Autodeps

TODO: Write a gem description

Installation

Add this line to your application's Gemfile:

gem 'autodeps'

And then execute:

$ bundle

Or install it yourself as:

$ gem install autodeps

Usage

TODO: Write usage instructions here two parts 1.ReactivePersistency 2.ReactiveData

ReactivePersistency is used in data storage layer, like you have an activerecord/mongomapper persistency layer, when some properties you want to copy to other table(denormalization), and want to be automatically synced when main table's property changes, then just include Autodeps::Persistency and call depend_on method: like you have User table, and Laud table, where you copy user.name to Laud.user_name and Laud.dest_user_name

class Laud

  include MongoMapper::Document
  include Autodeps::Persistency #这里添加对Autodeps::Persistency 的依赖

  key :user_id, Integer, :required => true
  key :user_name, String
  depend_on "User", :value_mapping => {:name => :user_name} #默认可以省略 :key_mapping=> {:id=>:user_id}

  key :dest_user_id, Integer, :required => true
  key :dest_user_name, String
  depend_on "User", :key_mapping => {:id => :dest_user_id}, :value_mapping => {:name => :dest_user_name}

  timestamps!

  ensure_index([[:user_id,1],[:dest_user_id,1]])
end

then when you change user's name

user.name = "some value"
user.save

the name change will automatically propagated to Laud table/collection.

because in development environment, when User loads, the Laud class may not been loaded, so you may want to do this:

user.rb

class User #some attributes end Laud #just adds a reference here to cause rails to load Laud

2.ReactiveData what ReactiveData means, if you want to say a=b+c if b or c is ReactiveData, then when b or c's value changes, a's value automatically changes,it's the concept copyed from meteor:)

see autodeps_test.rb where a,b is ReactiveData

def test_reactive_integer a = Autodeps::ReactiveData.new(3) b = nil computation = Autodeps.autorun do |computation| #the block will be rerun if a changes b = a.value end assert_equal b,3

a.change_to 5

assert_equal b,5

end

def test_reactive_integer_add a = Autodeps::ReactiveData.new(3) b = Autodeps::ReactiveData.new(5) c = nil computation = Autodeps.autorun do |computation| #the block will be rerun if a or b changes c = a.value + b.value end assert_equal c,8

a.change_to 5

assert_equal c,10

b.change_to 15

assert_equal c,20

end

Contributing

1. Fork it ( http://github.com//autodeps/fork )
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