Query wikidata using ruby

twitter_from_orcid.rb

# Install via command-line as 'gem install sparql-client'
require 'sparql/client'

headers = { 'User-Agent' => 'Ruby-Sparql-Client/1.0' }
@sparql = SPARQL::Client.new("https://query.wikidata.org/sparql", headers: headers, read_timeout: 120)

# A SPARQL query to find an item and an optional Twitter handle
def wikidata_by_orcid_query(orcid)
  %Q(
    SELECT ?item ?itemLabel ?twitter
    WHERE {
      VALUES ?orcid {"#{orcid}"} {
        ?item wdt:P496 ?orcid .
      }
      OPTIONAL {
        ?item wdt:P2002 ?twitter .
      }
      SERVICE wikibase:label {
        bd:serviceParam wikibase:language "en" .
      }
    }
  )
end

def twitter_from_orcid(orcid)
  @sparql.query(wikidata_by_orcid_query(orcid)).each_solution do |solution|
    return "@#{solution.to_h[:twitter]}" if solution
  end
  nil
end

# Let's try Roderic Page, https://orcid.org/0000-0002-7101-9767
puts twitter_from_orcid("0000-0002-7101-9767")