sparqling soprano via dbus and ruby

gistfile1.rbx

=begin
     nepomukserver --nofork

And then:

    kcmshell4 kcm_nepouk

to set what files to scan.

If the environment variable DBUS_SESSION_BUS_ADDRESS is not set then you
need to put this in your .xinitrc:

    eval `dbus-launch --sh-syntax --exit-with-session`
=end

require 'dbus'

class SopranoClient
  def initialize
    @bus = DBus::SessionBus.instance

    proxy = @bus.introspect("org.kde.NepomukStorage", "/org/soprano/Server")
    model_s = proxy["org.soprano.Server"].createModel("main")[0]

    @model = @bus.introspect('org.kde.NepomukStorage', model_s)
  end

  def each_result(sparql)
    xyz_s = @model['org.soprano.Model'].executeQuery(sparql, 'SPARQL')[0]

    xyz = @bus.introspect('org.kde.NepomukStorage', xyz_s)

    while xyz['org.soprano.QueryResultIterator'].next[0]
      line = xyz['org.soprano.QueryResultIterator'].current[0][0]
      yield line
    end
  end
end

sparql = <<END
PREFIX xes: <http://freedesktop.org/standards/xesam/1.0/core#>

SELECT ?type ?path ?name ?size
WHERE {
  ?x xes:mimeType ?type .
  ?x xes:url ?path .
  ?x xes:name ?name .
  ?x xes:size ?size .
  FILTER ( regex(?type, 'image/') )
}
END

cl = SopranoClient.new

cl.each_result(sparql) do |line|
  type = line['type'][1]
  path = line['path'][1]
  name = line['name'][1]
  size = line['size'][1]

  puts [type, path, name, size].inspect
end