BREdis

What is BREdis?

A Business Rule Engine that sits inside redis

How do I install it?

gem install bredis

or in your Gemfile

gem 'bredis'

Make sure your redis server is running! Redis configuration is outside the scope of this README, but check out the Redis documentation.

Usage

require 'bredis'

$redis = Redis.new(:db => 3)
product_discount_rules = Bredis::RuleSet.new($redis, 'product_discount_rules')
product_discount_rules << {
  'priority' => 1,
  'id' => 1,
  'op' => '?',
  'lhs' => {
    'id' => 2,
    'lhs' => '$product', 
    'op' => '==', 
    'rhs' => 'shoes'
  }, 
  'rhs' => {
    'id' => 3,
    'lhs' => '$discount', 
    'op' => '=',
    'rhs' => {
      'id' => 7,
      'lhs' =>'$fare',
      'op' => '/',
      'rhs' => 2}
  }
}

product_discount_rules << {
  'priority' => 2,
  'id' => 4,
  'op' => '?',
  'lhs' => {
    'id' => 5,
    'lhs' => '$product', 
    'op' => '==', 
    'rhs' => 'shoes'
  }, 
  'rhs' => {
    'id' => 6,
    'lhs' => '$discount', 
    'op' => '=',
    'rhs' => 200
  }
}

product_discount_rules.evaluate({'$product' => 'shoes', '$fare' => 1279.52})

Goals

• uses a pure JSON DSL
• is pretty damn fast (4000 conditions are evaluated in 8 msec and takes only approx 2.5 MB of RAM)
• allows you to search the rules
• can import/export to pure json (file I/O)
• can specify priorities for rules and evaluate the first N matching, based on priority
• has a nice UI (not this version)

Copyright

Copyright (c) 2012-2013 Schubert Cardozo. See LICENSE for further details.