Adding institution importer

app/services/institution_importer.rb

+class InstitutionImporter
+
+  attr_accessor :items
+
+  def initialize
+    @names = []
+    @learning_objects = []
+  end
+
+  def import
+    @items.each do |learning_object|
+      publisher = learning_object.get_metadata_value_of 'dc.creator'
+      if publisher.nil?
+        institution = Institution.where(name: "Banco Internacional de Objetos Educacionais").first_or_create
+      elsif !institution_exists?(publisher)
+        institution = Institution.new(name: publisher)
+        institution.save
+        @names << publisher
+      end
+
+      learning_object.publisher = institution
+      learning_object.save
+    end
+  end
+
+  private
+
+  def institution_exists?(publisher)
+    exists = @names.include? publisher
+    unless exists
+      exists = Institution.exists?(name: publisher)
+      @names << publisher if exists
+    end
+    exists
+  end
+end

lib/tasks/import.rake

@@ -45,6 +45,49 @@ namespace :import do
     logger.close
   end
 
+  task :institution, [:log] => [:environment] do |t, args|
+    desc "Create Publisher relations based on its metadata"
+    include Log::Logging
+
+    args.with_defaults(:log => STDOUT)
+
+    Log::Logging.logger = Log::DatabaseLogger.new(args.log)
+    logger.level = Log::DatabaseLogger::CREATE
+
+
+    # Quantity of items fetched on each iteration
+    limit = 500
+    # Start point from where items will be fetched
+    offset = 0
+    importer = InstitutionImporter.new
+
+    loop do
+      logger.info " --> Creating Publisher relations from #{offset} to #{offset+limit}"
+
+      begin
+        # Get learning_objects (from offset to offset+limit)
+        learning_objects = LearningObject.limit(limit).offset(offset)
+
+      rescue => e
+        logger.warn "Database error, going to sleep"
+        logger.error e
+        # Sleeps for a while to wait database's recovery
+        sleep(10.seconds)
+        # Goes to next iteration to retry
+        next
+      else
+        # Terminate loop if there are no more learning_objects to import
+        break if learning_objects.empty?
+
+        importer.items = learning_objects
+        importer.import
+
+      end
+      offset += limit
+    end
+    logger.close
+  end
+
   task :learning_objects, [:log] => [:environment] do |t, args|
     desc "Importing Learning Objects from Dspace items"