Hello World Observer

The Hello World Observer is a very simple Hyperty to illustrate how Observer Hyperties work. It works together with Hello World Reporter Hyperty and automatically accepts invitations from it to observe changes made on the hello Data Object.

This Hyperty handles a simple hello Data Object:

{
	"$schema": "http://json-schema.org/draft-04/schema#",
	"id": "HelloObject",
	"type": "object",
	"required": ["hello"],
  "properties": {
		"scheme": {
			"constant": "hello"
		},
		"hello": {
			"type": "string"
		}
	}
}

API

The HelloWorldObserver only provides an event handler to the Application to be notified about invitation events from the HelloWorldReporter and events about changes made on the hello Data Object.

addEventListener for Invitations

This function allows to add a callback for invitation events coming from the HelloWorldReporter to be an Observer of the hello Data Object. Invitations are automatically subscribed by the Hyperty and events are .

 addEventListener('invitation', function( Useridentity user) {...})

parameters

function callback the function executed when an invitation event is triggered with the Identity information about the user associated to the inviting Hyperty.

How to use it

hyperty.instance.addEventListener('invitation', function(identity){
	console.log('Invitation coming from user: ', identity.userProfile);
});

addEventListener for changes on Data Object ‘hello’

This function allows to add a callback function to be executed when there are changes on the hello Data Object. The changes event contains the ‘hello’ Data Object.

  addEventListener('hello', function( HelloEvent event) {...})

parameters

function callback the function executed when a change event is triggered with the ‘hello’ Data Object.

How to use it

 hyperty.instance.addEventListener('hello',function(event){
 	console.log('New value for Hello Data Oject: ', event.hello);
 });

Descriptor

The Hyperty descriptor is:

"HelloWorldObserver": {
  "sourcePackage": {
    "sourceCode": ""
    "sourceCodeClassname": "HelloWorldObserver",
    "encoding": "base64",
    "signature": ""
  },
  "hypertyType": ["hello"],
  "cguid": 10004,
  "version": "0.1",
  "description": "Descriptor of HelloWorldObserver Hyperty",
  "objectName": "HelloWorldObserver",
  "configuration": {},
  "sourcePackageURL": "/sourcePackage",
  "language": "javascript",
  "signature": "",
  "messageSchemas": "",
  "dataObjects": [
    "https://catalogue.hybroker.rethink.ptinovacao.pt/.well-known/dataschema/HelloWorldDataSchema"
  ],
  "accessControlPolicy": "somePolicy"
}

Project Details

Date: Jun 1, 2015

Description: Monitors Hello Data Object Changes

Author: Paulo Chainho

Categories: hello-world

Tagged: hello-world

Client: reTHINK Project

Catalogue URL: https://catalogue.hybroker.rethink.ptinovacao.pt/.well-known/hyperty/HelloWorldObserver

Live Demo: /demos/hello-world-observer/