Skip to main content

Wanelo Blog Post: Detangling Business Logic in Rails Apps with PORO Events and Observers

I recently wrote a blog post about how Wanelo uses events and observers in plain ruby, to model application events. The base code that supports it is available in the open sourced gem ventable.

If you want your business logic "glue" to look like this below, read the above blog post.
Wanelo::Event::ProductSave.configure do
  notifies Product,
           SaveNotification,
           SaveAction,
           inside: :transaction

  notifies ProductSaveWorker,
           ResaveEmailWorker
end
We have found so many applications of using events in the backend Rails application, that I can not imagine building another app without it.

Having said that, right now Ventable does not support distributed events. But it absolutely could! I am considering writing a plugin for sidekiq background processing framework, that could notify any observer via a background job, and not inside the current ruby thread.    Another option is to use another thread! Lots of options for concurrency.

Perhaps one day, it will look like this:
Wanelo::Event::ProductSave.configure do
  notifies Product,
           SaveNotification,
           SaveAction,
           inside: :transaction

  notifies PostSaveProcessor, via: :worker
  notifies ResaveEmailWorker, via: :thread
end

Comments

Popular posts from this blog

Car or Auto Make-Model-Year Database : For Breakfast

Make Model What? If you like me were tasked with loading a database of recent car makes/models/years, you would start by looking on the web and seeing if someone else just has it out there, readily available, hopefully for free, but perhaps for a tiny nominal fee.? If only it was that simple... I looked and looked, and couldn't find anything that would fit the above requirements. So I thought, who would know about US car models better than Kelly Blue Book? So I went on their site, and sure enough they have a javascript file that lists all known to them makes and models of used cars. Since the file is public, I figured it's not really "evil" if I scrape and parse it for my own benefit. Disagree? Have a better source? Then leave a comment. Anyway, to cut the long story short, I'm hoping to save a day or so to someone else who may, like me, be looking for this information. The ruby module shown below retrieves and parses the javascript from KBB site into

On Ruby on Rails with PostgreSQL, and Acts as Paranoid

Back a few years ago I was researching differences between PostgreSQL and MySQL databases, and chose PostgreSQL because at the time it supported foreign key constraints and many other fantastic SQL extensions that make developer's life a lot easier. Today I am sure MySQL is just as functional as PostgreSQL, and it does appear to be a more popular choice as the Rails DB than MySQL. I still prefer PostgreSQL, it just feels more natural to me coming out of Oracle background, so I am probably biased (who isn't?) Anyway, in the last year and a half or so, I've been writing Rails apps that use PG-based databases and found a few random tricks I'd love to share here. Opinions differ here, but just like accountants like the ancient double entry accounting system, I personally prefer a double validation system - where Rails validates my objects before/after updates, but the database double checks this using proper constraints. Rail's validation system is very robust and exte

Getting RMagic and friends to work on OS-X Mountain Lion

Upgraded my ruby environment today to Mountain Lion. Here is a quick checklist that I went through to get everything working.  The largest change was having to reinstall XCode and command line tools, and also download XQuarts in order to reinstall ImageMagick successfully. Without it, I was getting errors building RMagick of the following shape: ld: file not found: /usr/lib/libltdl.7.dylib for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation) make: *** [RMagick2.bundle] Error 1 Quick checklist: Install Mountain Lion Install XCode 4.4 Install command line tools from XCode 4.4 Preferences dialog Install XQuartz In terminal run brew update brew uninstall imagemagick brew install --fresh imagemagick wipe out your ~/.rvm folder reinstall RVM and install the latest ruby 1.9.3-p-194 run "bundle" in the project folder run "rake" and rejoice References: https://github.com/mroth/lolcommits/issu