Class: JSON::LD::Context

Inherits:
Object
  • Object
show all
Includes:
Utils, RDF::Util::Logger
Defined in:
lib/json/ld/context.rb

Defined Under Namespace

Classes: TermDefinition

Constant Summary collapse

PRELOADED =

Preloaded contexts. To avoid runtime context parsing and downloading, contexts may be pre-loaded by implementations.

Returns:

{}
ID_NULL_OBJECT =

The following constants are used to reduce object allocations in #create_term_definition below

{ '@id' => nil }.freeze
NON_TERMDEF_KEYS = 
Set.new(%w(@base @direction @language @protected @version @vocab)).freeze
JSON_LD_10_EXPECTED_KEYS = 
Set.new(%w(@container @id @language @reverse @type)).freeze
JSON_LD_11_EXPECTED_KEYS = 
Set.new(%w(@context @direction @index @nest @prefix @protected)).freeze
JSON_LD_EXPECTED_KEYS = 
(JSON_LD_10_EXPECTED_KEYS + JSON_LD_11_EXPECTED_KEYS).freeze
JSON_LD_10_TYPE_VALUES = 
Set.new(%w(@id @vocab)).freeze
JSON_LD_11_TYPE_VALUES = 
Set.new(%w(@json @none)).freeze
PREFIX_URI_ENDINGS = 
Set.new(%w(: / ? # [ ] @)).freeze
CONTAINERS_GRAPH =

The following constants are used to reduce object allocations in #compact_iri below

%w(@graph@id @graph@id@set).freeze
CONTAINERS_GRAPH_INDEX = 
%w(@graph@index @graph@index@set).freeze
CONTAINERS_GRAPH_INDEX_INDEX = 
%w(@graph@index @graph@index@set @index @index@set).freeze
CONTAINERS_GRAPH_SET = 
%w(@graph @graph@set @set).freeze
CONTAINERS_ID_TYPE = 
%w(@id @id@set @type @set@type).freeze
CONTAINERS_ID_VOCAB = 
%w(@id @vocab @none).freeze
CONTAINERS_INDEX_SET = 
%w(@index @index@set).freeze
CONTAINERS_LANGUAGE = 
%w(@language @language@set).freeze
CONTAINERS_VALUE = 
%w(@value).freeze
CONTAINERS_VOCAB_ID = 
%w(@vocab @id @none).freeze
RDF_LITERAL_NATIVE_TYPES = 
Set.new([RDF::XSD.boolean, RDF::XSD.integer, RDF::XSD.double]).freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Utils

#add_value, #as_array, #as_resource, #blank_node?, #compare_values, #graph?, #has_property, #has_value, #index?, #list?, #node?, #node_or_ref?, #node_reference?, #simple_graph?, #value?

Constructor Details

#initialize(**options) {|ec| ... } ⇒ Context

Create new evaluation context

Parameters:

  • options (Hash)

Options Hash (**options):

  • :base (String, #to_s) —

    The Base IRI to use when expanding the document. This overrides the value of ‘input` if it is a IRI. If not specified and `input` is not an IRI, the base IRI defaults to the current document IRI if in a browser context, or the empty string if there is no document context.

  • :documentLoader (Proc) —

    The callback of the loader to be used to retrieve remote documents and contexts. If specified, it must be used to retrieve remote documents and contexts; otherwise, if not specified, the processor’s built-in loader must be used. See API.documentLoader for the method signature.

  • :prefixes (Hash{Symbol => String}) —

    See ‘RDF::Reader#initialize`

  • :vocab (String, #to_s) —

    Initial value for @vocab

  • :language (String, #to_s) —

    Initial value for @langauge

Yields:

  • (ec)

Yield Parameters:



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# File 'lib/json/ld/context.rb', line 354

def initialize(**options)
  if options[:base]
    @base = @doc_base = RDF::URI(options[:base]).dup
    @doc_base.canonicalize! if options[:canonicalize]
  end
  self.processingMode = options[:processingMode] if options.has_key?(:processingMode)
  @term_definitions = {}
  @iri_to_term = {
    RDF.to_uri.to_s => "rdf",
    RDF::XSD.to_uri.to_s => "xsd"
  }
  @namer = BlankNodeMapper.new("t")

  @options = options

  # Load any defined prefixes
  (options[:prefixes] || {}).each_pair do |k, v|
    next if k.nil?
    @iri_to_term[v.to_s] = k
    @term_definitions[k.to_s] = TermDefinition.new(k, id: v.to_s, simple: true, prefix: true)
  end

  self.vocab = options[:vocab] if options[:vocab]
  self.default_language = options[:language] if options[:language] =~ /^[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*$/
  @term_definitions = options[:term_definitions] if options[:term_definitions]

  #log_debug("init") {"iri_to_term: #{iri_to_term.inspect}"}

  yield(self) if block_given?
end

Instance Attribute Details

#base ⇒ RDF::URI

The base.

Returns:

  • (RDF::URI) —

    Current base IRI, used for expanding relative IRIs.



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# File 'lib/json/ld/context.rb', line 272

def base
  @base
end

#context_base ⇒ RDF::URI

Returns base IRI of the context, if loaded remotely.

Returns:

  • (RDF::URI) —

    base IRI of the context, if loaded remotely.



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# File 'lib/json/ld/context.rb', line 280

def context_base
  @context_base
end

#default_direction ⇒ "lrt", "rtl"

Default direction

This adds a direction to plain strings that aren’t otherwise coerced

Returns:

  • ("lrt", "rtl") 


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# File 'lib/json/ld/context.rb', line 307

def default_direction
  @default_direction
end

#default_language ⇒ String

Default language

This adds a language to plain strings that aren’t otherwise coerced

Returns:

  • (String) 


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# File 'lib/json/ld/context.rb', line 301

def default_language
  @default_language
end

#doc_base ⇒ RDF::URI (readonly)

The base.

Returns:

  • (RDF::URI) —

    Document base IRI, to initialize ‘base`.



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# File 'lib/json/ld/context.rb', line 277

def doc_base
  @doc_base
end

#iri_to_term ⇒ Hash{RDF::URI => String}

Returns Reverse mappings from IRI to term only for terms, not CURIEs XXX.

Returns:

  • (Hash{RDF::URI => String}) —

    Reverse mappings from IRI to term only for terms, not CURIEs XXX



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# File 'lib/json/ld/context.rb', line 287

def iri_to_term
  @iri_to_term
end

#namer ⇒ BlankNodeNamer

Returns:



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# File 'lib/json/ld/context.rb', line 323

def namer
  @namer
end

#options ⇒ Hash{Symbol => Object}

Returns Global options used in generating IRIs.

Returns:

  • (Hash{Symbol => Object}) —

    Global options used in generating IRIs



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# File 'lib/json/ld/context.rb', line 317

def options
  @options
end

#previous_context ⇒ Context

Previous definition for this context. This is used for rolling back type-scoped contexts.

Returns:



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# File 'lib/json/ld/context.rb', line 291

def previous_context
  @previous_context
end

#property_scoped ⇒ Boolean

Context is property-scoped

Returns:

  • (Boolean) 


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# File 'lib/json/ld/context.rb', line 295

def property_scoped
  @property_scoped
end

#provided_context ⇒ Context

Returns A context provided to us that we can use without re-serializing XXX.

Returns:

  • (Context) —

    A context provided to us that we can use without re-serializing XXX



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# File 'lib/json/ld/context.rb', line 320

def provided_context
  @provided_context
end

#term_definitions ⇒ Hash{String => TermDefinition} (readonly)

Term definitions

Returns:



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# File 'lib/json/ld/context.rb', line 284

def term_definitions
  @term_definitions
end

#vocab ⇒ RDF::URI

Default vocabulary

Sets the default vocabulary used for expanding terms which aren’t otherwise absolute IRIs

Returns:



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# File 'lib/json/ld/context.rb', line 314

def vocab
  @vocab
end

Class Method Details

.add_preloaded(url, context = nil, &block) ⇒ Object

Add preloaded context. In the block form, the context is lazy evaulated on first use.

Parameters:

Yield Returns:



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# File 'lib/json/ld/context.rb', line 30

def add_preloaded(url, context = nil, &block)
  PRELOADED[url.to_s.freeze] = context || block
end

.alias_preloaded(a, url) ⇒ Object

Alias a previousliy loaded context

Parameters:



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# File 'lib/json/ld/context.rb', line 38

def alias_preloaded(a, url)
  PRELOADED[a.to_s.freeze] = PRELOADED[url.to_s.freeze]
end

.parse(local_context, protected: false, override_protected: false, propagate: true, **options) ⇒ Context

Create a new context by parsing a context.

