Nocms-mq-api NPM

NoCMS MQ Api

Commit message format and publishing

This repository is published using semantic-release, with the default AngularJS Commit Message Conventions.

Fluent API for handling rabbit mq messaging in NoCMS.

Installation

npm install nocms-mq-api --save

Examples

Send a message

const mq = require('mq');

// Send a message of certain type
const msgObj = {
  data: { foo: 'Foo' }
};

mq.send('my-message', msgObj);

Subscription

mq.connect(config)
  .subscribe('my-message', (msg) => {
    console.log(msg.data.foo); // --> Foo
  });

Responding

This example has a handler responding to ping messages with the value pong and the other way around.

mq.connect(config)
  .subscribe('ping-message', (msg) => {
    const response = { value: msg.data.value === 'ping' ? 'ping' : 'pong' };
    mq.respond(msg, null, response)
  });

const pingMsg = {
  data: value: 'ping',
};

const responseHandler = (err, response) => {
  console.log(response.value); // --> pong
};

mq.send('ping-message', pingMsg, responseHandler);
mq.respond(msg, null, response)

The Message Object

{
  type: 'Name of message type',
  userToken: 'An optional token for identifying an end user',
  adminToken: 'An optional token identifying a NoCMS user',
  data: 'An object or value representing the message payload',
  originId: 'A generated read only guid for a message'
}

API

connect, (config)

Establish connection to and AMQP server. config = { host: Address to the server, login: mq user name, password: mq password, vhost: mq vhost, exchange: name of the exchange to connect to, queue: name of the queue to subscribe to }

send, (messageObj, callback)

Publishes message of type messageName on the queue.

If callback is provided, this will be called if a response message is returned.

subscribe, (messageName, handlerFunction)

Subscribe to a message of a certain type. The handler function will be invoked with the message object as a single argument.

respond, (originalMessage, error, response)

The respond function takes the original message object and publishes a new message of type response-message referencing the original message by it's originId.