implemented a basic validator module for lastfm results (improvement necessary)

Gemfile

@@ -1,5 +1,7 @@
 source 'http://rubygems.org'
 
+gem 'rake', '!= 0.9.0'
+
 gem 'rails', '3.0.5'
 gem 'jquery-rails', '>= 0.2.6'
 

Gemfile.lock

@@ -43,7 +43,7 @@ GEM
     httparty (0.7.7)
       crack (= 0.1.8)
     i18n (0.6.0)
-    jquery-rails (1.0.7)
+    jquery-rails (1.0.9)
       railties (~> 3.0)
       thor (~> 0.14)
     json (1.5.1)
@@ -73,7 +73,7 @@ GEM
       activesupport (= 3.0.5)
       rake (>= 0.8.7)
       thor (~> 0.14.4)
-    rake (0.9.0)
+    rake (0.9.1)
     ruby_parser (2.0.6)
       sexp_processor (~> 3.0)
     sexp_processor (3.0.5)
@@ -88,7 +88,7 @@ GEM
       mime-types
       mime-types
     tzinfo (0.3.27)
-    youtube_it (1.4.2)
+    youtube_it (1.4.3)
       builder
       oauth (>= 0.4.4)
 
@@ -103,6 +103,7 @@ DEPENDENCIES
   jquery-rails (>= 0.2.6)
   json
   rails (= 3.0.5)
+  rake (!= 0.9.0)
   ruby_parser
   sqlite3
   sqlite3-ruby

app/controllers/artists_controller.rb

@@ -7,7 +7,7 @@ class ArtistsController < ApplicationController
     @tracks = LastFM::Artist.getTopTracks CGI.unescape(params[:id]), 10
     @albums = LastFM::Artist.getTopAlbums CGI.unescape(params[:id]), 8
     @images = LastFM::Artist.getImages CGI.unescape(params[:id]), 18
-    @related= LastFM::Artist.getSimilar CGI.unescape(params[:id]), 6
+    @related = LastFM::Artist.getSimilar CGI.unescape(params[:id]), 6
 
     LastFM::LastFMRequest.run_queue!
   end

app/helpers/application_helper.rb

@@ -5,7 +5,7 @@ module ApplicationHelper
     @attr = (type=="gallery") ? "name" : "size"
     image.each do |img|
       if img[@attr] == size.to_s
-        if img["#text"].empty?
+        if img["#text"].blank?
           return "/images/placeholder/#{type.to_s}.png"
         end
         return img["#text"]

app/views/artists/show.html.haml

@@ -28,8 +28,7 @@
             %ul.songs.long
               - @tracks.track.each do |track|
                 %li
-                  - id = @youtube_client.videos_by(:query => "#{track.name} #{track.artist.name} official", :page => 1, :per_page => 1, :order_by => "relevance")
-                  = image_tag "ico/play.png", :class=>"play", :videoid=>id.videos.first.unique_id
+                  = image_tag "ico/play.png", :class=>"play"
                   = image_tag "ico/add.png", :class=>"add"
                   %span= track.name
                   = link_to trimString(track.artist.name, 50), :controller=>"artists",:action=>"show",:id=>CGI.escape(track.artist.name)

lib/last_fm/album.rb

@@ -2,7 +2,11 @@ module LastFM
   
   class Album < LastFMRequest
     def self.search query, limit = nil, page = nil
-      album_request "search", "albummatches", query, nil, limit, page
+      album_request "search", "albummatches", query, nil, limit, page do |result|
+        result = LastFM::Validator.validate_mash result
+        result = Hashie::Mash.new({ :album => [] }) if result.blank?
+        update_results "#{current_class_name}_#{__method__}", result
+      end
     end
   
     # return: album name, artist, (top)tags, tracks ( name, duration (in sec) ) mbid (album), release date, image urls ( different sizes )

lib/last_fm/artist.rb

@@ -1,13 +1,20 @@
 module LastFM
   
   class Artist < LastFMRequest
+    
     def self.search query, limit = nil, page = nil
-      artist_request "search", "artistmatches", query, limit, page
+      artist_request "search", "artistmatches", query, limit, page do |result|
+        result = LastFM::Validator.validate_mash result
+        result = Hashie::Mash.new({ :artist => [] }) if result.blank?
+        update_results "#{current_class_name}_#{__method__}", result
+      end
     end
   