Parameters:

Returns:

Raises:

  • (JsonLdError) —

    on a remote context load error, syntax error, or a reference to a term which is not defined.

See Also:



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# File 'lib/json/ld/context.rb', line 334

def self.parse(local_context, protected: false, override_protected: false, propagate: true, **options)
  self.new(**options).parse(local_context, protected: false, override_protected: override_protected, propagate: propagate)
end

Instance Method Details

#as_array?(term) ⇒ Boolean

Should values be represented using an array?

Parameters:

  • term (Term, #to_s) —

    in unexpanded form

Returns:

  • (Boolean) 


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# File 'lib/json/ld/context.rb', line 1200

def as_array?(term)
  return true if CONTEXT_CONTAINER_ARRAY_TERMS.include?(term)
  term = find_definition(term)
  term && (term.as_set? || term.container_mapping.include?('@list'))
end

#coerce(term) ⇒ RDF::URI, '@id'

Retrieve term coercion

Parameters:

  • term (Term, #to_s) —

    in unexpanded form

Returns:



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# File 'lib/json/ld/context.rb', line 1187

def coerce(term)
  # Map property, if it's not an RDF::Value
  # @type is always is an IRI
  return '@id' if term == RDF.type || term == '@type'
  term = find_definition(term)
  term && term.type_mapping
end

#compact_iri(iri, value: nil, vocab: nil, reverse: false, **options) ⇒ String

Compacts an absolute IRI to the shortest matching term or compact IRI

Parameters:

  • iri (RDF::URI)
  • value (Object) (defaults to: nil) —

    Value, used to select among various maps for the same IRI

  • vocab (Boolean) (defaults to: nil) —

    specifies whether the passed iri should be compacted using the active context’s vocabulary mapping

  • reverse (Boolean) (defaults to: false) —

    specifies whether a reverse property is being compacted

  • options (Hash{Symbol => Object}) —

    ({})

Returns:

  • (String) —

    compacted form of IRI

See Also:



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# File 'lib/json/ld/context.rb', line 1406

def compact_iri(iri, value: nil, vocab: nil, reverse: false, **options)
  return if iri.nil?
  iri = iri.to_s

  if vocab && inverse_context.has_key?(iri)
    default_language = if self.default_direction
      "#{self.default_language}_#{self.default_direction}".downcase
    else
      (self.default_language || "@none").downcase
    end
    containers = []
    tl, tl_value = "@language", "@null"
    containers.concat(CONTAINERS_INDEX_SET) if index?(value) && !graph?(value)

    # If the value is a JSON Object with the key @preserve, use the value of @preserve.
    value = value['@preserve'].first if value.is_a?(Hash) && value.has_key?('@preserve')

    if reverse
      tl, tl_value = "@type", "@reverse"
      containers << '@set'
    elsif list?(value)
      # if value is a list object, then set type/language and type/language value to the most specific values that work for all items in the list as follows:
      containers << "@list" unless index?(value)
      list = value['@list']
      common_type = nil
      common_language = default_language if list.empty?
      list.each do |item|
        item_language, item_type = "@none", "@none"
        if value?(item)
          if item.has_key?('@direction')
            item_language = "#{item['@language']}_#{item['@direction']}".downcase
          elsif item.has_key?('@language')
            item_language = item['@language'].downcase
          elsif item.has_key?('@type')
            item_type = item['@type']
          else
            item_language = "@null"
          end
        else
          item_type = '@id'
        end
        common_language ||= item_language
        if item_language != common_language && value?(item)
          common_language = '@none'
        end
        common_type ||= item_type
        if item_type != common_type
          common_type = '@none'
        end
      end

      common_language ||= '@none'
      common_type ||= '@none'
      if common_type != '@none'
        tl, tl_value = '@type', common_type
      else
        tl_value = common_language
      end
    elsif graph?(value)
      # Prefer @index and @id containers, then @graph, then @index
      containers.concat(CONTAINERS_GRAPH_INDEX_INDEX) if index?(value)
      containers.concat(CONTAINERS_GRAPH) if value.has_key?('@id')

      # Prefer an @graph container next
      containers.concat(CONTAINERS_GRAPH_SET)

      # Lastly, in 1.1, any graph can be indexed on @index or @id, so add if we haven't already
      containers.concat(CONTAINERS_GRAPH_INDEX) unless index?(value)
      containers.concat(CONTAINERS_GRAPH) unless value.has_key?('@id')
      containers.concat(CONTAINERS_INDEX_SET) unless index?(value)
      containers << '@set'

      tl, tl_value = '@type', '@id'
    else
      if value?(value)
        # In 1.1, an language map can be used to index values using @none
        if value.has_key?('@language') && !index?(value)
          tl_value = value['@language'].downcase
          tl_value += "_#{value['@direction']}" if value['@direction']
          containers.concat(CONTAINERS_LANGUAGE)
        elsif value.has_key?('@direction') && !index?(value)
          tl_value = "_#{value['@direction']}"
        elsif value.has_key?('@type')
          tl_value = value['@type']
          tl = '@type'
        end
      else
        # In 1.1, an id or type map can be used to index values using @none
        containers.concat(CONTAINERS_ID_TYPE)
        tl, tl_value = '@type', '@id'
      end
      containers << '@set'
    end

    containers << '@none'

    # In 1.1, an index map can be used to index values using @none, so add as a low priority
    containers.concat(CONTAINERS_INDEX_SET) unless index?(value)
    # Values without type or language can use @language map
    containers.concat(CONTAINERS_LANGUAGE) if value?(value) && value.keys == CONTAINERS_VALUE

    tl_value ||= '@null'
    preferred_values = []
    preferred_values << '@reverse' if tl_value == '@reverse'
    if (tl_value == '@id' || tl_value == '@reverse') && value.is_a?(Hash) && value.has_key?('@id')
      t_iri = compact_iri(value['@id'], vocab: true, document_relative: true)
      if (r_td = term_definitions[t_iri]) && r_td.id == value['@id']
        preferred_values.concat(CONTAINERS_VOCAB_ID)
      else
        preferred_values.concat(CONTAINERS_ID_VOCAB)
      end
    else
      tl = '@any' if list?(value) && value['@list'].empty?
      preferred_values.concat([tl_value, '@none'].compact)
    end
    preferred_values << '@any'

    # if containers included `@language` and preferred_values includes something of the form language-tag_direction, add just the _direction part, to select terms that have that direction.
    if lang_dir = preferred_values.detect {|v| v.include?('_')}
      preferred_values << '_' + lang_dir.split('_').last
    end

    if p_term = select_term(iri, containers, tl, preferred_values)
      return p_term
    end
  end

  # At this point, there is no simple term that iri can be compacted to. If vocab is true and active context has a vocabulary mapping:
  if vocab && self.vocab && iri.start_with?(self.vocab) && iri.length > self.vocab.length
    suffix = iri[self.vocab.length..-1]
    return suffix unless term_definitions.has_key?(suffix)
  end

  # The iri could not be compacted using the active context's vocabulary mapping. Try to create a compact IRI, starting by initializing compact IRI to null. This variable will be used to tore the created compact IRI, if any.
  candidates = []

  term_definitions.each do |term, td|
    next if td.nil? || td.id.nil? || td.id == iri || !iri.start_with?(td.id)

    # Skip term if `@prefix` is not true in term definition
    next unless td.prefix?

    suffix = iri[td.id.length..-1]
    ciri = "#{term}:#{suffix}"
    candidates << ciri unless value && term_definitions.has_key?(ciri)
  end

  return candidates.sort.first if !candidates.empty?

  # If we still don't have any terms and we're using standard_prefixes,
  # try those, and add to mapping
  if @options[:standard_prefixes]
    candidates = RDF::Vocabulary.
      select {|v| iri.start_with?(v.to_uri.to_s) && iri != v.to_uri.to_s}.
      map do |v|
        prefix = v.__name__.to_s.split('::').last.downcase
        set_mapping(prefix, v.to_uri.to_s)
        iri.sub(v.to_uri.to_s, "#{prefix}:").sub(/:$/, '')
      end

    return candidates.sort.first if !candidates.empty?
  end

  # If iri could be confused with a compact IRI using a term in this context, signal an error
  term_definitions.each do |term, td|
    next unless iri.to_s.start_with?("#{term}:") && td.prefix?
    raise JSON::LD::JsonLdError:: IRIConfusedWithPrefix, "Absolute IRI '#{iri}' confused with prefix '#{term}'"
  end

  if !vocab
    # transform iri to a relative IRI using the document's base IRI
    iri = remove_base(iri)
    return iri
  else
    return iri
  end
end

#compact_value(property, value, **options) ⇒ Hash

Compact a value

FIXME: revisit the specification version of this.

