map rdf export (fixes #1015) (#1036)

* simple rdf export of maps

* register ttl mime type

* owl

* mm

* fix up export service

* implement base url thing whoo

* add more rdf fields

* fix rdf syntax errors

* hide unused fields in rdf

* some code climate fixes

* update ontology a bit more

* syntax fix

* typo

app/controllers/maps_controller.rb

@@ -20,6 +20,7 @@ class MapsController < ApplicationController
       end
       format.json { render json: @map }
       format.csv { redirect_to action: :export, format: :csv }
+      format.ttl { redirect_to action: :export, format: :ttl }
     end
   end
 
@@ -90,10 +91,12 @@ class MapsController < ApplicationController
 
   # GET maps/:id/export
   def export
-    exporter = MapExportService.new(current_user, @map)
+    exporter = MapExportService.new(current_user, @map, base_url: request.base_url)
+
     respond_to do |format|
       format.json { render json: exporter.json }
       format.csv { send_data exporter.csv }
+      format.ttl { render text: exporter.rdf }
     end
   end
 

app/models/synapse.rb

@@ -51,6 +51,18 @@ class Synapse < ApplicationRecord
     super(methods: [:user_name, :user_image, :collaborator_ids])
   end
 
+  def as_rdf
+    output = ''
+    output += %(d:synapse_#{id} a mm:Synapse ;\n)
+    output += %(  mm:topic1 d:topic_#{topic1_id} ;\n)
+    output += %(  mm:topic2 d:topic_#{topic2_id} ;\n)
+    output += %(  mm:direction "#{category}" ;\n)
+    output += %(  rdfs:comment "#{desc}" ;\n) if desc.present?
+    output[-2] = '.'
+    output += %(\n)
+    output
+  end
+
   def after_updated
     attrs = ['desc', 'category', 'permission', 'defer_to_map_id']
     if attrs.any? {|k| changed_attributes.key?(k)}

app/models/topic.rb

@@ -82,6 +82,19 @@ class Topic < ApplicationRecord
              map_count: map_count(options[:user]), synapse_count: synapse_count(options[:user]))
   end
 
+  def as_rdf
+    output = ''
+    output += %(d:topic_#{id} a mm:Topic ;\n)
+    output += %(  rdfs:label "#{name}" ;\n)
+    output += %(  rdfs:comment "#{desc}" ;\n) if desc.present?
+    output += %(  foaf:homepage <#{link}> ;\n) if link.present?
+    output += %(  mm:mapper d:mapper_#{user_id} ;\n)
+    output += %(  mm:metacode "#{metacode.name}" ;\n)
+    output[-2] = '.' # change last ; to a .
+    output += %(\n)
+    output
+  end
+
   def collaborator_ids
     if defer_to_map
       defer_to_map.editors.select { |mapper| mapper != user }.map(&:id)

app/models/user.rb

@@ -67,6 +67,17 @@ class User < ApplicationRecord
     json
   end
 
+  def as_rdf(opts = {})
+    base_url = opts[:base_url] || 'https://metamaps.cc'
+    output = ''
+    output += %(d:mapper_#{id} a foaf:OnlineAccount ;\n)
+    output += %(  foaf:accountName "#{name}" ;\n)
+    output += %(  foaf:accountServiceHomepage "#{base_url}/mapper/#{id}" ;\n)
+    output[-2] = '.' # change last ; to a .
+    output += %(\n)
+    output
+  end
+
   def all_accessible_maps
     maps + shared_maps
   end

app/services/map_export_service.rb

@@ -1,9 +1,11 @@
 # frozen_string_literal: true
 class MapExportService
-  attr_reader :user, :map
-  def initialize(user, map)
+  attr_reader :user, :map, :base_url
+
+  def initialize(user, map, opts = {})
     @user = user
     @map = map
+    @base_url = opts[:base_url] || 'https://metamaps.cc'
   end
 
   def json
@@ -22,6 +24,25 @@ class MapExportService
     end
   end
 
+  def rdf
+    output = ''
+    output += "PREFIX d: <#{base_url}/maps/#{map.id}>\n"
+    output += "PREFIX mm: <#{base_url}/owl/map.owl.ttl>\n"
+    output += "PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>\n"
+    output += "PREFIX foaf: <http://xmlns.com/foaf/0.1/>\n"
+    output += "\n"
+    map.contributors.each do |mapper|
+      output += mapper.as_rdf(base_url: base_url)
+    end
+    map.topics.each do |topic|
+      output += topic.as_rdf
+    end
+    map.synapses.each do |synapse|
+      output += synapse.as_rdf
+    end
+    output
+  end
+
   private
 
   def topic_headings

config/initializers/mime_types.rb

@@ -3,3 +3,6 @@
 
 # Add new mime types for use in respond_to blocks:
 # Mime::Type.register "text/richtext", :rtf
+
+# RDF export
+Mime::Type.register 'text/turtle', :ttl

public/owl/map.owl.ttl

@@ -0,0 +1,40 @@
+@prefix owl: <http://www.w3.org/2002/07/owl#> .
+@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+
+@prefix :   <http://metamaps.cc/owl/map.owl.ttl#> .
+@prefix mm:   <http://metamaps.cc/owl/map.owl.ttl#> .
+
+: a owl:Ontology ;
+	rdfs:label "Metamaps Map"@en .
+
+mm:Topic a owl:Class ;
+	rdfs:label "One topic on a metamap"@en .
+
+mm:Synapse a owl:Class ;
+  rdfs:label "Link between two topics on a metamap"@en .
+
+mm:topic1 a owl:ObjectProperty ;
+	a owl:FunctionalProperty ;
+	rdfs:label "first topic of a synapse"@en ;
+	rdfs:domain mm:Synapse ;
+	rdfs:range mm:Topic .
+
+mm:topic2 a owl:ObjectProperty ;
+	a owl:FunctionalProperty ;
+	rdfs:label "second topic of a synapse"@en ;
+	rdfs:domain mm:Topic ;
+	rdfs:range mm:Topic .
+
+mm:mapper a owl:ObjectProperty ;
+  a owl:FunctionalProperty ;
+  rdfs:label "Metamaps user who created this topic"@en ;
+  rdfs:domain mm:Topic ;
+  rdfs:range foaf:OnlineAccount .
+
+mm:direction a owl:ObjectProperty ;
+  a owl:FunctionalProperty ;
+  rdfs:label "from-to, both, or none"@en ;
+  rdfs:domain mm:Synapse ;
+  rdfs:range [ owl:oneOf mm:from-to, mm:both, mm:none ] .