lib/active_metadata/base.rb in active_metadata-0.2.2 vs lib/active_metadata/base.rb in active_metadata-0.2.3

@@ -1,15 +1,16 @@
 module ActiveMetadata
 
   CONFIG = File.exists?('config/active_metadata.yml') ? YAML.load_file('config/active_metadata.yml')[Rails.env] : {}
   CONFIG['cache_expires_in'] ||= 60
-  
+
   ## Define ModelMethods
   module Base
-    
+
     require 'paperclip'
     require "active_metadata/persistence/persistence"
+    require "active_metadata/helpers"
 
     def self.included(klass)
       klass.class_eval do
         extend Config
       end
@@ -17,28 +18,30 @@
 
     module Config
 
       def acts_as_metadata *args
         after_save :save_history
-        
+
         class_variable_set("@@metadata_id_from", args.empty? ? nil : args[0][:metadata_id_from])
 
         include ActiveMetadata::Base::InstanceMethods
-        include ActiveMetadata::Persistence   
-             
+        include ActiveMetadata::Persistence
+
       end
 
     end
 
     module InstanceMethods
-      
+
+      include ActiveMetadata::Helpers
+
       def self.included(klass)
-        [:notes,:attachments,:history].each do |item|
-          klass.send(:define_method,"#{item.to_s}_cache_key".to_sym) do |field|
-            "#{Rails.env}/active_metadata/#{item.to_s}/#{self.class}/#{metadata_id}/#{field}/"            
-          end  
-        end          
+        [:notes, :attachments, :history].each do |item|
+          klass.send(:define_method, "#{item.to_s}_cache_key".to_sym) do |field|
+            "#{Rails.env}/active_metadata/#{item.to_s}/#{self.class}/#{metadata_id}/#{field}/"
+          end
+        end
       end
 
       def metadata_id
         metadata_id_from = self.class.class_variable_get("@@metadata_id_from")
         return self.id if metadata_id_from.nil?
@@ -46,19 +49,73 @@
         metadata_id_from.each do |item|
           receiver = receiver.send item
         end
         receiver.id
       end
-      
+
       def current_user_id
         if User.respond_to?(:current) && !User.current.nil?
-            User.current.id
+          User.current.id
         else
           nil
-        end      
-      end        
-                
+        end
+      end
+
+      # Resolve concurrency using the passed timestamps and the active_metadata histories
+      # To be called from controller before updating the model. Params that contains a conflict are removed from the params list.
+      # Returns 2 values containing the the deleted params with the related history:
+      # [{:key => [passed_value,history]}]
+      #
+      # first result is the WARNINGS array: conflict appears on a field not touched by the user that submit the value
+      # first result is the FATALS Array : if the conflict appears on a field modified by the user that submit the value
+      # an empty array is returned by default
+      def manage_concurrency(params, timestamp)
+        warnings = []
+        fatals = []
+
+        # scan params
+        params.each do |key, val|
+          # ensure the query order
+          histories = history_for key.to_sym, "created_at DESC"
+          latest_history = histories.first
+
+          # if form timestamp is subsequent the history last change go on
+          # if history does not exists yet go on
+          next if latest_history.nil? || timestamp > latest_history.created_at
+
+          #if the timestamp is previous of the last history change
+          if timestamp < latest_history.created_at
+            #remove the key from the update process
+            params.delete key
+
+            # We have a conflict.
+            # Check if the actual submission has been modified
+            histories.each do |h|
+              # Looking for the value that was loaded by the user. First history with a ts that is younger than the form ts
+              next if timestamp > h.created_at
+
+              # History stores values as strings so any boolean is stored as "0" or "1"
+              # We need to translate the params passed for a safer comparison.
+              if self.column_for_attribute(key).type == :boolean
+                b_val = to_bool(h.value)
+              end
+
+              if [h.value, b_val].include? val
+                warnings << {key => [val, h]}
+              else
+                fatals << {key => [val, h]}
+              end
+            end
+
+          end
+
+        end
+
+        return warnings, fatals
+      end
+
     end # InstanceMethods
+
   end
 
 end
 
 ::ActiveRecord::Base.send :include, ActiveMetadata::Base