Class: JSON::LD::ContentNegotiation
- Defined in:
- vendor/bundler/ruby/3.3.0/bundler/gems/json-ld-f1de87658826/lib/json/ld/conneg.rb
Overview
Rack middleware for JSON-LD content negotiation.
Uses HTTP Content Negotiation to serialize Array
and Hash
results as JSON-LD using 'profile' accept-params to invoke appropriate JSON-LD API methods.
Allows black-listing and white-listing of two-part profiles where the second part denotes a URL of a context or frame. (See Writer.accept?)
Works along with rack-linkeddata
for serializing data which is not in the form of an RDF::Repository
.
Constant Summary collapse
- VARY =
{ 'Vary' => 'Accept' }.freeze
Instance Attribute Summary collapse
- #app ⇒ #call readonly
Class Method Summary collapse
-
.registered(app)
- Registers JSON::LD::Rack, suitable for Sinatra application * adds helpers.
Instance Method Summary collapse
-
#accept_entry(entry) ⇒ Object
protected
Returns an array of quality, number of '*' in content-type, and number of non-'q' parameters.
-
#call(env) ⇒ Array(Integer, Hash, #each)
Handles a Rack protocol request.
-
#find_content_type_for_media_range(media_range) ⇒ String?
protected
Returns a content type appropriate for the given
media_range
, returnsnil
ifmedia_range
contains a wildcard subtype that is not mapped. -
#http_error(code, message = nil, headers = {}) ⇒ Array(Integer, Hash, #each)
protected
Outputs an HTTP
4xx
or5xx
response. -
#initialize(app) ⇒ ContentNegotiation
constructor
A new instance of ContentNegotiation.
-
#not_acceptable(message = nil) ⇒ Array(Integer, Hash, #each)
protected
Outputs an HTTP
406 Not Acceptable
response. -
#parse_accept_header(header) ⇒ Array<String>
protected
Parses an HTTP
Accept
header, returning an array of MIME content types ordered by the precedence rules defined in HTTP/1.1 §14.1. -
#serialize(env, status, headers, body) ⇒ Array(Integer, Hash, #each)
Serializes objects as JSON-LD.
Constructor Details
#initialize(app) ⇒ ContentNegotiation
Returns a new instance of ContentNegotiation.
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# File 'vendor/bundler/ruby/3.3.0/bundler/gems/json-ld-f1de87658826/lib/json/ld/conneg.rb', line 42 def initialize(app) @app = app end |
Instance Attribute Details
#app ⇒ #call (readonly)
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# File 'vendor/bundler/ruby/3.3.0/bundler/gems/json-ld-f1de87658826/lib/json/ld/conneg.rb', line 29 def app @app end |
Class Method Details
.registered(app)
This method returns an undefined value.
- Registers JSON::LD::Rack, suitable for Sinatra application
- adds helpers
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# File 'vendor/bundler/ruby/3.3.0/bundler/gems/json-ld-f1de87658826/lib/json/ld/conneg.rb', line 37 def self.registered(app) = {} app.use(JSON::LD::Rack, **) end |
Instance Method Details
#accept_entry(entry) ⇒ Object (protected)
Returns an array of quality, number of '*' in content-type, and number of non-'q' parameters
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# File 'vendor/bundler/ruby/3.3.0/bundler/gems/json-ld-f1de87658826/lib/json/ld/conneg.rb', line 155 def accept_entry(entry) type, * = entry.split(';').map(&:strip) quality = 0 # we sort smallest first .delete_if { |e| quality = 1 - e[2..].to_f if e.start_with? 'q=' } [.unshift(type).join(';'), [quality, type.count('*'), 1 - .size]] end |
#call(env) ⇒ Array(Integer, Hash, #each)
Handles a Rack protocol request. Parses Accept header to find appropriate mime-type and sets content_type accordingly.
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# File 'vendor/bundler/ruby/3.3.0/bundler/gems/json-ld-f1de87658826/lib/json/ld/conneg.rb', line 53 def call(env) response = app.call(env) body = response[2].respond_to?(:body) ? response[2].body : response[2] case body when Array, Hash response[2] = body # Put it back in the response, it might have been a proxy serialize(env, *response) else response end end |
#find_content_type_for_media_range(media_range) ⇒ String? (protected)
Returns a content type appropriate for the given media_range
,
returns nil
if media_range
contains a wildcard subtype
that is not mapped.