Parameters:

  • property (String) —

    Associated property used to find coercion rules

  • value (Hash) —

    Value (literal or IRI), in full object representation, to be compacted

  • options (Hash{Symbol => Object})

Returns:

  • (Hash) —

    Object representation of value

Raises:

See Also:



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# File 'lib/json/ld/context.rb', line 1701

def compact_value(property, value, **options)
  #log_debug("compact_value") {"property: #{property.inspect}, value: #{value.inspect}"}

  indexing = index?(value) && container(property).include?('@index')
  language = language(property)
  direction = direction(property)

  result = case
  when coerce(property) == '@id' && value.has_key?('@id') && (value.keys - %w(@id @index)).empty?
    # Compact an @id coercion
    #log_debug("") {" (@id & coerce)"}
    compact_iri(value['@id'])
  when coerce(property) == '@vocab' && value.has_key?('@id') && (value.keys - %w(@id @index)).empty?
    # Compact an @id coercion
    #log_debug("") {" (@id & coerce & vocab)"}
    compact_iri(value['@id'], vocab: true)
  when value.has_key?('@id')
    #log_debug("") {" (@id)"}
    # return value as is
    value
  when value['@type'] && value['@type'] == coerce(property)
    # Compact common datatype
    #log_debug("") {" (@type & coerce) == #{coerce(property)}"}
    value['@value']
  when coerce(property) == '@none' || value['@type']
    # use original expanded value
    value
  when !value['@value'].is_a?(String)
    #log_debug("") {" (native)"}
    indexing || !index?(value) ? value['@value'] : value
  when value['@language'].to_s.downcase == language.to_s.downcase && value['@direction'] == direction
    # Compact language and direction
    indexing || !index?(value) ? value['@value'] : value
  else
    value
  end

  if result.is_a?(Hash) && result.has_key?('@type') && value['@type'] != '@json'
    # Compact values of @type
    c_type =  if result['@type'].is_a?(Array)
      result['@type'].map {|t| compact_iri(t, vocab: true)}
    else
      compact_iri(result['@type'], vocab: true)
    end
    result = result.merge('@type' => c_type)
  end
  
  # If the result is an object, tranform keys using any term keyword aliases
  if result.is_a?(Hash) && result.keys.any? {|k| self.alias(k) != k}
    #log_debug("") {" (map to key aliases)"}
    new_element = {}
    result.each do |k, v|
      new_element[self.alias(k)] = v
    end
    result = new_element
  end

  #log_debug("") {"=> #{result.inspect}"}
  result
end

#container(term) ⇒ Array<'@index', '@language', '@index', '@set', '@type', '@id', '@graph'>

Retrieve container mapping, add it if ‘value` is provided

Parameters:

  • term (Term, #to_s) —

    in unexpanded form

Returns:

  • (Array<'@index', '@language', '@index', '@set', '@type', '@id', '@graph'>) 


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# File 'lib/json/ld/context.rb', line 1176

def container(term)
  return [term] if term == '@list'
  term = find_definition(term)
  term ? term.container_mapping : Set.new
end

#content(term) ⇒ Hash

Retrieve content of a term

Parameters:

  • term (Term, #to_s) —

    in unexpanded form

Returns:

  • (Hash) 


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# File 'lib/json/ld/context.rb', line 1211

def content(term)
  term = find_definition(term)
  term && term.content
end

#create_term_definition(local_context, term, defined, override_protected: false, protected: false) ⇒ Object

Create Term Definition

Term definitions are created by parsing the information in the given local context for the given term. If the given term is a compact IRI, it may omit an IRI mapping by depending on its prefix having its own term definition. If the prefix is a key in the local context, then its term definition must first be created, through recursion, before continuing. Because a term definition can depend on other term definitions, a mechanism must be used to detect cyclical dependencies. The solution employed here uses a map, defined, that keeps track of whether or not a term has been defined or is currently in the process of being defined. This map is checked before any recursion is attempted.

After all dependencies for a term have been defined, the rest of the information in the local context for the given term is taken into account, creating the appropriate IRI mapping, container mapping, and type mapping or language mapping for the term.

Parameters:

  • local_context (Hash)
  • term (String)
  • defined (Hash)
  • protected (Boolean) (defaults to: false) —

    if true, causes all terms to be marked protected

  • override_protected (Boolean) (defaults to: false) —

    Protected terms may be cleared.

  • propagate (Boolean) —

    Context is propagated across node objects.

Raises:

  • (JsonLdError) —

    Represents a cyclical term dependency

See Also:



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# File 'lib/json/ld/context.rb', line 746

def create_term_definition(local_context, term, defined, override_protected: false, protected: false)
  # Expand a string value, unless it matches a keyword
  #log_debug("create_term_definition") {"term = #{term.inspect}"}

  # If defined contains the key term, then the associated value must be true, indicating that the term definition has already been created, so return. Otherwise, a cyclical term definition has been detected, which is an error.
  case defined[term]
  when TrueClass then return
  when nil
    defined[term] = false
  else
    raise JsonLdError::CyclicIRIMapping, "Cyclical term dependency found: #{term.inspect}"
  end

  # Initialize value to a the value associated with the key term in local context.
  value = local_context.fetch(term, false)
  simple_term = value.is_a?(String) || value.nil?

  # Since keywords cannot be overridden, term must not be a keyword. Otherwise, an invalid value has been detected, which is an error.
  if term == '@type' &&
     value.is_a?(Hash) &&
     processingMode("json-ld-1.1") &&
     (value.keys - %w(@container @protected)).empty? &&
     value.fetch('@container', '@set') == '@set'
    # thes are the only cases were redefining a keyword is allowed
  elsif KEYWORDS.include?(term) # TODO anything that looks like a keyword
    raise JsonLdError::KeywordRedefinition, "term must not be a keyword: #{term.inspect}" if
      @options[:validate]
  elsif term.to_s.match?(/^@[a-zA-Z]+$/) && @options[:validate]
    warn "Terms beginning with '@' are reserved for future use and ignored: #{term}."
    return
  elsif !term_valid?(term) && @options[:validate]
    raise JsonLdError::InvalidTermDefinition, "term is invalid: #{term.inspect}"
  end

  value = {'@id' => value} if simple_term

  # Remove any existing term definition for term in active context.
  previous_definition = term_definitions[term]
  if previous_definition && previous_definition.protected? && !override_protected
    # Check later to detect identical redefinition
  else
    term_definitions.delete(term) if previous_definition
  end

  raise JsonLdError::InvalidTermDefinition, "Term definition for #{term.inspect} is an #{value.class} on term #{term.inspect}" unless value.is_a?(Hash)

  #log_debug("") {"Hash[#{term.inspect}] = #{value.inspect}"}
  definition = TermDefinition.new(term)
  definition.simple = simple_term

  expected_keys = case processingMode
  when "json-ld-1.0" then JSON_LD_10_EXPECTED_KEYS
  else JSON_LD_EXPECTED_KEYS
  end

  # Any of these keys cause us to process as json-ld-1.1, unless otherwise set
  if processingMode.nil? && value.any? { |key, _| !JSON_LD_11_EXPECTED_KEYS.include?(key) }
    processingMode('json-ld-11')
  end

  if value.any? { |key, _| !expected_keys.include?(key) }
    extra_keys = value.keys - expected_keys.to_a
    raise JsonLdError::InvalidTermDefinition, "Term definition for #{term.inspect} has unexpected keys: #{extra_keys.join(', ')}"
  end

  # Potentially note that the term is protected
  definition.protected = value.fetch('@protected', protected)

  if value.has_key?('@type')
    type = value['@type']
    # SPEC FIXME: @type may be nil
    type = case type
    when nil
      type
    when String
      begin
        expand_iri(type, vocab: true, documentRelative: false, local_context: local_context, defined: defined)
      rescue JsonLdError::InvalidIRIMapping
        raise JsonLdError::InvalidTypeMapping, "invalid mapping for '@type': #{type.inspect} on term #{term.inspect}"
      end
    else
      :error
    end
    if JSON_LD_11_TYPE_VALUES.include?(type) && processingMode('json-ld-1.1')
      # This is okay and used in compaction in 1.1
    elsif !JSON_LD_10_TYPE_VALUES.include?(type) && !(type.is_a?(RDF::URI) && type.absolute?)
      raise JsonLdError::InvalidTypeMapping, "unknown mapping for '@type': #{type.inspect} on term #{term.inspect}"
    end
    #log_debug("") {"type_mapping: #{type.inspect}"}
    definition.type_mapping = type
  end

  if value.has_key?('@reverse')
    raise JsonLdError::InvalidReverseProperty, "unexpected key in #{value.inspect} on term #{term.inspect}" if
      value.key?('@id') || value.key?('@nest')
    raise JsonLdError::InvalidIRIMapping, "expected value of @reverse to be a string: #{value['@reverse'].inspect} on term #{term.inspect}" unless
      value['@reverse'].is_a?(String)

