue NameError
  Resource.new(resource_url, results)
end

.find(resource_id) ⇒ Object 



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# File 'lib/lbp/resource.rb', line 14

def find(resource_id)
  #adding the to_s method allows a resource to be created
  #by passing in an RDF::URL object as well as the url string.
  if resource_id.to_s.include? "http"
    query = Query.new
    results = query.subject("<" + resource_id.to_s + ">")
    resource_url = resource_id.to_s
    create(resource_url, results)
  else
    query = Query.new
    results = query.subject_with_short_id(resource_id)
    resource_url = "http://scta.info/resource/" + resource_id
    create(resource_url, results)
  end
end

Instance Method Details

#description ⇒ Object 



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# File 'lib/lbp/resource.rb', line 88

def description
  value(RDF::Vocab::DC11.description).to_s
end

#has_parts ⇒ Object 



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# File 'lib/lbp/resource.rb', line 91

def has_parts
  values(RDF::Vocab::DC.hasPart)
end

#is_part_of ⇒ Object 



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# File 'lib/lbp/resource.rb', line 94

def is_part_of
  value(RDF::Vocab::DC.isPartOf)
end

#title ⇒ Object 



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# File 'lib/lbp/resource.rb', line 80

def title
  #careful here; title in db is not actualy a uri, but a litteral
  #to_s method should work, but it might not be correct for this to be initially
  #instantiated into a resource identifer.
  # This is why I'm forcing the to_s method in the return value rather than
  # return the ResourceIdentifer object itself as in the case of type above
  value(RDF::Vocab::DC11.title).to_s
end

#type ⇒ Object

query for properties global to all resources



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# File 'lib/lbp/resource.rb', line 77

def type
  value("http://www.w3.org/1999/02/22-rdf-syntax-ns#type")
end

#value(property) ⇒ Object

should return a single resource identifier; and error if there is more than one property for this value



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# File 'lib/lbp/resource.rb', line 65

def value(property) # should return a single resource identifier; and error if there is more than one property for this value
  value = @results.dup.filter(:p => RDF::URI(property))
  if value.count > 0
    value = value.first[:o]
    ResourceIdentifier.new(value)
  else
    nil
  end

end

#values(property) ⇒ Object

generic query methods for all resources



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# File 'lib/lbp/resource.rb', line 59

def values(property) # should return an array of resource identifiers
  results = self.results.dup.filter(:p => RDF::URI(property))
  array = results.map {|m| ResourceIdentifier.new(m[:o])}
  return array
end