Refactoring Artist model

lib/parsers/artist.rb

@@ -0,0 +1,49 @@
+# -*- encoding: utf-8 -*-
+
+module MusicBrainz
+  module Parsers
+    class Artist < Base
+      class << self
+        def model(xml)
+          res = {
+            :id => safe_get_attr(xml, "artist", "id"),
+            :type => safe_get_attr(xml, "artist", "type"),
+            :name => safe_get_value(xml, "artist > name").gsub(/[`’]/, "'"),
+            :country => safe_get_value(xml, "artist > country"),
+            :date_begin => safe_get_value(xml, "artist > life-span > begin"),
+            :date_end => safe_get_value(xml, "artist > life-span > end"),
+            :urls => {}
+          }
+          xml.css("relation-list[target-type='url'] > relation").each { |rel|
+            res[:urls][rel.attr("type").downcase.split(" ").join("_").to_sym] = rel.css("target").text
+          }
+          res
+        end
+
+        def search(xml)
+          artists = []
+          xml.css("artist-list > artist").each do |a|
+            artists << {
+              :name => a.first_element_child.text.gsub(/[`’]/, "'"),
+              :sort_name => self.safe_get_value(a, "sort-name").gsub(/[`’]/, "'"),
+              :weight => 0,
+              :desc => self.safe_get_value(a, "disambiguation"),
+              :type => self.safe_get_attr(a, nil, "type"),
+              :mbid => self.safe_get_attr(a, nil, "id"),
+              :aliases => a.css("alias-list > alias").map { |item| item.text }
+            }
+          end
+          artists
+        end
+
+        def release_groups(xml)
+          release_groups = []
+          xml.css("release-group").each do |rg|
+            release_groups << MusicBrainz::Parsers::ReleaseGroup.model(rg)
+          end
+          release_groups
+        end
+      end
+    end
+  end
+end

lib/parsers/base.rb

@@ -0,0 +1,30 @@
+# -*- encoding: utf-8 -*-
+module MusicBrainz
+  module Parsers
+    class << self
+      def get_by_name(name)
+        case name
+        when :artist_model
+          return { :const => MusicBrainz::Parsers::Artist, :method => :model }
+        when :artist_search
+          return { :const => MusicBrainz::Parsers::Artist, :method => :search }
+        when :artist_release_groups
+          return { :const => MusicBrainz::Parsers::Artist, :method => :release_groups }
+        end
+      end
+    end
+
+    class Base
+      class << self
+        def safe_get_attr(xml, path, name)
+          node = path.nil? ? xml : (xml.css(path).first unless xml.css(path).empty?)
+          node.attr(name) unless node.nil? or node.attr(name).nil?
+        end
+
+        def safe_get_value(xml, path)
+          xml.css(path).first.text unless xml.css(path).empty?
+        end
+      end
+    end
+  end
+end

lib/parsers/release_group.rb

@@ -0,0 +1,19 @@
+# -*- encoding: utf-8 -*-
+
+module MusicBrainz
+  module Parsers
+    class ReleaseGroup < Base
+      class << self
+        def model(xml)
+          {
+            :id => safe_get_attr(xml, nil, "id"),
+            :type => safe_get_attr(xml, nil, "type"),
+            :title => safe_get_value(xml, "title"),
+            :disambiguation => safe_get_value(xml, "disambiguation"),
+            :first_release_date => safe_get_value(xml, "first-release-date")
+          }
+        end
+      end
+    end
+  end
+end