YohGo Evently

YohGo Evently is a machinery based package that manages events asynchronously in an event-based architecture

---

• Requirements
• Features
• Installation
• Usage
  • Event Publishing
  • Event Listening

---

Requirements

• Go (1.5+)
• Machinery (1+)

---

Features

• Lightweight and fast
• Native Go implementation
• Supports redis and AMQP message brokers

---

Installation

Simply install the package to your $GOPATH with the go tool from shell:

$ go get github.com/RichardKnop/machinery/v1
$ go get github.com/yohgo/evently

Make sure Git is installed on your machine and in your system's PATH.

---

Usage

YohGo Evently is a package that manages events asynchronously in an event-based architecture. Evently is based on Machinery which is an asynchronous task queue/job queue based on distributed message passing.

Event Publishing

Example of using the evently package for event publishing:

import (
    "github.com/yohgo/evently"
)

// A string map containing the event publisher's settings
settings := map[string]string{
    "broker"           : "A url to a redis or AMQP broker",
    "downstream_queue" : "The default downstream event queue",
    "upstream_queues"  : "A colon-separated list of upstream event queues",
    "result_backend"   : "A url to the backend result storage",
            "amqp_exchange" : "An AMQP exchange", // (only when broker = AMQP)
            "amqp_exchange" : "An AMQP exchange type", // (only when broker = AMQP)
            "amqp_exchange" : "An AMQP binding key", // (only when broker = AMQP)
}

// Creating a new event publisher
publisher := evently.NewEventPublisher(settings)

// Attempting to publish a user.updated event
if !publisher.EventPublisher.Publish("user.updated", user).IsOK() {
    return errors.New("Unable to publish the user.updated event")
}

For more details regarding event publisher configuration check Machinery Documentation

Event Listening

Example of using the evently package for event listening:

import (
    "github.com/yohgo/evently"
)

// An event handler method (takes a json string)
func eventHandler(JSONData string) error {
    /* Event handling logic */
}

settings := map[string]string{
    "broker"           : "A url to a redis or AMQP broker",
    "downstream_queue" : "The default downstream event queue",
    "upstream_queues"  : "A colon-separated list of upstream event queues",
    "result_backend"   : "A url to the backend result storage",
            "amqp_exchange" : "An AMQP exchange", // (only when broker = AMQP)
            "amqp_exchange" : "An AMQP exchange type", // (only when broker = AMQP)
            "amqp_exchange" : "An AMQP binding key", // (only when broker = AMQP)
}

// A map of event/handler pairs
handlers := map[string]interface{}{
    "user.updated": eventHandler
}

// Creating a new event listener
listener := evently.NewEventListener("user.listener", settings, handlers)

// Attempting to start the user.updated event listener
if !listener.EventPublisher.Eavesdrop().IsOK() {
    return errors.New("Unable to start the event listener")
}

For more details regarding event listener configuration check Machinery Documentation