    # Otherwise, set the IRI mapping of definition to the result of using the IRI Expansion algorithm, passing active context, the value associated with the @reverse key for value, true for vocab, true for document relative, local context, and defined. If the result is not an absolute IRI, i.e., it contains no colon (:), an invalid IRI mapping error has been detected and processing is aborted.
    definition.id =  expand_iri(value['@reverse'],
                                vocab: true,
                                local_context: local_context,
                                defined: defined)
    raise JsonLdError::InvalidIRIMapping, "non-absolute @reverse IRI: #{definition.id} on term #{term.inspect}" unless
      definition.id.is_a?(RDF::Node) || definition.id.is_a?(RDF::URI) && definition.id.absolute?

    if value['@reverse'].to_s.match?(/^@[a-zA-Z]+$/) && @options[:validate]
      warn "Values beginning with '@' are reserved for future use and ignored: #{value['@reverse']}."
      return
    end

    if term[1..-1].to_s.include?(':') && (term_iri = expand_iri(term)) != definition.id
      raise JsonLdError::InvalidIRIMapping, "term #{term} expands to #{definition.id}, not #{term_iri}"
    end

    warn "[DEPRECATION] Blank Node terms deprecated in JSON-LD 1.1." if @options[:validate] && processingMode('json-ld-1.1') && definition.id.to_s.start_with?("_:")

    # If value contains an @container member, set the container mapping of definition to its value; if its value is neither @set, @index, @type, @id, an absolute IRI nor null, an invalid reverse property error has been detected (reverse properties only support set- and index-containers) and processing is aborted.
    if value.has_key?('@container')
      container = value['@container']
      raise JsonLdError::InvalidReverseProperty,
            "unknown mapping for '@container' to #{container.inspect} on term #{term.inspect}" unless
             container.is_a?(String) && (container == '@set' || container == '@index')
      definition.container_mapping = check_container(container, local_context, defined, term)
    end
    definition.reverse_property = true
  elsif value.has_key?('@id') && value['@id'].nil?
    # Allowed to reserve a null term, which may be protected
  elsif value.has_key?('@id') && value['@id'] != term
    raise JsonLdError::InvalidIRIMapping, "expected value of @id to be a string: #{value['@id'].inspect} on term #{term.inspect}" unless
      value['@id'].is_a?(String)

    if !KEYWORDS.include?(value['@id'].to_s) && value['@id'].to_s.match?(/^@[a-zA-Z]+$/) && @options[:validate]
      warn "Values beginning with '@' are reserved for future use and ignored: #{value['@id']}."
      return
    end

    definition.id = expand_iri(value['@id'],
      vocab: true,
      local_context: local_context,
      defined: defined)
    raise JsonLdError::InvalidKeywordAlias, "expected value of @id to not be @context on term #{term.inspect}" if
      definition.id == '@context'

    if term.match?(/(?::[^:])|\//)
      term_iri = expand_iri(term,
                            vocab: true,
                            local_context: local_context,
                            defined: defined.merge(term => true))
      if term_iri != definition.id
        raise JsonLdError::InvalidIRIMapping, "term #{term} expands to #{definition.id}, not #{term_iri}"
      end
    end

    warn "[DEPRECATION] Blank Node terms deprecated in JSON-LD 1.1." if @options[:validate] && processingMode('json-ld-1.1') && definition.id.to_s.start_with?("_:")

    # If id ends with a gen-delim, it may be used as a prefix for simple terms
    definition.prefix = true if !term.include?(':') &&
      simple_term &&
      (definition.id.to_s.end_with?(':', '/', '?', '#', '[', ']', '@') || definition.id.to_s.start_with?('_:'))
  elsif term[1..-1].include?(':')
    # If term is a compact IRI with a prefix that is a key in local context then a dependency has been found. Use this algorithm recursively passing active context, local context, the prefix as term, and defined.
    prefix, suffix = term.split(':', 2)
    create_term_definition(local_context, prefix, defined, protected: protected) if local_context.has_key?(prefix)

    definition.id = if td = term_definitions[prefix]
      # If term's prefix has a term definition in active context, set the IRI mapping for definition to the result of concatenating the value associated with the prefix's IRI mapping and the term's suffix.
      td.id + suffix
    else
      # Otherwise, term is an absolute IRI. Set the IRI mapping for definition to term
      term
    end
    #log_debug("") {"=> #{definition.id}"}
  elsif term.include?('/')
    # If term is a relative IRI
    definition.id = expand_iri(term, vocab: true)
    raise JsonLdError::InvalidKeywordAlias, "expected term to expand to an absolute IRI #{term.inspect}" unless
      definition.id.absolute?
  elsif KEYWORDS.include?(term)
    # This should only happen for @type when @container is @set
    definition.id = term
  else
    # Otherwise, active context must have a vocabulary mapping, otherwise an invalid value has been detected, which is an error. Set the IRI mapping for definition to the result of concatenating the value associated with the vocabulary mapping and term.
    raise JsonLdError::InvalidIRIMapping, "relative term definition without vocab: #{term} on term #{term.inspect}" unless vocab
    definition.id = vocab + term
    #log_debug("") {"=> #{definition.id}"}
  end

  @iri_to_term[definition.id] = term if simple_term && definition.id

  if value.has_key?('@container')
    #log_debug("") {"container_mapping: #{value['@container'].inspect}"}
    definition.container_mapping = check_container(value['@container'], local_context, defined, term)

    # If @container includes @type
    if definition.container_mapping.include?('@type')
      # If definition does not have @type, set @type to @id
      definition.type_mapping ||= '@id'
      # If definition includes @type with a value other than @id or @vocab, an illegal type mapping error has been detected
      if !CONTEXT_TYPE_ID_VOCAB.include?(definition.type_mapping)
        raise JsonLdError::InvalidTypeMapping, "@container: @type requires @type to be @id or @vocab"
      end
    end
  end

  if value.has_key?('@index')
    # property-based indexing
    raise JsonLdError::InvalidTermDefinition, "@index without @index in @container: #{value['@index']} on term #{term.inspect}" unless definition.container_mapping.include?('@index')
    raise JsonLdError::InvalidTermDefinition, "@index must expand to an IRI: #{value['@index']} on term #{term.inspect}" unless value['@index'].is_a?(String) && !value['@index'].start_with?('@')
    definition.index = value['@index'].to_s
  end

  if value.has_key?('@context')
    begin
      self.parse(value['@context'], override_protected: true)
      # Record null context in array form
      definition.context = value['@context'] ? value['@context'] : [nil]
    rescue JsonLdError => e
      raise JsonLdError::InvalidScopedContext, "Term definition for #{term.inspect} contains illegal value for @context: #{e.message}"
    end
  end

  if value.has_key?('@language')
    language = value['@language']
    language = case value['@language']
    when String
      # Warn on an invalid language tag, unless :validate is true, in which case it's an error
      if value['@language'] !~ /^[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*$/
        warn "@language must be valid BCP47: #{value['@language'].inspect}"
      end
      options[:lowercaseLanguage] ? value['@language'].downcase : value['@language']
    when nil
      nil
    else
      raise JsonLdError::InvalidLanguageMapping, "language must be null or a string, was #{value['@language'].inspect}} on term #{term.inspect}"
    end
    #log_debug("") {"language_mapping: #{language.inspect}"}
    definition.language_mapping = language || false
  end

  if value.has_key?('@direction')
    direction = value['@direction']
    raise JsonLdError::InvalidBaseDirection, "direction must be null, 'ltr', or 'rtl', was #{language.inspect}} on term #{term.inspect}" unless direction.nil? || %w(ltr rtl).include?(direction)
    #log_debug("") {"direction_mapping: #{direction.inspect}"}
    definition.direction_mapping = direction || false
  end

