yodata-inbox-poller

simple poller for processing messages from a yodata (LDN) inbox.

Installation

npm install yodata-inbox-poller --save

Usage

const Service = require('yodata-inbox-poller');
const inboxURL = 'https://hsf-test.ds.bhhsresource.com/inbox/';
 
async function handleMessage(message) {
  // do something with the message;
  // optionally return an event
  return {
    type: 'Action',
    actionStatus: 'CompletedActionStatus',
    object: message,
    result: 'some result value'
  }
}
 
const app = Service.create(inboxURL, handleMessage);
 
app.on('dispatch', event => {
  switch (event.type) {
    case Service.eventType.MESSAGE_PROCESS_COMPLETED:
      console.log(event.type, event.result);
      break;
    case Service.eventType.MESSAGE_PROCESS_FAILED:
      console.log(event.type, event.result);
      break;
    default:
      console.log(event.type);
  }
});
 
app.start();

• The queue is polled continuously for messages.
• By default messages are processed one at a time – a new message won't be received until the first one has been processed.

Credentials

By default the poller will look for your api-key in process.env.YODATA_API_KEY

export YODATA_API_KEY=...

If you need to specify your credentials manually, you can use a pre-configured inbox instance.

const Service = require("yodata-inbox-poller");
 
const customInbox = {
  async get(url){
    try {
      // fetch results and return in the following schema
      return {
        type: 'inbox:fetch:completed',
        object: url,
        result: {
          messages: [] // array of fetched messages
      }}  
    }
    catch (error) {
      throw {
        type: 'inbox:fetch:failed',
        object: url,
        error: error.message,
        result: {
          error: error
        }
      }
    }
  }
};
 
 
const app = new Service({
  inboxURL: "https://dave.yodata.me/inbox/",
  handleMessage: handleMessage,
  inbox: customInbox
});
 
app.start();

API

new Poller(options)

Creates a new poller Service.

Options

• inboxURL - String - The inbox URL
• handleMessage - Function - A function to be called whenever a message is received.
• inbox - Object optional pre-configured inbox to use (useful for testing with a mocked inbox);

poller.start()

Start polling for messages.

poller.stop()

Stop polling for messages.

Events

Each poller is an EventEmitter and emits the following events:

// .start()
.emit("service:start") 
 
// .stop(error)
.emit("service:stop")
.emit("service:stop:completed")
 
// .run(next) main event loop
.emit("service:process:start")
.emit("service:process:completed")
.emit("service:process:failed")
 
// _poll()
.emit("inbox:fetch:completed");
.emit("inbox:fetch:failed")
.emit("inbox:empty")
 
// .processResponse(inboxResponse)
.emit("response:process:completed")
.emit("response:process:failed")
 
// .handleMessage(message)
.emit("message:process:completed")
.emit("message:process:failed")