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# File 'vendor/bundler/ruby/3.3.0/bundler/gems/json-ld-f1de87658826/lib/json/ld/conneg.rb', line 169 def find_content_type_for_media_range(media_range) media_range = media_range.sub('*/*', 'application/ld+json') if media_range.to_s.start_with?('*/*') if media_range.to_s.start_with?('application/*') media_range = media_range.sub('application/*', 'application/ld+json') end if media_range.to_s.start_with?('application/json') media_range = media_range.sub('application/json', 'application/ld+json') end media_range.start_with?('application/ld+json') ? media_range : nil end |
#http_error(code, message = nil, headers = {}) ⇒ Array(Integer, Hash, #each) (protected)
Outputs an HTTP 4xx
or 5xx
response.
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# File 'vendor/bundler/ruby/3.3.0/bundler/gems/json-ld-f1de87658826/lib/json/ld/conneg.rb', line 199 def http_error(code, = nil, headers = {}) = [code, Rack::Utils::HTTP_STATUS_CODES[code]].join(' ') + (.nil? ? "\n" : " (#{})\n") [code, { 'Content-Type' => "text/plain" }.merge(headers), []] end |
#not_acceptable(message = nil) ⇒ Array(Integer, Hash, #each) (protected)
Outputs an HTTP 406 Not Acceptable
response.
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# File 'vendor/bundler/ruby/3.3.0/bundler/gems/json-ld-f1de87658826/lib/json/ld/conneg.rb', line 188 def not_acceptable( = nil) http_error(406, , VARY) end |
#parse_accept_header(header) ⇒ Array<String> (protected)
Parses an HTTP Accept
header, returning an array of MIME content
types ordered by the precedence rules defined in HTTP/1.1 §14.1.
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# File 'vendor/bundler/ruby/3.3.0/bundler/gems/json-ld-f1de87658826/lib/json/ld/conneg.rb', line 145 def parse_accept_header(header) entries = header.to_s.split(',') entries = entries .map { |e| accept_entry(e) } .sort_by(&:last) .map(&:first) entries.map { |e| find_content_type_for_media_range(e) }.compact end |
#serialize(env, status, headers, body) ⇒ Array(Integer, Hash, #each)
Serializes objects as JSON-LD. Defaults to expanded form, other forms
determined by presense of profile
in accept-parms.
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# File 'vendor/bundler/ruby/3.3.0/bundler/gems/json-ld-f1de87658826/lib/json/ld/conneg.rb', line 73 def serialize(env, status, headers, body) # This will only return json-ld content types, possibly with parameters content_types = parse_accept_header(env['HTTP_ACCEPT'] || 'application/ld+json') content_types = content_types.select do |content_type| _, *params = content_type.split(';').map(&:strip) accept_params = params.inject({}) do |memo, pv| p, v = pv.split('=').map(&:strip) memo.merge(p.downcase.to_sym => v.sub(/^["']?([^"']*)["']?$/, '\1')) end JSON::LD::Writer.accept?(accept_params) end if content_types.empty? not_acceptable("No appropriate combinaion of media-type and parameters found") else ct, *params = content_types.first.split(';').map(&:strip) accept_params = params.inject({}) do |memo, pv| p, v = pv.split('=').map(&:strip) memo.merge(p.downcase.to_sym => v.sub(/^["']?([^"']*)["']?$/, '\1')) end # Determine API method from profile profile = accept_params[:profile].to_s.split # Get context from Link header links = LinkHeader.parse(env['HTTP_LINK']) context = begin links.find_link(['rel', JSON_LD_NS + "context"]).href rescue StandardError nil end frame = begin links.find_link(['rel', JSON_LD_NS + "frame"]).href rescue StandardError nil end if profile.include?(JSON_LD_NS + "framed") && frame.nil? return not_acceptable("framed profile without a frame") end # accept? already determined that there are appropriate contexts # If profile also includes a URI which is not a namespace, use it for compaction. context ||= Writer.default_context if profile.include?(JSON_LD_NS + "compacted") result = if profile.include?(JSON_LD_NS + "flattened") API.flatten(body, context) elsif profile.include?(JSON_LD_NS + "framed") API.frame(body, frame) elsif context API.compact(body, context) elsif profile.include?(JSON_LD_NS + "expanded") API.(body) else body end headers = headers.merge(VARY).merge('Content-Type' => ct) [status, headers, [result.to_json]] end rescue StandardError http_error(500, $ERROR_INFO.) end |