  if value.has_key?('@nest')
    nest = value['@nest']
    raise JsonLdError::InvalidNestValue, "nest must be a string, was #{nest.inspect}} on term #{term.inspect}" unless nest.is_a?(String)
    raise JsonLdError::InvalidNestValue, "nest must not be a keyword other than @nest, was #{nest.inspect}} on term #{term.inspect}" if nest.match?(/^@[a-zA-Z]+$/) && nest != '@nest'
    #log_debug("") {"nest: #{nest.inspect}"}
    definition.nest = nest
  end

  if value.has_key?('@prefix')
    raise JsonLdError::InvalidTermDefinition, "@prefix used on compact or relative IRI term #{term.inspect}" if term.match?(%r{:|/})
    case pfx = value['@prefix']
    when TrueClass, FalseClass
      definition.prefix = pfx
    else
      raise JsonLdError::InvalidPrefixValue, "unknown value for '@prefix': #{pfx.inspect} on term #{term.inspect}"
    end

    raise JsonLdError::InvalidTermDefinition, "keywords may not be used as prefixes" if pfx && KEYWORDS.include?(definition.id.to_s)
  end

  if previous_definition && previous_definition.protected? && definition != previous_definition && !override_protected
    definition = previous_definition
    raise JSON::LD::JsonLdError::ProtectedTermRedefinition, "Attempt to redefine protected term #{term}"
  end

  term_definitions[term] = definition
  defined[term] = true
ensure
  # Re-build after term definitions set
  @inverse_context = nil
end

#direction(term) ⇒ String

Retrieve the text direction associated with a term, or the default direction otherwise

Parameters:

  • term (Term, #to_s) —

    in unexpanded form

Returns:

  • (String) 


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# File 'lib/json/ld/context.rb', line 1251

def direction(term)
  term = find_definition(term)
  dir = term && term.direction_mapping
  dir.nil? ? @default_direction : (dir == false ? nil : dir)
end

#dup ⇒ Object 



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# File 'lib/json/ld/context.rb', line 1802

def dup
  # Also duplicate mappings, coerce and list
  that = self
  ec = super
  ec.instance_eval do
    @term_definitions = that.term_definitions.dup
    @iri_to_term = that.iri_to_term.dup
  end
  ec
end

#empty? ⇒ Boolean

Initial context, without mappings, vocab or default language

Returns:

  • (Boolean) 


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# File 'lib/json/ld/context.rb', line 389

def empty?
  @term_definitions.empty? && self.vocab.nil? && self.default_language.nil?
end

#expand_iri(value, documentRelative: false, vocab: false, local_context: nil, defined: nil, as_string: false, **options) ⇒ RDF::Resource, String

Expand an IRI. Relative IRIs are expanded against any document base.

Parameters:

  • value (String) —

    A keyword, term, prefix:suffix or possibly relative IRI

  • documentRelative (Boolean) (defaults to: false) —

    (false)

  • vocab (Boolean) (defaults to: false) —

    (false)

  • local_context (Hash) (defaults to: nil) —

    Used during Context Processing.

  • defined (Hash) (defaults to: nil) —

    Used during Context Processing.

  • as_string (Boolean) (defaults to: false) —

    (false) transform RDF::Resource values to string

  • options (Hash{Symbol => Object})

Returns:

  • (RDF::Resource, String) —

    IRI or String, if it’s a keyword

Raises:

See Also:



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# File 'lib/json/ld/context.rb', line 1304

def expand_iri(value,
  documentRelative: false,
  vocab: false,
  local_context: nil,
  defined: nil,
  as_string: false,
  **options
)
  return (value && as_string ? value.to_s : value) unless value.is_a?(String)

  return value if KEYWORDS.include?(value)
  return nil if value.match?(/^@[a-zA-Z]+$/)

  defined = defined || {} # if we initialized in the keyword arg we would allocate {} at each invokation, even in the 2 (common) early returns above.

  # If local context is not null, it contains a key that equals value, and the value associated with the key that equals value in defined is not true, then invoke the Create Term Definition subalgorithm, passing active context, local context, value as term, and defined. This will ensure that a term definition is created for value in active context during Context Processing.
  if local_context && local_context.has_key?(value) && !defined[value]
    create_term_definition(local_context, value, defined)
  end

  if (v_td = term_definitions[value]) && KEYWORDS.include?(v_td.id)
    return (as_string ? v_td.id.to_s : v_td.id)
  end

  # If active context has a term definition for value, and the associated mapping is a keyword, return that keyword.
  # If vocab is true and the active context has a term definition for value, return the associated IRI mapping.
  if (v_td = term_definitions[value]) && (vocab || KEYWORDS.include?(v_td.id))
    return (as_string ? v_td.id.to_s : v_td.id)
  end

  # If value contains a colon (:), it is either an absolute IRI or a compact IRI:
  if value[1..-1].to_s.include?(':')
    prefix, suffix = value.split(':', 2)

    # If prefix is underscore (_) or suffix begins with double-forward-slash (//), return value as it is already an absolute IRI or a blank node identifier.
    if prefix == '_'
      v = RDF::Node.new(namer.get_sym(suffix))
      return (as_string ? v.to_s : v)
    end
    if suffix.start_with?('//')
      v = RDF::URI(value)
      return (as_string ? v.to_s : v)
    end

    # If local context is not null, it contains a key that equals prefix, and the value associated with the key that equals prefix in defined is not true, invoke the Create Term Definition algorithm, passing active context, local context, prefix as term, and defined. This will ensure that a term definition is created for prefix in active context during Context Processing.
    if local_context && local_context.has_key?(prefix) && !defined[prefix]
      create_term_definition(local_context, prefix, defined)
    end

    # If active context contains a term definition for prefix, return the result of concatenating the IRI mapping associated with prefix and suffix.
    if (td = term_definitions[prefix]) && !td.id.nil? && td.prefix?
      return (as_string ? td.id.to_s : td.id) + suffix
    elsif RDF::URI(value).absolute?
      # Otherwise, if the value has the form of an absolute IRI, return it
      return (as_string ? value.to_s : RDF::URI(value))
    else
      # Otherwise, it is a relative IRI
    end
  end

  result = if vocab && self.vocab
    # If vocab is true, and active context has a vocabulary mapping, return the result of concatenating the vocabulary mapping with value.
    self.vocab + value
  elsif documentRelative && (base ||= self.base)
    # Otherwise, if document relative is true, set value to the result of resolving value against the base IRI. Only the basic algorithm in section 5.2 of [RFC3986] is used; neither Syntax-Based Normalization nor Scheme-Based Normalization are performed. Characters additionally allowed in IRI references are treated in the same way that unreserved characters are treated in URI references, per section 6.5 of [RFC3987].
    value = RDF::URI(value)
    value.absolute? ? value : RDF::URI(base).join(value)
  elsif local_context && RDF::URI(value).relative?
    # If local context is not null and value is not an absolute IRI, an invalid IRI mapping error has been detected and processing is aborted.
    raise JSON::LD::JsonLdError::InvalidIRIMapping, "not an absolute IRI: #{value}"
  else
    RDF::URI(value)
  end
  result && as_string ? result.to_s : result
end

#expand_value(property, value, useNativeTypes: false, rdfDirection: nil, **options) ⇒ Hash

If active property has a type mapping in the active context set to @id or @vocab, a JSON object with a single member @id whose value is the result of using the IRI Expansion algorithm on value is returned.

Otherwise, the result will be a JSON object containing an @value member whose value is the passed value. Additionally, an @type member will be included if there is a type mapping associated with the active property or an @language member if value is a string and there is language mapping associated with the active property.

