Class: RDF::RDFXML::Reader::EvaluationContext

Inherits:
Object
  • Object
show all
Defined in:
lib/rdf/rdfxml/reader.rb

Overview

The Recursive Baggage

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(base, element, graph, &cb) ⇒ EvaluationContext

Returns a new instance of EvaluationContext.



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# File 'lib/rdf/rdfxml/reader.rb', line 25

def initialize(base, element, graph, &cb)
  # Initialize the evaluation context, [5.1]
  self.base = RDF::URI.intern(base)
  @uri_mappings = {}
  @language = nil
  @graph = graph
  @li_counter = 0

  extract_from_element(element, &cb) if element
end

Instance Attribute Details

#base ⇒ Object

:nodoc:



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# File 'lib/rdf/rdfxml/reader.rb', line 18

def base
  @base
end

#graph ⇒ Object

Returns the value of attribute graph.



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# File 'lib/rdf/rdfxml/reader.rb', line 22

def graph
  @graph
end

#language ⇒ Object

Returns the value of attribute language.



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# File 'lib/rdf/rdfxml/reader.rb', line 21

def language
  @language
end

#li_counter ⇒ Object

Returns the value of attribute li_counter.



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# File 'lib/rdf/rdfxml/reader.rb', line 23

def li_counter
  @li_counter
end

#subject ⇒ Object

Returns the value of attribute subject.



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# File 'lib/rdf/rdfxml/reader.rb', line 19

def subject
  @subject
end

#uri_mappings ⇒ Object

Returns the value of attribute uri_mappings.



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# File 'lib/rdf/rdfxml/reader.rb', line 20

def uri_mappings
  @uri_mappings
end

Instance Method Details

#clone(element, options = {}, &cb) ⇒ Object

Clone existing evaluation context adding information from element



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# File 'lib/rdf/rdfxml/reader.rb', line 37

def clone(element, options = {}, &cb)
  new_ec = EvaluationContext.new(@base, nil, @graph)
  new_ec.uri_mappings = self.uri_mappings.clone
  new_ec.language = self.language

  new_ec.extract_from_element(element, &cb) if element
  
  options.each_pair {|k, v| new_ec.send("#{k}=", v)}
  new_ec
end

#extract_from_ancestors(el, &cb) ⇒ Object

Extract Evaluation Context from an element by looking at ancestors recurively



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# File 'lib/rdf/rdfxml/reader.rb', line 49

def extract_from_ancestors(el, &cb)
  ancestors = el.ancestors
  while ancestors.length > 0
    a = ancestors.pop
    next unless a.element?
    extract_from_element(a, &cb)
  end
  extract_from_element(el, &cb)
end

#extract_from_element(el, &cb) ⇒ Object

Extract Evaluation Context from an element



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# File 'lib/rdf/rdfxml/reader.rb', line 60

def extract_from_element(el, &cb)
  b = el.attribute_with_ns("base", RDF::XML.to_s)
  lang = el.attribute_with_ns("lang", RDF::XML.to_s)
  self.base = self.base.join(b) if b
  self.language = lang if lang
  self.uri_mappings.merge!(extract_mappings(el, &cb))
end

#extract_mappings(element, &cb) ⇒ Object

Extract the XMLNS mappings from an element



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# File 'lib/rdf/rdfxml/reader.rb', line 69

def extract_mappings(element, &cb)
  mappings = {}

  # look for xmlns
  element.namespaces.each do |attr_name,attr_value|
    abbr, prefix = attr_name.to_s.split(":")
    if abbr == "xmlns"
      attr_value = self.base.to_s + attr_value if attr_value.match(/^\#/)
      mappings[prefix] = attr_value
      cb.call(prefix, attr_value) if block_given?
    end
  end
  mappings
end

#inspect ⇒ Object 



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# File 'lib/rdf/rdfxml/reader.rb', line 97

def inspect
  v = %w(base subject language).map {|a| "#{a}='#{self.send(a).nil? ? 'nil' : self.send(a)}'"}
  v << "uri_mappings[#{uri_mappings.keys.length}]"
  v.join(",")
end

#li_next ⇒ Object

Produce the next list entry for this context



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# File 'lib/rdf/rdfxml/reader.rb', line 85

def li_next
  @li_counter += 1
  predicate = RDF["_#{@li_counter}"]
end