Better parsing of thumbnail options

Author: Bart Zonneveld

app/controllers/api/presets_controller.rb

@@ -98,11 +98,12 @@ def update
     if params[:preset]
       params[:name] = params[:preset][:name]
       params[:parameters] = params[:preset][:parameters]
+      params[:thumbnail_options] = params[:preset][:thumbnail_options]
     end
 
     preset = Preset.find(params[:id])
 
-    if preset.update_attributes(:name => params[:name], :parameters => params[:parameters])
+    if preset.update_attributes(:name => params[:name], :parameters => params[:parameters], :thumbnail_options => params[:thumbnail_options])
       respond_with preset, :location => api_preset_url(preset) do |format|
         format.html { redirect_to presets_path }
       end

app/models/preset.rb

@@ -3,11 +3,24 @@ class Preset < ActiveRecord::Base
 
   validates :name, :parameters, :presence => true
   validates :name, :uniqueness => true
+
+  validate :thumbnail_options, :valid_json_options, :if => Proc.new { |p| p.thumbnail_options.present? }
 
   def self.from_api(attributes)
     attributes = attributes[:preset] if attributes[:preset]
     create(:name => attributes['name'], 
            :parameters => attributes['parameters'],
            :thumbnail_options => attributes['thumbnail_options'])
   end
+
+  private
+    def valid_json_options
+      begin
+        JSON.parse(self.thumbnail_options)
+        true
+      rescue JSON::ParserError
+        errors.add(:thumbnail_options, "must be valid JSON")
+        false
+      end
+    end
 end

app/models/transcoder.rb

@@ -12,11 +12,17 @@ def schedule(opts)
     end
 
     def job_to_json(job)
+      if job.preset.thumbnail_options.present?
+        thumb_opts = JSON.parse(job.preset.thumbnail_options)
+      else
+        thumb_opts = nil
+      end
+
       {
         'source_file' => job.source_file,
         'destination_file' => job.destination_file,
         'encoder_options' => job.preset.parameters,
-        'thumbnail_options' => job.preset.thumbnail_options,
+        'thumbnail_options' => thumb_opts,
         'callback_urls' => [ job.callback_url ]
       }.to_json
     end
@@ -38,16 +44,25 @@ def post(url, *attrs)
     def get(url, *attrs)
       call_transcoder(:get, url, *attrs)
     end
+
+    def log(str)
+      logger.info "#{Time.now} - #{str}"
+    end
 
     private
       def call_transcoder(method, url, *attrs)
         begin
+          log "Calling #{url} with #{attrs}"
           attrs << { :content_type => :json, :accept => :json, :timeout => 2 }
           response = RestClient.send(method, url, *attrs)
           JSON::parse response
         rescue Errno::ECONNREFUSED, SocketError, Errno::ENETUNREACH, Errno::EHOSTUNREACH, RestClient::Exception, JSON::ParserError
           false
         end
       end
+
+      def logger
+        @_logger = ActiveSupport::BufferedLogger.new(Rails.root.join('log/transcoder.log'))
+      end
   end
 end

spec/factories.rb

@@ -10,7 +10,7 @@
   factory :preset do |p|
     p.name 'h264'
     p.parameters 'params'
-    p.thumbnail_options 'thumbs'
+    p.thumbnail_options '{"seconds":1}'
   end
 
   factory :host do |h|

spec/models/transcoder_spec.rb

@@ -40,7 +40,7 @@ def do_schedule
         'source_file' => 'source',
         'destination_file' => 'dest',
         'encoder_options' => 'params',
-        'thumbnail_options' => 'thumbs',
+        'thumbnail_options' => {seconds: 1},
         'callback_urls' => ["callback_url"]
       }.to_json
     end