amq-broker

Installation

$ npm install amq-broker --save

Usage

Set up process variable CLOUDAMQP_URL or AMQP_URL pointing to the broker instance.

//module will lookup process variable and establish connection
const msgBroker = require("amq-broker");

//get the handle to Events construct
const Events = msgBroker.Events;

//Publish directly to an exchange named 'notify' with routing key 'create'

msgBroker.publish("notify", "createx", Events.simple({ name: "tx" }));

//Publish directly to a queue

msgBroker.sendToQueue(
  "transaction",
  Events.simple({ source: "shopify", id: "12345", amount: "45 SGD" })
);

//Consume directly from a queue
msgBroker.consume("transaction", (response) =>
  console.log("Recieved response : " + response)
);

//To release connections on exit, set up closeonExit with an optional handler
//Once the process terminate, connections will be released and the optional handler will be invoked

msgBroker.closeOnExit((err, success) => {
  if (err) {
    console.error("Error while releasing MQ connections", err);
    return;
  }
  console.log("Successfully released MQ connections");
});

Events

Events are data wrappers. Currently supports "simple" and "chained".

const msgBroker = require("sg-lab-broker");

//get the handle to Events construct
const Events = msgBroker.Events;

//create a simple event
let shopping = { source: "txn", id: "Tx1245", amount: "10 SGD" };

//wrap that in event using simple construct
let simpleEvent = Events.simple(shopping);

//create one more data
let sms = { to: "+3111", message: "Hello World!!" };

//lets create a chained event
let chainedEvent = Events.chained()
  .add("txn", shopping) //add shopping to the chain
  .add("sms", sms) //add sms also to the chain
  .build();

//Events construct helps to retrieve data within consumers
let smsData = Events.getData(chainedEvent, "sms");
//or
let shoppingData = Events.getData(simpleEvent);

Queue operations

//create a queue named 'queue-name'
msgBroker
  .createQueue("queue-name", {})
  .then((data) => console.log(data))
  .catch((error) => console.log(error));

//bind the queue, 'queue-name' to the exchange, 'exchange-name' using topic, '#.routing-key.#'
// #.routing-key.# means match any message which it's topic contains the string '.routing-key.'
msgBroker
  .bindQueue("queue-name", "exchange-name", '"#.routing-key.#')
  .then((data) => console.log(data))
  .catch((error) => console.log(error));

//unbind the queue, 'queue-name' for the topic, '#.routing-key.#' from the exchange, 'exchange-name'
msgBroker
  .unbindQueue("queue-name", "exchange-name", '"#.routing-key.#')
  .then((data) => console.log(data))
  .catch((error) => console.log(error));

//delete the queue named 'queue-name'
msgBroker
  .deleteQueue("queue-name", {})
  .then((data) => console.log(data))
  .catch((error) => console.log(error));