import Emitter from 'schq/src/emitter/index.js'

public class | source

Emitter

Object of event emitters that use observable to transmit data based off of the example at https://goo.gl/gw1Z3I with a few more bells and whistles.

Example:

let emitter = new Emitter();

let subcription = emitter.listen('data', function (data) {
  console.log('data: ' + data);
});

emitter.emit('data', 'foo');
// => data: foo

// Destroy the subscription
subscription.dispose();

TODO:

write lost data method for events for testing.

Constructor Summary

Public Constructor
public	constructor(lostCount: Number)

Member Summary

Public Members
public	subjects: Object

Method Summary

Public Methods
public	emit(name: String, data: *) Emitter.emit: Emits event to a subscribed listener
public	hasObserver(name: String): Boolean Emitter.hasObserver: Access the hasObserver property to check if subject has an observer.
public	listSubjects(): Array Emitter.listSubjects: Returns a list of current Subjects.
public	listen(name: String, handler: Function): Function Emitter.listen: listens for an event name and handles it via the handle callback function.
public	unlisten(name: String) Emitter.unlisten: unlisten from a single Subject
public	unlistenAll() Emitter.unlistenAll: unlisten from all Subjects

Public Constructors

public constructor(lostCount: Number) source

Params:

Name	Type	Attribute	Description
lostCount	Number	optional default: 10	Number of events to capture if an event if being emitted but not subscribed.

Public Members

public subjects: Object source

Public Methods

public emit(name: String, data: *) source

Emitter.emit: Emits event to a subscribed listener

Params:

Name	Type	Attribute	Description
name	String		Name of variable
data	*		Any value to transmit

Example:

let emitter = new Emitter();

let subcription = emitter.listen('data', function (data) {
  console.log('data: ' + data);
});

emitter.emit('data', 'foo');
// => data: foo

public hasObserver(name: String): Boolean source

Emitter.hasObserver: Access the hasObserver property to check if subject has an observer. This comes in handy in testing.

Params:

Name	Type	Attribute	Description
name	String		Name of variable

Return:

Boolean

Example:

let emitter = new Emitter();

console.log(emitter.hasObservers(data));
// => false

var subscription = emitter.listen(
  (x) => {
    console.log(x);
  });

console.log(emitter.hasObservers(data));
// => true

public listSubjects(): Array source

Emitter.listSubjects: Returns a list of current Subjects. Each will have a preceding $ tag.

Return:

Array

Array of Strings

Example:

let emitter = new Emitter();

let subcription = emitter.listen('data', function (data) {
  console.log('data: ' + data);
});

console.log(emitter.listSubjects());
// => ['$data']

public listen(name: String, handler: Function): Function source

Emitter.listen: listens for an event name and handles it via the handle callback function. It is the subscribe method of an observable. If you wish to handle error and have a complete function use method subject

Params:

Name	Type	Attribute	Description
name	String		Name of variable
handler	Function		A function to handle events

Return:

Function

A unlisten function via varName.dispose()

Example:

let emitter = new Emitter();

let subcription = emitter.listen('data', function (data) {
  console.log('data: ' + data);
});

subcription.dispose()

public unlisten(name: String) source

Emitter.unlisten: unlisten from a single Subject

Params:

Name	Type	Attribute	Description
name	String		Name of variable

Example:

let emitter = new Emitter();

emitter.listen('data1', (data)=> console.log(data));
emitter.listen('data2', (data)=> console.log(data));

console.log(emitter.listSubjects());
// => ['$data1', '$data2']

emitter.unlisten('data1');

console.log(emitter.listSubjects());
// => ['$data2']

public unlistenAll() source

Emitter.unlistenAll: unlisten from all Subjects

Example:

let emitter = new Emitter();

emitter.listen('data1', (data) => console.log(data));
emitter.listen('data2', (data) => console.log(data));
emitter.listen('data3', (data) => console.log(data));

console.log(emitter.listSubjects());
// => ['$data1', '$data2', '$data3']

emitter.unlistenAll();

console.log(emitter.listSubjects());
// => []