# Sandthorn Event Sourcing
A ruby framwork for saving an object's state as a series of events, and tracking non state changing events.

## What is Event Sourcing

"Capture all changes to an application state as a sequence of events."
[Event Sourcing](http://martinfowler.com/eaaDev/EventSourcing.html)

## The short story

Think of it as an object database where you not only what the new value of the attribute is but when and why it changed.
_Example:_

```ruby

#Setup the Aggregate

require 'sandthorn/aggregate_root_dirty_hashy' #the one available right now

class Ship
  include Sandthorn::AggregateRoot::DirtyHashy 
	attr_reader :name

	def initialize name: nil, shipping_company: nil
		@name = name
	end

	# state-changing command
	def rename! new_name: ""
		unless new_name.empty? or new_name == name
			@name = new_name
			ship_was_renamed
		end
	end
	private
	# commit the event and state-change is automatically recorded.
	def ship_was_renamed
		commit
	end
end

#Setup the framework with the sequel driver for persistance
url = "path to sql" #Example sqlite://path/sequel_driver.sqlite3 
catch_all_config = [ { driver: SandthornDriverSequel.driver_from_url(url: url) } ]
Sandthorn.configuration = catch_all_config

#migrate db schema for the sequel driver
migrator = SandthornDriverSequel::Migration.new url: url
SandthornDriverSequel.migrate_db url: url

#Usage
ship = Ship.new "Titanic"
ship.rename! "Vasa"
puts ship.aggregate_events
ship.save

new_ship = Ship.find ship.id
puts ship.name
.
.

For more info look at the specs.

```

## Installation

Add this line to your application's Gemfile:

    gem 'sandthorn'

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install sandthorn

## Usage

TODO: Write usage instructions here

## Contributing

1. Fork it
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Add some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create new Pull Request