Save Queue

Save Queue allows to push related objects to an object's queue for delayed save, that will triggered on object#save. In this case object wil store all related information on its save.

Installation

gem install save_queue

Usage

How to start:

1. include SaveQueue:

   require 'save_queue'
   class Artice
     include SaveQueue
   end
   

2. call #mark_as_saved method when object gets dirty:

   class Artice
     def change_attribute attr, value
       @attributes[attr] = value
       mark_as_saved # call this and object will be marked for save
     end
   end
   

3. point save method to your save logic or dont care if you use #save already:

   class Artice
     # @return [boolean]
     def save
       write
     end
   end
   

4. If you want to use validation, include SaveQueue::Plugins::Validation and implement #valid? method. You may got failed objects by save_queue.objects_with_errors

   class Artice
     include SaveQueue::Plugins::Validation
   
     # @return [boolean]
     def valid?
       true
     end
   end
   

5. add SaveQueue to some other classes:

   require 'save_queue'
   class Tag
     include SaveQueue
   end
   
   class Artice
     def tags= tag_objects
       @tags = tag_objects
       saved_queue.add_all tag_objects
     end
   
     def add_tag tag
       @tags ||= []
       @tags << tag
       saved_queue.add tag
     end
   end
   

6. Use it:

   article = Article.new
   tag_objects = [Tag.new, Tag.new, Tag.new]
   article.tags = tag_object
   article.add_tag Tag.new
   
   # that will save article and all tags in this article if article
   # and tags are valid, and if article.save and all tag.save returns true
   article.save
   

7. Handle errors

7.1. You did not include SaveQueue::Plugins::Validation:

    begin
      article.save
    rescue SaveQueue::FailedSaveError => save_error

      # @params [Hash] info
      # @option info [Array<Object>] :saved
      # @option info [Object]        :failed
      # @option info [Array<Object>] :pending
      save_error.context
    end

7.2. You've included SaveQueue::Plugins::Validation:

    # Note nothing was actually saved. You dont need to do a cleanup
    unless article.save then
      failed_objects = article.saved_query.objects_with_errors
    end

If you have custom logic for marking objects dirty then you may want to override #has_unsaved_changes? method in you class like this:

def has_unsaved_changes?
  dirty? # dirty is you custom method to determine has object unsaved_changes or not
end

method #mark_as_saved becomes useless in this case and you should mark objects by your self.

Note: Today Save Queue use only #save method to perform save actions on an objects, but later this should be changed to custom option.

Requirements

ActiveSupport rspec2 for testing

Compatibility

tested with Ruby

• 1.8.7
• 1.9.2
• 1.9.3
• jruby
• ruby-head
• ree

see build history

Copyright

Copyright © 2011 Alexander N Paramonov. See LICENSE for details.