evented-command

Introduction

Project goal is to provide a simple command/event handling for evented systems like cqrs.

Installation

npm install evented-command

Usage

var evtCmd = require('evented-command')();

Define the command structure [optional]

The values describes the path to that property in the command message.

evtCmd.defineCommand({
  id: 'id',                       // optional
  name: 'name',                   // optional
  context: 'context.name',        // optional
  aggregate: 'aggregate.name',    // optional
  aggregateId: 'aggregate.id'     // optional
});

Define the event structure [optional]

The values describes the path to that property in the event message.

evtCmd.defineEvent({
  correlationId: 'correlationId', // optional
  id: 'id',                       // optional
  name: 'name',                   // optional
  context: 'context.name',        // optional
  aggregate: 'aggregate.name',    // optional
  aggregateId: 'aggregate.id'     // optional
});

Define the id generator function [optional]

you can define a synchronous function

evtCmd.idGenerator(function() {
  var id = require('uuid').v4().toString();
  return id;
});

or you can define an asynchronous function

evtCmd.idGenerator(function(callback) {
  setTimeout(function() {
    var id = require('uuid').v4().toString();
    callback(null, id);
  }, 50);
});

Wire up commands and events

// pass in events from your bus
bus.on('event', function(data){
  evtCmd.emit('event', data);
});

// pass commands to bus
evtCmd.on('command', function(data) {
  bus.emit('command', data);
});

Send commands

var cmd = new Command({
  // id: 'my onwn command id', // if you don't pass an id it will generate one, when emitting the command...
  name: 'changePerson',
  payload: {
    name: 'my name'
  },
  aggregate: {
    id: 8,
    name: 'jack'
  },
  context: {
    name: 'hr'
  }
});

// emit it
cmd.emit();



// if you want to observe the command pass a callback
cmd.emit(function(evt) {

});


// if you want to observe the command that generates any events pass an object like this:
cmd.emit({

  event1: function(evt) {

  },

  event2: function(evt) {

  }

});

Send commands with the speakable api

evtCmd.send('changePerson')
      .for('person') // aggregate name
      .instance('8') // aggregate id
      .in('hr')			 // context name
      .with({
        // id: 'my onwn command id', // if you don't pass an id it will generate one, when emitting the command...
        revision: '12',
        payload: {
        	name: 'jack'
        }
      })
      .go(function(evt) {
        console.log('speakable', evt);
      });

evtCmd.send('multi')
      .for('aggregate')
      .instance('instanceId')
      .in('context')
      .with({
        revision: '43',
        payload: 'data2'
      })
      .go({
        event1: function(evt) {
          console.log('speakable', evt);
        },
        event2: function(evt) {
          console.log('speakable', evt);
        }
      });

License

Copyright (c) 2016 Adriano Raiano

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.