hide unused fields in rdf

app/models/synapse.rb

@@ -57,7 +57,7 @@ class Synapse < ApplicationRecord
     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)
+    output += %(  rdfs:comment "#{desc}" ;\n) if desc.present?
     output[-2] = '.'
     output += %(\n)
     output

app/models/topic.rb

@@ -85,9 +85,9 @@ class Topic < ApplicationRecord
   def as_rdf
     output = ''
     output += %(d:topic_#{id} a mm:topic ;\n)
-    output += %(  rdfs:label "#{name}";\n)
+    output += %(  rdfs:label "#{name}" ;\n)
-    output += %(  rdfs:comment "#{desc}";\n)
+    output += %(  rdfs:comment "#{desc}" ;\n) if desc.present?
-    output += %(  foaf:homepage <#{link}>;\n) if link.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 .

app/models/user.rb

@@ -71,8 +71,8 @@ class User < ApplicationRecord
     base_url = opts[:base_url] || 'https://metamaps.cc'
     output = ''
     output += %(d:mapper_#{id} a foaf:OnlineAccount ;\n)
-    output += %(  foaf:accountName "#{name}";\n)
+    output += %(  foaf:accountName "#{name}" ;\n)
-    output += %(  foaf:accountServiceHomepage "#{base_url}/mapper/#{id}";\n)
+    output += %(  foaf:accountServiceHomepage "#{base_url}/mapper/#{id}" ;\n)
     output[-2] = '.' # change last ; to a .
     output += %(\n)
     output