@emisor/core

Advanced event emitter core

Usage no npm install needed!

<script type="module">
  import emisorCore from 'https://cdn.skypack.dev/@emisor/core';
</script>

README

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 |

off

unsubscribe from a event

  • If no event is given, all subscribers will be unsubscribed
  • if no handler is given all subscribers of the given event will be unsubscribed

params

| name | type | description | | - | - | - | | event | string\|Symbol | unsubscribe to a specific event | | handler | function | unsubscribe to a specific handler |

emit

Emit a event

params

| name | type | | - | - | | event | string\|Symbol | | payload | any | | tags | any[]\|any |

Plugins

hooks

emit