Parameters:

  • property (String) —

    Associated property used to find coercion rules

  • value (Hash, String) —

    Value (literal or IRI) to be expanded

  • useNativeTypes (Boolean) (defaults to: false) —

    (false) use native representations

  • rdfDirection (Boolean) (defaults to: nil) —

    (nil) decode i18n datatype if i18n-datatype

  • options (Hash{Symbol => Object})

Returns:

  • (Hash) —

    Object representation of value

Raises:

  • (RDF::ReaderError) —

    if the iri cannot be expanded

See Also:



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# File 'lib/json/ld/context.rb', line 1602

def expand_value(property, value, useNativeTypes: false, rdfDirection: nil, **options)
  #log_debug("expand_value") {"property: #{property.inspect}, value: #{value.inspect}"}

  td = term_definitions.fetch(property, TermDefinition.new(property))

  # If the active property has a type mapping in active context that is @id, return a new JSON object containing a single key-value pair where the key is @id and the value is the result of using the IRI Expansion algorithm, passing active context, value, and true for document relative.
  if value.is_a?(String) && td.type_mapping == '@id'
    #log_debug("") {"as relative IRI: #{value.inspect}"}
    return {'@id' => expand_iri(value, documentRelative: true).to_s}
  end

  # If active property has a type mapping in active context that is @vocab, return a new JSON object containing a single key-value pair where the key is @id and the value is the result of using the IRI Expansion algorithm, passing active context, value, true for vocab, and true for document relative.
  if value.is_a?(String) && td.type_mapping == '@vocab'
    #log_debug("") {"as vocab IRI: #{value.inspect}"}
    return {'@id' => expand_iri(value, vocab: true, documentRelative: true).to_s}
  end

  value = RDF::Literal(value) if
    value.is_a?(Date) ||
    value.is_a?(DateTime) ||
    value.is_a?(Time)

  result = case value
  when RDF::URI, RDF::Node
    #log_debug("URI | BNode") { value.to_s }
    {'@id' => value.to_s}
  when RDF::Literal
    #log_debug("Literal") {"datatype: #{value.datatype.inspect}"}
    res = {}
    if value.datatype == RDF::URI(RDF.to_uri + "JSON") && processingMode('json-ld-1.1')
      # Value parsed as JSON
      # FIXME: MultiJson
      res['@value'] = ::JSON.parse(value.object)
      res['@type'] = '@json'
    elsif value.datatype.start_with?("https://www.w3.org/ns/i18n#") && rdfDirection == 'i18n-datatype' && processingMode('json-ld-1.1')
      lang, dir = value.datatype.fragment.split('_')
      res['@value'] = value.to_s
      unless lang.empty?
        if lang !~ /^[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*$/
          if options[:validate]
            raise JsonLdError::InvalidLanguageMapping, "rdf:language must be valid BCP47: #{lang.inspect}"
          else
            warn "rdf:language must be valid BCP47: #{lang.inspect}"
          end
        end
        res['@language'] = lang
      end
      res['@direction'] = dir
    elsif useNativeTypes && RDF_LITERAL_NATIVE_TYPES.include?(value.datatype)
      res['@value'] = value.object
      res['@type'] = uri(coerce(property)) if coerce(property)
    else
      value.canonicalize! if value.datatype == RDF::XSD.double
      res['@value'] = value.to_s
      if coerce(property)
        res['@type'] = uri(coerce(property)).to_s
      elsif value.has_datatype?
        res['@type'] = uri(value.datatype).to_s
      elsif value.has_language? || language(property)
        res['@language'] = (value.language || language(property)).to_s
        # FIXME: direction
      end
    end
    res
  else
    # Otherwise, initialize result to a JSON object with an @value member whose value is set to value.
    res = {'@value' => value}

    if td.type_mapping && !CONTAINERS_ID_VOCAB.include?(td.type_mapping.to_s)
      res['@type'] = td.type_mapping.to_s
    elsif value.is_a?(String)
      language = language(property)
      direction = direction(property)
      res['@language'] = language if language
      res['@direction'] = direction if direction
    end

    res
  end

  #log_debug("") {"=> #{result.inspect}"}
  result
rescue ::JSON::ParserError => e
  raise JSON::LD::JsonLdError::InvalidJsonLiteral, e.message
end

#find_definition(term) ⇒ Term

Find a term definition

Parameters:

  • term (Term, #to_s) —

    in unexpanded form

Returns:

  • (Term) 


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# File 'lib/json/ld/context.rb', line 1167

def find_definition(term)
  term.is_a?(TermDefinition) ? term : term_definitions[term.to_s]
end

#from_vocabulary(graph) ⇒ self

Build a context from an RDF::Vocabulary definition.

Examples:

building from an external vocabulary definition


g = RDF::Graph.load("http://schema.org/docs/schema_org_rdfa.html")

context = JSON::LD::Context.new.from_vocabulary(g,
      vocab: "http://schema.org/",
      prefixes: {schema: "http://schema.org/"},
      language: "en")

Parameters:

  • graph (RDF::Queryable)

Returns:

  • (self) 


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# File 'lib/json/ld/context.rb', line 1082

def from_vocabulary(graph)
  statements = {}
  ranges = {}

  # Add term definitions for each class and property not in schema:, and
  # for those properties having an object range
  graph.each do |statement|
    next if statement.subject.node?
    (statements[statement.subject] ||= []) << statement

    # Keep track of predicate ranges
    if [RDF::RDFS.range, RDF::SCHEMA.rangeIncludes].include?(statement.predicate)
      (ranges[statement.subject] ||= []) << statement.object
    end
  end

  # Add term definitions for each class and property not in vocab, and
  # for those properties having an object range
  statements.each do |subject, values|
    types = values.each_with_object([]) { |v, memo| memo << v.object if v.predicate == RDF.type }
    is_property = types.any? {|t| t.to_s.include?("Property")}

    term = subject.to_s.split(/[\/\#]/).last

    if !is_property
      # Ignore if there's a default voabulary and this is not a property
      next if vocab && subject.to_s.start_with?(vocab)

      # otherwise, create a term definition
      td = term_definitions[term] = TermDefinition.new(term, id: subject.to_s)
    else
      prop_ranges = ranges.fetch(subject, [])
      # If any range is empty or member of range includes rdfs:Literal or schema:Text
      next if vocab && prop_ranges.empty? ||
                       prop_ranges.include?(RDF::SCHEMA.Text) ||
                       prop_ranges.include?(RDF::RDFS.Literal)
      td = term_definitions[term] = TermDefinition.new(term, id: subject.to_s)

      # Set context typing based on first element in range
      case r = prop_ranges.first
      when RDF::XSD.string
        if self.default_language
          td.language_mapping = false
        end
        # FIXME: text direction
      when RDF::XSD.boolean, RDF::SCHEMA.Boolean, RDF::XSD.date, RDF::SCHEMA.Date,
        RDF::XSD.dateTime, RDF::SCHEMA.DateTime, RDF::XSD.time, RDF::SCHEMA.Time,
        RDF::XSD.duration, RDF::SCHEMA.Duration, RDF::XSD.decimal, RDF::SCHEMA.Number,
        RDF::XSD.float, RDF::SCHEMA.Float, RDF::XSD.integer, RDF::SCHEMA.Integer
        td.type_mapping = r
        td.simple = false
      else
        # It's an object range (includes schema:URL)
        td.type_mapping = '@id'
      end
    end
  end

  self
end

#inspect ⇒ Object 



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# File 'lib/json/ld/context.rb', line 1790

def inspect
  v = %w([Context)
  v << "base=#{base}" if base
  v << "vocab=#{vocab}" if vocab
  v << "processingMode=#{processingMode}" if processingMode
  v << "default_language=#{default_language}" if default_language
  v << "default_direction=#{default_direction}" if default_direction
  v << "previous_context" if previous_context
  v << "term_definitions[#{term_definitions.length}]=#{term_definitions}"
  v.join(" ") + "]"
end

#language(term) ⇒ String

Retrieve the language associated with a term, or the default language otherwise

Parameters:

  • term (Term, #to_s) —

    in unexpanded form

Returns:

  • (String) 


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# File 'lib/json/ld/context.rb', line 1241

def language(term)
  term = find_definition(term)
  lang = term && term.language_mapping
  lang.nil? ? @default_language : (lang == false ? nil : lang)
end

#merge(context) ⇒ Context

Merge in a context, creating a new context with updates from ‘context`

Parameters:

Returns:



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# File 'lib/json/ld/context.rb', line 696

def merge(context)
  c = self.dup.merge!(context)
  c.instance_variable_set(:@term_definitions, context.term_definitions.dup)
  c
end

#merge!(context) ⇒ self

Update context with definitions from ‘context`

Parameters:

Returns:

  • (self) 


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# File 'lib/json/ld/context.rb', line 707

def merge!(context)
  # FIXME: if new context removes the default language, this won't do anything
  self.default_language = context.default_language if context.default_language
  self.vocab = context.vocab if context.vocab
  self.base = context.base if context.base

  # Merge in Term Definitions
  term_definitions.merge!(context.term_definitions)
  @inverse_context = nil  # Re-build after term definitions set
  self
end

#nest(term) ⇒ String

Retrieve nest of a term. value of nest must be @nest or a term that resolves to @nest

Parameters:

  • term (Term, #to_s) —

    in unexpanded form

Returns:

  • (String) —

    Nesting term

Raises:

  • JsonLdError::InvalidNestValue if nesting term exists and is not a term resolving to ‘@nest` in the current context.