     # return: artist name, tags, similar artists, artist bio (summary / long), mbid, image urls ( different sizes )
     def self.getInfo artist
-      artist_request "getInfo", "artist", artist
+      artist_request "getInfo", "artist", artist do |info|
+        LastFM::Validator.validate_mash info, "tag", "image"
+      end
     end
   
     # return: artists ( name, mbid, image urls ( different sizes ) )
@@ -28,14 +35,18 @@ module LastFM
     # return: albums ( name, mbid, album url, image urls ( different sizes ) ) ordered by popularity
     def self.getTopAlbums artist, limit = nil, page = nil
       artist_request "getTopAlbums", "topalbums", artist, limit, page do |albums|
-        if albums["@attr"].total.to_i == 1
-          albums.album = [albums.album] # wrap with Array
-        end
+        albums = LastFM::Validator.validate_mash albums, "album"
+        albums = Hashie::Mash.new({ :album => [] }) if albums.total == "0"
+        update_results "#{current_class_name}_#{__method__}", albums
       end
     end
     
     def self.getImages artist, limit = nil
-      artist_request "getImages", "images", artist, limit
+      artist_request "getImages", "images", artist, limit do |images|
+        images = LastFM::Validator.validate_mash images, "image"
+        images = Hashie::Mash.new({ :image => [] }) if images.total == "0"
+        update_results "#{current_class_name}_#{__method__}", images
+      end
     end
   
   end

lib/last_fm/chart.rb

@@ -1,11 +1,18 @@
 module LastFM
+
   class Chart < LastFMRequest
     def self.getTopArtists limit = nil, page = nil
-      chart_request "getTopArtists", "artists", limit, page
+      chart_request "getTopArtists", "artists", limit, page do |artists|
+        LastFM::Validator.validate_mash artists, "image"
+        update_results "#{current_class_name}_#{__method__}", artists
+      end
     end
 
     def self.getTopTracks limit = nil, page = nil
-      chart_request "getTopTracks", "tracks", limit, page
+      chart_request "getTopTracks", "tracks", limit, page do |tracks|
+        LastFM::Validator.validate_mash tracks
+        update_results "#{current_class_name}_#{__method__}", tracks
+      end
     end
   end
 

lib/last_fm/last_fm_request.rb

@@ -34,52 +34,59 @@ module LastFM
     end
 
     def self.artist_request method, node, q, limit = nil, page = nil, &block
-      klass_name = self.name.split('::').last.downcase!
-      request_params = default_params.merge( :method => "#{klass_name}.#{method.to_s}", :artist => q, :limit => limit, :page => page )
-      create_and_queue_request klass_name, method, node, block, request_params
+      request_params = default_params.merge( :method => "#{current_class_name}.#{method.to_s}", :artist => q, :limit => limit, :page => page )
+      create_and_queue_request method, node, block, request_params
     end
 
     def self.album_request method, node, q, artist = nil, limit = nil, page = nil, &block
-      klass_name = self.name.split('::').last.downcase!
-      request_params = default_params.merge( :method => "#{klass_name}.#{method.to_s}", :album => q, :artist => artist, :limit => limit, :page => page )
-      create_and_queue_request klass_name, method, node, block, request_params
+      request_params = default_params.merge( :method => "#{current_class_name}.#{method.to_s}", :album => q, :artist => artist, :limit => limit, :page => page )
+      create_and_queue_request method, node, block, request_params
     end
 
     def self.track_request method, node, q, artist = nil, limit = nil, page = nil, &block
-      klass_name = self.name.split('::').last.downcase!
-      request_params = default_params.merge( :method => "#{klass_name}.#{method.to_s}", :track => q, :artist => artist, :limit => limit, :page => page )
-      create_and_queue_request klass_name, method, node, block, request_params
+      request_params = default_params.merge( :method => "#{current_class_name}.#{method.to_s}", :track => q, :artist => artist, :limit => limit, :page => page )
+      create_and_queue_request method, node, block, request_params
     end
 
