Class: JSON::LD::Writer
- Inherits:
-
RDF::Writer
- Object
- RDF::Writer
- JSON::LD::Writer
- Includes:
- StreamingWriter, Utils, RDF::Util::Logger
- Defined in:
- lib/json/ld/writer.rb
Overview
A JSON-LD parser in Ruby.
Note that the natural interface is to write a whole graph at a time. Writing statements or Triples will create a graph to add them to and then serialize the graph.
The writer will add prefix definitions, and use them for creating @context definitions, and minting CURIEs
Select the :expand option to output JSON-LD in expanded form
Instance Attribute Summary collapse
-
#context ⇒ Context
readonly
Context used to load and administer contexts.
-
#graph ⇒ RDF::Graph
readonly
Graph of statements serialized.
Class Method Summary collapse
-
.options ⇒ Object
JSON-LD Writer options.
Instance Method Summary collapse
-
#initialize(output = $stdout, options = {}) {|writer| ... } ⇒ Writer
constructor
Initializes the RDF-LD writer instance.
-
#write_epilogue ⇒ void
Outputs the Serialized JSON-LD representation of all stored statements.
-
#write_prologue ⇒ void
Necessary for streaming.
-
#write_quad(subject, predicate, object, graph_name) ⇒ void
Outputs the N-Quads representation of a statement.
-
#write_triple(subject, predicate, object) ⇒ void
abstract
Addes a triple to be serialized.
Methods included from Utils
#add_value, #as_resource, #blank_node?, #compare_values, #has_property, #has_value, #index?, #list?, #node?, #node_or_ref?, #node_reference?, #value?
Methods included from StreamingWriter
#stream_epilogue, #stream_prologue, #stream_statement
Constructor Details
#initialize(output = $stdout, options = {}) {|writer| ... } ⇒ Writer
Initializes the RDF-LD writer instance.
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# File 'lib/json/ld/writer.rb', line 131 def initialize(output = $stdout, = {}, &block) [:base_uri] ||= [:base] if .has_key?(:base) [:base] ||= [:base_uri] if .has_key?(:base_uri) super do @repo = RDF::Repository.new if block_given? case block.arity when 0 then instance_eval(&block) else block.call(self) end end end end |
Instance Attribute Details
#context ⇒ Context (readonly)
Returns context used to load and administer contexts.
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# File 'lib/json/ld/writer.rb', line 68 def context @context end |
#graph ⇒ RDF::Graph (readonly)
Returns Graph of statements serialized.
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# File 'lib/json/ld/writer.rb', line 64 def graph @graph end |
Class Method Details
.options ⇒ Object
JSON-LD Writer options
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# File 'lib/json/ld/writer.rb', line 73 def self. super + [ RDF::CLI::Option.new( symbol: :compactArrays, datatype: TrueClass, on: ["--compact-arrays"], description: "Replaces arrays with just one element with that element during compaction.") {true}, RDF::CLI::Option.new( symbol: :context, datatype: RDF::URI, on: ["--context CONTEXT"], description: "Context to use when serializing. Constructed context for native serialization.") {|arg| RDF::URI(arg)}, RDF::CLI::Option.new( symbol: :frame, datatype: RDF::URI, on: ["--frame FRAME"], description: "Frame to use when serializing.") {|arg| RDF::URI(arg)}, RDF::CLI::Option.new( symbol: :stream, datatype: TrueClass, on: ["--stream"], description: "Do not attempt to optimize graph presentation, suitable for streaming large graphs.") {true}, RDF::CLI::Option.new( symbol: :useRdfType, datatype: TrueClass, on: ["--use-rdf-type"], description: "Treat `rdf:type` like a normal property instead of using `@type`.") {true}, ] end |
Instance Method Details
#write_epilogue ⇒ void
This method returns an undefined value.
Outputs the Serialized JSON-LD representation of all stored statements.
If provided a context or prefixes, we’ll create a context and use it to compact the output. Otherwise, we return un-compacted JSON-LD
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# File 'lib/json/ld/writer.rb', line 189 def write_epilogue if @options[:stream] stream_epilogue else log_debug("writer") { "serialize #{@repo.count} statements, #{@options.inspect}"} result = API.fromRdf(@repo, @options) # If we were provided a context, or prefixes, use them to compact the output context = RDF::Util::File.open_file(@options[:context]) if @options[:context].is_a?(String) context ||= @options[:context] context ||= if @options[:prefixes] || @options[:language] || @options[:standard_prefixes] ctx = Context.new(@options) ctx.language = @options[:language] if @options[:language] @options[:prefixes].each do |prefix, iri| ctx.set_mapping(prefix, iri) if prefix && iri end if @options[:prefixes] ctx end # Rename BNodes to uniquify them, if necessary if [:unique_bnodes] result = API.flatten(result, context, @options) end frame = RDF::Util::File.open_file(@options[:frame]) if @options[:frame].is_a?(String) if frame ||= @options[:frame] # Perform framing, if given a frame log_debug("writer") { "frame result"} result = API.frame(result, frame, @options) elsif context # Perform compaction, if we have a context log_debug("writer") { "compact result"} result = API.compact(result, context, @options) end @output.write(result.to_json(JSON_STATE)) end super end |
#write_prologue ⇒ void
This method returns an undefined value.
Necessary for streaming
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# File 'lib/json/ld/writer.rb', line 176 def write_prologue stream_prologue if @options[:stream] super end |
#write_quad(subject, predicate, object, graph_name) ⇒ void
This method returns an undefined value.
Outputs the N-Quads representation of a statement.
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# File 'lib/json/ld/writer.rb', line 164 def write_quad(subject, predicate, object, graph_name) statement = RDF::Statement.new(subject, predicate, object, graph_name: graph_name) if @options[:stream] stream_statement(statement) else @repo.insert(statement) end end |
#write_triple(subject, predicate, object) ⇒ void
This method returns an undefined value.
Addes a triple to be serialized
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# File 'lib/json/ld/writer.rb', line 153 def write_triple(subject, predicate, object) write_quad(subject, predicate, object, nil) end |