mexxik / rpc-amqp

node.js library for cross-application communication via amqp

rpc-amqp

node.js library for cross-application communication via amqp.

#Setup

Install the dependency:

npm install rpc-amqp

Require it in your application:

var RPC = require('rpc-amqp');

#Usage

To make the library working you need to have a default installation of RabbitMQ message broker: https://www.rabbitmq.com/download.html

##Client

Create a client object to send and receive RPCs (multiple objects could be created within the same scope):

var client = RPC.create();

##Connection

You can establish a connection to a default localhost with guest:guest credentials:

client.connect();

Or customize your connection with parameters:

client.connect({
    host: 'localhost',
    port: 5672,
    username: 'guest',
    password: 'guest'
});

##Ready

When the library connects to the broker and makes all preparations it emits ready event. At this point you can start registering callbacks and send RPCs:

client.on('ready', function() {
    // messages sending and callbacks registration here
});

##Workflow

The workflow consists of sending, receiving and returning the result:

• to send a call you invoke call method on your client.
• to receive a call you implement a callback function with client's register.
• to return a result you pass a result object to callback function in register.

###client.call(name[,params][,options][,callback])

Makes a call with specified params and options. If there is a callback registered in the system the callback with a result will be returned.

• name: name of the call that should be invoked remotely.
• params: parameters of the call that will be passed to the remote consumer.
• options: options that define the behaviour (like roles and routes) of the call. Allow to customize the call and
• callback: callback function that will be invoked when the remote consumer replies with a result.

Here is an example of client.call usage:

sender.call('getRandomNumber', {}, {}, function(result){
    console.log(result);
});

###client.register(name[, callback])

Registers an RPC by a specified name. You can return a result object to the sender by calling callback.

• name: name of the call that the client should reply to.
• callback: function that could be called in if you want to reply with a result.

Here is an example of client.register that can listen to the call sent in the previous example (getRandomNumber):

client.register('getRandomNumber', function (params, response) {
    var number = Math.random();

    response(number);
});

#Routing

##Path

##ID

##Roles

#Examples

01 Basic - Random Number

02 Roles - Multiple Servers