@emisor/core NPM

Emisor core

:construction: work in progress

Events

Emisor supports 2 type of events, Symbol and string. String based events are more powerful then the "simpler" Symbol based events. String based events support namespaces, the default namespace separator is ..

Channel filter

Channel filters can only be used by string based events and the following filters are supported:

Wildcard *

You can only filter on 1 or more namespaces you can not filter on the event substring, meaning that test.* is valid filter and test* is a invalid filter.

Wildcard filter: `*`

usage	description
`*`	subscribe to any event
`namespace.*`	subscribe to any event that starts with the namespace as well to the exact match of the namespace
`namespace.*.namespace`	You can use a wildcard for one part of the namespace.

Emitter.on('test.*', (d) => console.log(d));
//This will trigger the subscriber
Emitter.emit('test', 1);
//but also any event that starts with the test namespace
Emitter.emit('test.test', 2);
Emitter.emit('test.test.etc', 3);

Emitter.on('car.*.door.open', (d) => console.log(d));
//These events will trigger the subscriber
Emitter.emit('car.left.door.open', true);
Emitter.emit('car.right.door.open', true);

Plugin postfix

Some plugin support to set options via the postfix of the event string, for example the count plugin can be triggered via this.should.be.called.once:#1. The default postfix separator is :

Plugin prefix

Some plugin can be triggered via a single prefix chart of the event stings, for example the history plugin can be triggered via >this.is.the.same.as.history.true

Methods

`on`

Subscribe to a event.

params

name	type	description
event	`string\\|Symbol\\|string[]\\|Symbol[]`	event to subscribe to
handler	`function`	event handler
options	`object`	options that wil trigger plugins

example

// Subscribe to the foo
Emitter.on('foo', () => {})
// Subscribe to both foo and bar with the same handler
Emitter.on(['foo', 'bar'], () => {})

The handler will receive 2 params the first one the payload of the triggered event, second one the $event object that will have the following property:

key	type	description
time	`number`	unix timestamp of publish time
event	`string\\|Symbol`	event that triggered the handler
handler	`function`	the handler it self
tag	`any[]`	events can have tags, mostly used by plugins