Optional execution on precompile

README.md

@@ -306,21 +306,33 @@ With the new **user_env_compile** feature of Heroku (see above), this is no long
 
 ## Rake Task
 
-A rake task is included within the **asset_sync** gem to enhance the rails precompile task by automatically running after it.
+A rake task is included within the **asset_sync** gem to perform the sync:
+
+``` ruby
+  namespace :assets do
+    desc "Synchronize assets to S3"
+    task :sync => :environment do
+      AssetSync.sync
+    end
+  end
+```
+
+If `AssetSync.config.run_on_precompile` is `true` (default), then assets will be uploaded to S3 automatically after the `assets:precompile` rake task is invoked:
 
 ``` ruby
-  # asset_sync/lib/tasks/asset_sync.rake
   if Rake::Task.task_defined?("assets:precompile:nondigest")
     Rake::Task["assets:precompile:nondigest"].enhance do
-      AssetSync.sync
+      Rake::Task["assets:sync"].invoke if defined?(AssetSync) && AssetSync.config.run_on_precompile
     end
   else
     Rake::Task["assets:precompile"].enhance do
-      AssetSync.sync
+      Rake::Task["assets:sync"].invoke if defined?(AssetSync) && AssetSync.config.run_on_precompile
     end
   end
 ```
 
+You can disable this behavior by setting `AssetSync.config.run_on_precompile = false`.
+
 ## Sinatra/Rack Support
 
 You can use the gem with any Rack application, but you must specify two

lib/asset_sync/config.rb

@@ -14,6 +14,7 @@ class Invalid < StandardError; end
     attr_accessor :prefix
     attr_accessor :public_path
     attr_accessor :enabled
+    attr_accessor :run_on_precompile
 
     # FOG configuration
     attr_accessor :fog_provider          # Currently Supported ['AWS', 'Rackspace']
@@ -50,6 +51,7 @@ def initialize
       self.always_upload = []
       self.ignored_files = []
       self.enabled = true
+      self.run_on_precompile = true
       load_yml! if defined?(Rails) && yml_exists?
     end
 
@@ -126,6 +128,7 @@ def load_yml!
       self.fail_silently          = yml["fail_silently"] if yml.has_key?("fail_silently")
       self.always_upload          = yml["always_upload"] if yml.has_key?("always_upload")
       self.ignored_files          = yml["ignored_files"] if yml.has_key?("ignored_files")
+      self.run_on_precompile      = yml["run_on_precompile"] if yml.has_key?("run_on_precompile")
 
       # TODO deprecate the other old style config settings. FML.
       self.aws_access_key_id      = yml["aws_access_key"] if yml.has_key?("aws_access_key")

lib/tasks/asset_sync.rake

@@ -1,13 +1,22 @@
+namespace :assets do
+  desc "Synchronize assets to S3"
+  task :sync => :environment do
+    AssetSync.sync
+  end
+end
+
 if Rake::Task.task_defined?("assets:precompile:nondigest")
   Rake::Task["assets:precompile:nondigest"].enhance do
-    AssetSync.sync
+    # Conditional execution needs to be inside the enhance block because the enhance block
+    # will get executed before yaml or Rails initializers.
+    Rake::Task["assets:sync"].invoke if defined?(AssetSync) && AssetSync.config.run_on_precompile
   end
 else
   Rake::Task["assets:precompile"].enhance do
     # rails 3.1.1 will clear out Rails.application.config if the env vars
     # RAILS_GROUP and RAILS_ENV are not defined. We need to reload the
     # assets environment in this case.
     # Rake::Task["assets:environment"].invoke if Rake::Task.task_defined?("assets:environment")
-    AssetSync.sync
+    Rake::Task["assets:sync"].invoke if defined?(AssetSync) && AssetSync.config.run_on_precompile
   end
 end

spec/asset_sync_spec.rb

@@ -16,6 +16,10 @@
       end
     end
 
+    it "should default to running on precompile" do
+      AssetSync.config.run_on_precompile.should be_true
+    end
+
     it "should default AssetSync to enabled" do
       AssetSync.config.enabled?.should be_true
       AssetSync.enabled?.should be_true
@@ -70,6 +74,10 @@
       AssetSync.enabled?.should be_true
     end
 
+    it "should configure run_on_precompile" do
+      AssetSync.config.run_on_precompile.should be_false
+    end
+
     it "should configure aws_access_key_id" do
       AssetSync.config.aws_access_key_id.should == "xxxx"
     end

spec/aws_with_yml/config/asset_sync.yml

@@ -3,6 +3,7 @@ defaults: &defaults
   aws_access_key_id: "xxxx"
   aws_secret_access_key: "zzzz"
   region: "eu-west-1"
+  run_on_precompile: false
 
 development:
   <<: *defaults