Introduction
This project is inspirated by jamuhl.
Project goal is to provide a simple command/event handling for evented systems like cqrs.
Installation
$ npm install nodeEventedCommand
Simple usage
// get the hub
var hub = require('nodeEventedCommand').hub;
// initialize the hub by passing the function that gets the command id from the event
hub.init(
function(evt) {
return evt.commandId;
}
);
// and the command
var Command = require('nodeEventedCommand').Command;
Advanced usage with own instance
// get the hub
var hub = require('nodeEventedCommand').hub.create();
// initialize the hub by passing the function that gets the command id from the event
hub.init(
function(evt) {
var idEndIndex = evt.id.indexOf('_event');
var id = evt.id.substring(0, idEndIndex);
return id;
}
);
// and the command
var Command = require('nodeEventedCommand').Command.create(hub);
Wire up commands and events
// pass in events from your bus
bus.on('events', function(data){
hub.emit('events', data);
// use it with wildcards for mulit callback
// hub.emit('event:' + data.event, data);
});
// pass commands to bus
hub.on('commands', function(data) {
bus.emit('commands', data);
});
Send commands
var cmd = new Command({
command: 'changePerson',
payload: {
id: 8,
name: 'my name'
}
});
// 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) {
}
});
License
Copyright (c) 2012 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.