Module: SPARQL::Results

Included in:
RDF::Query::Solutions
Defined in:
vendor/bundler/ruby/2.7.0/bundler/gems/sparql-cd4915d97d78/lib/sparql/results.rb

Overview

Generate SPARQL Results as Boolean, XML or JSON

This module is a mixin for RDF::Query::Solutions

Constant Summary collapse

MIME_TYPES =
{
  json: 'application/sparql-results+json',
  html: 'text/html',
  :xml  => 'application/sparql-results+xml',
  csv: 'text/csv',
  tsv: 'text/tab-separated-values'
}

Instance Method Summary collapse

Instance Method Details

#to_csvString

Generate Solutions as CSV



143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
# File 'vendor/bundler/ruby/2.7.0/bundler/gems/sparql-cd4915d97d78/lib/sparql/results.rb', line 143

def to_csv
  require 'csv' unless defined?(::CSV)
  bnode_map = {}
  bnode_gen = "_:a"
  CSV.generate(row_sep: "\r\n") do |csv|
    csv << variable_names.to_a
    self.each do |solution|
      csv << variable_names.map do |n|
        case term = solution[n]
        when RDF::Node then bnode_map[term] ||=
          begin
            this = bnode_gen
            bnode_gen = bnode_gen.succ
            this
          end
        else
          solution[n].to_s.strip
        end
      end
    end
  end
end

#to_htmlString

Generate Solutions as HTML



117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
# File 'vendor/bundler/ruby/2.7.0/bundler/gems/sparql-cd4915d97d78/lib/sparql/results.rb', line 117

def to_html
  require 'builder' unless defined?(::Builder)
  
  xml = ::Builder::XmlMarkup.new(indent: 2)
  xml.table(class: "sparql") do
    xml.tbody do
      xml.tr do
        variable_names.each do |n|
          xml.th(n.to_s)
        end
      end
      self.each do |solution|
        xml.tr do
          variable_names.each do |n|
            xml.td(RDF::NTriples.serialize(solution[n]))
          end
        end
      end
    end
  end
end

#to_jsonString

Generate Solutions as JSON



18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
# File 'vendor/bundler/ruby/2.7.0/bundler/gems/sparql-cd4915d97d78/lib/sparql/results.rb', line 18

def to_json
  require 'json' unless defined?(::JSON)

  format = ->(value) do
    case value
    when RDF::URI then {type: "uri", value: value.to_s }
    when RDF::Node then {type: "bnode", value: value.id }
    when RDF::Literal
      if value.datatype?
        {type: "typed-literal", datatype: value.datatype.to_s, value: value.to_s }
      elsif value.language?
        {type: "literal", "xml:lang" => value.language.to_s, value: value.to_s }
      else
        {type: "literal", value: value.to_s }
      end
    when RDF::Statement
      {
        type: 'triple',
        value: {
          s: format.call(value.subject),
          p: format.call(value.predicate),
          o: format.call(value.object)
        }
      }
    end
  end

  bindings = self.map do |solution|
    variable_names.inject({}) do |memo, n|
      rep = format.call(solution[n])
      rep ? memo.merge(n => rep) : memo
    end
  end

  {
    :head     => { vars: variable_names },
    :results  => { bindings: bindings}
  }.to_json
end

#to_tsvString

Generate Solutions as TSV



169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
# File 'vendor/bundler/ruby/2.7.0/bundler/gems/sparql-cd4915d97d78/lib/sparql/results.rb', line 169

def to_tsv
  require 'csv' unless defined?(::CSV)
  results = [
    variable_names.map {|v| "?#{v}"}.join("\t")
  ] + self.map do |solution|
    variable_names.map do |n|
      case term = solution[n]
      when RDF::Literal::Integer, RDF::Literal::Decimal, RDF::Literal::Double
        term.canonicalize.to_s
      when nil
        ""
      else
        RDF::NTriples.serialize(term).strip
      end
    end.join("\t")
  end
  results.join("\n") + "\n"
end

#to_xmlString

Generate Solutions as XML



62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
# File 'vendor/bundler/ruby/2.7.0/bundler/gems/sparql-cd4915d97d78/lib/sparql/results.rb', line 62

def to_xml
  require 'builder' unless defined?(::Builder)
  
  xml = ::Builder::XmlMarkup.new(indent: 2)
  xml.instruct!

  format = ->(s) do
    case s
    when RDF::URI
      xml.uri(s.to_s)
    when RDF::Node
      xml.bnode(s.id)
    when RDF::Literal
      if s.datatype?
        xml.literal(s.to_s, "datatype" => s.datatype.to_s)
      elsif s.language
        xml.literal(s.to_s, "xml:lang" => s.language.to_s)
      else
        xml.literal(s.to_s)
      end
    when RDF::Statement
      xml.triple do
        xml.s {format.call(s.subject)}
        xml.p {format.call(s.predicate)}
        xml.o {format.call(s.object)}
      end
    end
  end

  xml.sparql(xmlns: "http://www.w3.org/2005/sparql-results#") do
    xml.head do
      variable_names.each do |n|
        xml.variable(name: n)
      end
    end
    xml.results do
      self.each do |solution|
        xml.result do
          variable_names.each do |n|
            s = solution[n]
            next unless s
            xml.binding(name: n) do
              format.call(s)
            end
          end
        end
      end
    end
  end
end