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# File 'lib/json/ld/context.rb', line 1223

def nest(term)
  term = find_definition(term)
  if term
    case term.nest
    when '@nest', nil
      term.nest
    else
      nest_term = find_definition(term.nest)
      raise JsonLdError::InvalidNestValue, "nest must a term resolving to @nest, was #{nest_term.inspect}" unless nest_term && nest_term.simple? && nest_term.id == '@nest'
      term.nest
    end
  end
end

#parse(local_context, remote_contexts: [], protected: false, override_protected: false, propagate: true) ⇒ Context

Create an Evaluation Context

When processing a JSON-LD data structure, each processing rule is applied using information provided by the active context. This section describes how to produce an active context.

The active context contains the active term definitions which specify how properties and values have to be interpreted as well as the current base IRI, the vocabulary mapping and the default language. Each term definition consists of an IRI mapping, a boolean flag reverse property, an optional type mapping or language mapping, and an optional container mapping. A term definition can not only be used to map a term to an IRI, but also to map a term to a keyword, in which case it is referred to as a keyword alias.

When processing, the active context is initialized without any term definitions, vocabulary mapping, or default language. If a local context is encountered during processing, a new active context is created by cloning the existing active context. Then the information from the local context is merged into the new active context. Given that local contexts may contain references to remote contexts, this includes their retrieval.

Parameters:

  • local_context (String, #read, Array, Hash, Context)
  • remote_contexts (Array<String>) (defaults to: [])
  • protected (Boolean) (defaults to: false) —

    Make defined terms protected (as if ‘@protected` were used).

  • override_protected (Boolean) (defaults to: false) —

    Protected terms may be cleared.

  • propagate (Boolean) (defaults to: true) —

    If false, retains any previously defined term, which can be rolled back when the descending into a new node object changes.

Returns:

Raises:

  • (JsonLdError) —

    on a remote context load error, syntax error, or a reference to a term which is not defined.

See Also:



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# File 'lib/json/ld/context.rb', line 533

def parse(local_context, remote_contexts: [], protected: false, override_protected: false, propagate: true)
  result = self.dup
  result.provided_context = local_context if self.empty?
  # Early check for @propagate, which can only appear in a local context
  propagate = local_context.is_a?(Hash) ? local_context.fetch('@propagate', propagate) : propagate
  result.previous_context ||= result.dup unless propagate

  local_context = as_array(local_context)

  local_context.each do |context|
    case context
    when nil
      # 3.1 If the `override_protected` is  false, and the active context contains protected terms, an error is raised.
      if override_protected || result.term_definitions.values.none?(&:protected?)
        null_context = Context.new(**options)
        null_context.previous_context = result unless propagate
        result = null_context
      else
        raise JSON::LD::JsonLdError::InvalidContextNullification,
              "Attempt to clear a context with protected terms"
      end
    when Context
       #log_debug("parse") {"context: #{context.inspect}"}
       result = context.dup
    when IO, StringIO
      #log_debug("parse") {"io: #{context}"}
      # Load context document, if it is an open file
      begin
        ctx = JSON.load(context)
        raise JSON::LD::JsonLdError::InvalidRemoteContext, "Context missing @context key" if @options[:validate] && ctx['@context'].nil?
        result = result.dup.parse(ctx["@context"] ? ctx["@context"].dup : {})
        result.provided_context = ctx["@context"] if [context] == local_context
        result
      rescue JSON::ParserError => e
        #log_debug("parse") {"Failed to parse @context from remote document at #{context}: #{e.message}"}
        raise JSON::LD::JsonLdError::InvalidRemoteContext, "Failed to parse remote context at #{context}: #{e.message}" if @options[:validate]
        self.dup
      end
    when String, RDF::URI
      #log_debug("parse") {"remote: #{context}, base: #{result.context_base || result.base}"}

      # 3.2.1) Set context to the result of resolving value against the base IRI which is established as specified in section 5.1 Establishing a Base URI of [RFC3986]. Only the basic algorithm in section 5.2 of [RFC3986] is used; neither Syntax-Based Normalization nor Scheme-Based Normalization are performed. Characters additionally allowed in IRI references are treated in the same way that unreserved characters are treated in URI references, per section 6.5 of [RFC3987].
      context = RDF::URI(result.context_base || options[:base]).join(context)
      context_canon = context.canonicalize
      context_canon.scheme == 'http' if context_canon.scheme == 'https'

      remote_contexts << context.to_s
      raise JsonLdError::ContextOverflow, "#{context}" if remote_contexts.length >= MAX_CONTEXTS_LOADED

      context_no_base = result.dup
      context_no_base.base = nil
      context_no_base.context_base = context.to_s

      if PRELOADED[context_canon.to_s]
        # If we have a cached context, merge it into the current context (result) and use as the new context
        #log_debug("parse") {"=> cached_context: #{context_canon.to_s.inspect}"}

        # If this is a Proc, then replace the entry with the result of running the Proc
        if PRELOADED[context_canon.to_s].respond_to?(:call)
          #log_debug("parse") {"=> (call)"}
          PRELOADED[context_canon.to_s] = PRELOADED[context_canon.to_s].call
        end
        context = context_no_base.merge!(PRELOADED[context_canon.to_s])
      else
        # Load context document, if it is a string
        begin
          context_opts = @options.merge(
            profile: 'http://www.w3.org/ns/json-ld#context',
            requestProfile: 'http://www.w3.org/ns/json-ld#context',
            base: nil)
          #context_opts.delete(:headers)
          JSON::LD::API.loadRemoteDocument(context.to_s, **context_opts) do |remote_doc|
            # 3.2.5) Dereference context. If the dereferenced document has no top-level JSON object with an @context member, an invalid remote context has been detected and processing is aborted; otherwise, set context to the value of that member.
            raise JsonLdError::InvalidRemoteContext, "#{context}" unless remote_doc.document.is_a?(Hash) && remote_doc.document.has_key?('@context')
            context = remote_doc.document['@context']
          end
        rescue JsonLdError::LoadingDocumentFailed => e
          #log_debug("parse") {"Failed to retrieve @context from remote document at #{context_no_base.context_base.inspect}: #{e.message}"}
          raise JsonLdError::LoadingRemoteContextFailed, "#{context_no_base.context_base}: #{e.message}", e.backtrace
        rescue JsonLdError
          raise
        rescue StandardError => e
          #log_debug("parse") {"Failed to retrieve @context from remote document at #{context_no_base.context_base.inspect}: #{e.message}"}
          raise JsonLdError::LoadingRemoteContextFailed, "#{context_no_base.context_base}: #{e.message}", e.backtrace
        end

        # 3.2.6) Set context to the result of recursively calling this algorithm, passing context no base for active context, context for local context, and remote contexts.
        context = context_no_base.parse(context, remote_contexts: remote_contexts.dup, protected: protected, override_protected: override_protected, propagate: propagate)
        PRELOADED[context_canon.to_s] = context.dup
        context.provided_context = result.provided_context
      end
      context.base ||= result.base
      result = context
      #log_debug("parse") {"=> provided_context: #{context.inspect}"}
    when Hash
      context = context.dup # keep from modifying a hash passed as a param

      # This counts on hash elements being processed in order
      {
        '@version'    => :processingMode=,
        '@import'     => nil,
        '@base'       => :base=,
        '@direction'   => :default_direction=,
        '@language'   => :default_language=,
        '@propagate'  => :propagate=,
        '@vocab'      => :vocab=,
      }.each do |key, setter|
        next unless context.has_key?(key)
        if key == '@import'
          # Retrieve remote context and merge the remaining context object into the result.
          raise JsonLdError::InvalidContextEntry, "@import may only be used in 1.1 mode}" if result.processingMode("json-ld-1.0")
          raise JsonLdError::InvalidImportValue, "@import must be a string: #{context['@import'].inspect}" unless context['@import'].is_a?(String)
          source = RDF::URI(result.context_base || result.base).join(context['@import'])
          begin
            context_opts = @options.merge(
              profile: 'http://www.w3.org/ns/json-ld#context',
              requestProfile: 'http://www.w3.org/ns/json-ld#context',
              base: nil)
            context_opts.delete(:headers)
            JSON::LD::API.loadRemoteDocument(source, **context_opts) do |remote_doc|
              # Dereference source. If the dereferenced document has no top-level JSON object with an @context member, an invalid remote context has been detected and processing is aborted; otherwise, set context to the value of that member.
              raise JsonLdError::InvalidRemoteContext, "#{source}" unless remote_doc.document.is_a?(Hash) && remote_doc.document.has_key?('@context')
              import_context = remote_doc.document['@context']
              raise JsonLdError::InvalidRemoteContext, "#{import_context.to_json} must be an object" unless import_context.is_a?(Hash)
              raise JsonLdError::InvalidContextEntry, "#{import_context.to_json} must not include @import entry" if import_context.has_key?('@import')
              context.delete(key)
              context = import_context.merge(context)
            end
          rescue JsonLdError::LoadingDocumentFailed => e
            raise JsonLdError::LoadingRemoteContextFailed, "#{source}: #{e.message}", e.backtrace
          rescue JsonLdError
            raise
          rescue StandardError => e
            raise JsonLdError::LoadingRemoteContextFailed, "#{source}: #{e.message}", e.backtrace
          end
        else
          result.send(setter, context[key], remote_contexts: remote_contexts, protected: context.fetch('@protected', protected))
        end
        context.delete(key)
      end