     def self.chart_request method, node, limit = nil, page = nil, &block
-      klass_name = self.name.split('::').last.downcase!
-      request_params = default_params.merge( :method => "#{klass_name}.#{method.to_s}", :limit => limit, :page => page )
-      create_and_queue_request klass_name, method, node, block, request_params
+      request_params = default_params.merge( :method => "#{current_class_name}.#{method.to_s}", :limit => limit, :page => page )
+      create_and_queue_request method, node, block, request_params
+    end
+
+    protected
+
+    def self.update_results key, hash
+      @@results[(key.to_sym)].update hash
+    end
+
+    def self.current_class_name
+      self.name.split('::').last.downcase!
     end
 
     private
 
-    def self.create_and_queue_request klass_name, method, node, block, request_params
+    def self.create_and_queue_request method, node, block, request_params
       request = Typhoeus::Request.new(base_uri, :params => request_params)
-      handle_response request, klass_name, method, node, block
+      handle_response request, method, node, block
       
-      puts ">> ---- '#{klass_name}.#{method.to_s}' request is queued ----" if @@hydra.queue request
-      @@results[(klass_name + "_" + method).to_sym] = Hashie::Mash.new
+      puts ">> ---- '#{current_class_name}.#{method.to_s}' request is queued ----" if @@hydra.queue request
+      @@results[(current_class_name + "_" + method).to_sym] = Hashie::Mash.new
     end
 
-    def self.handle_response request, klass_name, method, node, block
+    def self.handle_response request, method, node, block
       request.on_complete do |response|
         if response.success?
-          puts "<< ---- '#{klass_name}.#{method.to_s}' -- TIME: #{response.time.to_s} ----"
+          puts "<< ---- '#{current_class_name}.#{method.to_s}' -- TIME: #{response.time.to_s} ----"
           
           hash = Hashie::Mash.new(JSON.parse(response.body))
+          puts hash
           hash = method.to_s == "search" ? hash.results.send(node.to_sym) : hash.send(node.to_sym)
           
-          @@results[(klass_name + "_" + method).to_sym].update hash
+          update_results "#{current_class_name}_#{method}", hash unless hash.blank?
           
-          block.call(@@results[(klass_name + "_" + method).to_sym]) unless block.nil?
+          block.call(@@results[("#{current_class_name}_#{method}").to_sym]) unless block.nil?
         elsif response.timed_out?
-          puts ">> -- '#{klass_name}.#{method.to_s}' -- TIMED OUT -- <<"
+          puts ">> -- '#{current_class_name}.#{method.to_s}' -- TIMED OUT -- <<"
         end
       end
     end

lib/last_fm/track.rb

@@ -2,7 +2,11 @@ module LastFM
   
   class Track < LastFMRequest
     def self.search query, limit = nil, page = nil
-      track_request "search", "trackmatches", query, nil, limit, page
+      track_request "search", "trackmatches", query, nil, limit, page do |result|
+        result = LastFM::Validator.validate_mash result
+        result = Hashie::Mash.new({ :track => [] }) if result.blank?
+        update_results "#{current_class_name}_#{__method__}", result
+      end
     end
   
     # return: track name, id, (top)tags, artist, duration (in msec), album ( artist, title, image urls ( different sizes) ), mbid

lib/last_fm/validator.rb

@@ -0,0 +1,28 @@
+module LastFM
+  
+  class Validator
+    
+    def self.validate_mash mash, *args
+      args.flatten!
+      
+      return [] if mash.blank?
+      
+      mash.each do |key, value|
+        if args.include? key.to_s || value.is_a?(Array)
+          mash[key] = Array.wrap value
+          mash[key].map do |mashie|
+            validate_mash mashie, args
+          end
+        elsif value.is_a? Hashie::Mash
+          mash[key] = validate_mash mash[key], args
+        end
+        mash[key] = "" if value.blank? && value.is_a?(String)
+        mash[key] = [] if value.blank? && value.is_a?(Array)
+      end
+      
+      return mash
+    end
+
+  end
+  
+end