Add ability to set an error handler

README.md

@@ -29,6 +29,27 @@ You could configure TireAsyncIndex in initializer:
         config.use_queue         :high    # name of your queue
     end
 
+### Error Handling
+
+You can specify an error handling class:
+
+    TireAsyncIndex.configure do |config|
+      config.error_handler TireAsyncHandler
+    end
+
+It must respond to `handle`, for instance if you want to retry on a term
+exception and you use Resque:
+
+    class TireAsyncHandler
+      def self.handle(klass, action_type, class_name, id, exception)
+        if exception.is_a?(Resque::TermException)
+          Resque.enqueue(klass, action_type, class_name, id)
+        else
+          raise exception
+        end
+      end
+    end
+
 ## Usage
 
 Just add AsyncCallbacks to your model:

lib/tire_async_index.rb

@@ -19,6 +19,10 @@ def engine
     self.configuration.engine
   end
 
+  def error_handler
+    self.configuration.error_handler
+  end
+
   def worker
     case configuration.engine
     when :sidekiq

lib/tire_async_index/configuration.rb

@@ -4,6 +4,7 @@ class Configuration
 
     attr_accessor :queue
     attr_accessor :engine
+    attr_accessor :error_handler
 
     def background_engine type
       if AVALAIBLE_ENGINE.include?(type.to_sym)
@@ -17,10 +18,14 @@ def use_queue name
       @queue = name.to_sym
     end
 
+    def use_error_handler error_handler
+      @error_handler = error_handler
+    end
+
     def initialize
       @queue  = :normal
       @engine = :none
     end
 
   end
-end
+end

lib/tire_async_index/workers/resque.rb

@@ -1,6 +1,7 @@
 module TireAsyncIndex
   module Workers
     class Resque < UpdateIndex
+
       def self.queue; TireAsyncIndex.queue end
 
       def self.run(action_type, class_name, id)
@@ -9,6 +10,12 @@ def self.run(action_type, class_name, id)
 
       def self.perform(action_type, class_name, id)
         self.new.process(action_type, class_name, id)
+      rescue Exception => e
+        if TireAsyncIndex.error_handler
+          TireAsyncIndex.error_handler.handle(self, action_type, class_name, id, e)
+        else
+          raise e
+        end
       end
     end
   end

lib/tire_async_index/workers/sidekiq.rb

@@ -11,6 +11,12 @@ def self.run(action_type, class_name, id)
 
       def perform(action_type, class_name, id)
         process(action_type, class_name, id)
+      rescue Exception => e
+        if TireAsyncIndex.error_handler
+          TireAsyncIndex.error_handler.handle(self, action_type, class_name, id, e)
+        else
+          raise e
+        end
       end
 
     end

spec/active_record_tire_async_index_spec.rb

@@ -59,6 +59,14 @@ def async_tire_object_id
         end
       }.to raise_error(TireAsyncIndex::EngineNotFound)
     end
+
+    it "should be able to set a class as an error handler" do
+      TireAsyncIndex.configure do |config|
+        config.use_error_handler Object
+      end
+
+      TireAsyncIndex.error_handler.should eql Object
+    end
   end
 
   context "integration" do
@@ -158,3 +166,4 @@ def async_tire_object_id
 
   end
 end
+