      defined = {}

      # For each key-value pair in context invoke the Create Term Definition subalgorithm, passing result for active context, context for local context, key, and defined
      context.each_key do |key|
        # ... where key is not @base, @vocab, @language, or @version
        result.create_term_definition(context, key, defined,
                                      override_protected: override_protected,
                                      protected: context.fetch('@protected', protected)) unless NON_TERMDEF_KEYS.include?(key)
      end
    else
      # 3.3) If context is not a JSON object, an invalid local context error has been detected and processing is aborted.
      raise JsonLdError::InvalidLocalContext, "must be a URL, JSON object or array of same: #{context.inspect}"
    end
  end
  result
end

#processingMode(expected = nil) ⇒ String

Retrieve, or check processing mode.

  • With no arguments, retrieves the current set processingMode.

  • With an argument, verifies that the processingMode is at least that provided, either as an integer, or a string of the form “json-ld-1.x”

  • If expecting 1.1, and not set, it has the side-effect of setting mode to json-ld-1.1.

Parameters:

  • expected (String, Number) (defaults to: nil) —

    (nil)

Returns:

  • (String) 


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# File 'lib/json/ld/context.rb', line 444

def processingMode(expected = nil)
  case expected
  when 1.0, 'json-ld-1.0'
    @processingMode == 'json-ld-1.0'
  when 1.1, 'json-ld-1.1'
    @processingMode ||= 'json-ld-1.1'
    @processingMode == 'json-ld-1.1'
  when nil
    @processingMode
  else
    false
  end
end

#processingMode=(value = nil, **options) ⇒ String

Set processing mode.

  • With an argument, verifies that the processingMode is at least that provided, either as an integer, or a string of the form “json-ld-1.x”

If contex has a @version member, it’s value MUST be 1.1, otherwise an “invalid @version value” has been detected, and processing is aborted. If processingMode has been set, and it is not “json-ld-1.1”, a “processing mode conflict” has been detecting, and processing is aborted.

Parameters:

  • expected (String, Number)

Returns:

  • (String)

Raises:



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# File 'lib/json/ld/context.rb', line 469

def processingMode=(value = nil, **options)
  value = "json-ld-1.1" if value == 1.1
  case value
  when "json-ld-1.0", "json-ld-1.1"
    if @processingMode && @processingMode != value
      raise JsonLdError::ProcessingModeConflict, "#{value} not compatible with #{@processingMode}"
    end
    @processingMode = value
  else
    raise JsonLdError::InvalidVersionValue, value.inspect
  end
end

#propagate=(value, **options) ⇒ Object

Set propagation @note: by the time this is called, the work has already been done.

Parameters:

  • value (Boolean)

Raises:



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# File 'lib/json/ld/context.rb', line 508

def propagate=(value, **options)
  raise JsonLdError::InvalidContextEntry, "@propagate may only be set in 1.1 mode" if processingMode("json-ld-1.0")
  raise JsonLdError::InvalidPropagateValue, "@propagate must be boolean valued: #{value.inspect}" unless value.is_a?(TrueClass) || value.is_a?(FalseClass)
  value
end

#reverse?(term) ⇒ Boolean

Is this a reverse term

Parameters:

  • term (Term, #to_s) —

    in unexpanded form

Returns:

  • (Boolean) 


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# File 'lib/json/ld/context.rb', line 1261

def reverse?(term)
  term = find_definition(term)
  term && term.reverse_property
end

#reverse_term(term) ⇒ Term

Given a term or IRI, find a reverse term definition matching that term. If the term is already reversed, find a non-reversed version.

Parameters:

  • term (Term, #to_s)

Returns:

  • (Term) —

    related term definition



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# File 'lib/json/ld/context.rb', line 1271

def reverse_term(term)
  # Direct lookup of term
  term = term_definitions[term.to_s] if term_definitions.has_key?(term.to_s) && !term.is_a?(TermDefinition)

  # Lookup term, assuming term is an IRI
  unless term.is_a?(TermDefinition)
    td = term_definitions.values.detect {|t| t.id == term.to_s}

    # Otherwise create a temporary term definition
    term = td || TermDefinition.new(term.to_s, id: expand_iri(term, vocab:true))
  end

  # Now, return a term, which reverses this term
  term_definitions.values.detect {|t| t.id == term.id && t.reverse_property != term.reverse_property}
end

#serialize(**options) ⇒ Hash

Generate @context

If a context was supplied in global options, use that, otherwise, generate one from this representation.

Parameters:

  • options (Hash{Symbol => Object}) —

    ({})

Returns:

  • (Hash) 


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# File 'lib/json/ld/context.rb', line 1033

def serialize(**options)
  # FIXME: not setting provided_context now
  use_context = case provided_context
  when String, RDF::URI
    #log_debug "serlialize: reuse context: #{provided_context.inspect}"
    provided_context.to_s
  when Hash, Array
    #log_debug "serlialize: reuse context: #{provided_context.inspect}"
    provided_context
  else
    #log_debug("serlialize: generate context")
    #log_debug("") {"=> context: #{inspect}"}
    ctx = {}
    ctx['@base'] = base.to_s if base && base != doc_base
    ctx['@direction'] = default_direction.to_s if default_direction
    ctx['@language'] = default_language.to_s if default_language
    ctx['@vocab'] = vocab.to_s if vocab

    # Term Definitions
    term_definitions.keys.each do |term|
      defn = term_definitions[term].to_context_definition(self)
      ctx[term] = defn if defn
    end

    #log_debug("") {"start_doc: context=#{ctx.inspect}"}
    ctx
  end

  # Return hash with @context, or empty
  r = {}
  r['@context'] = use_context unless use_context.nil? || use_context.empty?
  r
end

#set_mapping(term, value) ⇒ TermDefinition

Set term mapping

Parameters:

  • term (#to_s)
  • value (RDF::URI, String, nil)

Returns:



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# File 'lib/json/ld/context.rb', line 1149

def set_mapping(term, value)
  #log_debug("") {"map #{term.inspect} to #{value.inspect}"}
  term = term.to_s
  term_definitions[term] = TermDefinition.new(term, id: value, simple: true, prefix: (value.to_s.end_with?(*PREFIX_URI_ENDINGS)))
  term_definitions[term].simple = true

  term_sym = term.empty? ? "" : term.to_sym
  iri_to_term.delete(term_definitions[term].id.to_s) if term_definitions[term].id.is_a?(String)
  @options[:prefixes][term_sym] = value if @options.has_key?(:prefixes)
  iri_to_term[value.to_s] = term
  term_definitions[term]
end

#to_rb(*aliases) ⇒ String

Turn this into a source for a new instantiation

Parameters:

  • aliases (Array<String>) —

    Other URLs to alias when preloading

Returns:

  • (String) 


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# File 'lib/json/ld/context.rb', line 1767

def to_rb(*aliases)
  canon_base = RDF::URI(context_base).canonicalize
  defn = []

  defn << "base: #{self.base.to_s.inspect}" if self.base
  defn << "language: #{self.default_language.inspect}" if self.default_language
  defn << "vocab: #{self.vocab.to_s.inspect}" if self.vocab
  defn << "processingMode: #{self.processingMode.inspect}" if self.processingMode
  term_defs = term_definitions.map do |term, td|
    "      " + term.inspect + " => " + td.to_rb
  end.sort
  defn << "term_definitions: {\n#{term_defs.join(",\n")    }\n    }" unless term_defs.empty?
  %(# -*- encoding: utf-8 -*-
  # frozen_string_literal: true
  # This file generated automatically from #{context_base}
  require 'json/ld'
  class JSON::LD::Context
  ).gsub(/^      /, '') +
  %[  add_preloaded("#{canon_base}") do\n    new(] + defn.join(", ")  + ")\n  end\n" +
  aliases.map {|a| %[  alias_preloaded("#{a}", "#{canon_base}")\n]}.join("") +
  "end\n"
end