## Using Untied with Goliath

This example defines both the Producer and the Consumer. The producer is defined inside srv.rb, which is a goliath server. The consumer doesn't depend on the producer in any way.

### Setup

```sh
$ > git clone git://github.com/redu/untied.git
$ > cd untied/examples/goliath
$ > bundle install
```

The Untied gem relies on RabbitMQ, so it need to be installed in order to work properly. [Here are](http://www.rabbitmq.com/download.html) the instructions.

### Structure

```sh
.
├── Gemfile
├── Gemfile.lock
├── README.mkd
├── Rakefile # Requires the observer.rb. Listens on the message bus.
├── config
│   └── srv.rb # ActiveRecord and Untied Publisher configurations
├── models
│   └── user.rb # ActiveRecord User model
├── observer.rb # Untied observer used by consumer
└── srv.rb # Goliath server and Untied::Doorkeeper
```

### More info

If you don't know what some of the components above means, here are some references:

- [Untied::Observer](https://github.com/redu/untied#consumer)
- [Untied publisher configurations](https://github.com/redu/untied#publisher)
- [Goliath](http://postrank-labs.github.com/goliath/)
- [Goliath configurarions](https://github.com/postrank-labs/goliath/wiki/Configuration)

### Usage

#### Publisher

The publisher consists of a REST API defined as a Goliath server. Every time an User is created using this API the Untied publisher will serialize it and deliver it through the message bus.

All you need is to initialize goliath server

```sh
goliath (master) > ruby srv.rb -sv
I, [2012-10-18T10:06:50.806799 #9274]  INFO -- : Untied: Initializing publisher observer
[9274:INFO] 2012-10-18 10:06:50 :: Starting server on 0.0.0.0:9000 in development mode. Watch out for stones.
-- create_table(:users, {:force=>true})
   -> 0.0158s
```

And use the REST API:

```sh
goliath (master) > curl http://0.0.0.0:9000?name=guila -X POST
"{\"user\":{\"created_at\":\"2012-10-18T09:59:14-03:00\",\"id\":1,\"name\":\"guila\",\"updated_at\":\"2012-10-18T09:59:14-03:00\"}}"
```

#### Consumer

The consumer listens to the events sent to the message bus and fires defined Untied::Observer methods. In this example we just defined an ``after_create`` method for the User entity (see observer.rb).

To initialize the cosumer call the following rake task:

```sh
goliath (master) > rake untied:consumer:work
I, [2012-10-18T10:09:44.687311 #9327]  INFO -- : Worker initialized and listening
```

Everytime an user is created on the publisher side, the consumer will process the event and call the proper callback (defined in observer.rb):

```
#   I, [2012-10-18T09:59:14.927815 #9133]  INFO -- : Untied::Consumer: processing event after_create from goliath with payload {:user=>{:created_at=>"2012-10-18T09:59:14-03:00", :id=>1, :name=>"guila", :updated_at=>"2012-10-18T09:59:14-03:00"}}
#   An user was created on Goliath server, yay!
```

Of course you should consume events produced by other server, say a Rails server.