@veams/vent

Vent (@veams/vent)

Vent is a simple publish and subscribe system you can use to communicate between modules independently.

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Installation

NPM

npm install @veams/vent --save

Yarn

yarn add @veams/vent

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Standalone Usage

Use Vent to trigger events globally and subscribe to it!

Example

Default events like click, resize and more

import createVent from '@veams/vent';

const Vent = createVent(); // If using the plugin you do not need this and have the functionality available in the namespace (like `Veams.Vent`)

// Let's add a throttle to the scroll event and trigger that
window.onscroll = Veams.helpers.throttle((e) => {
    Vent.publish('scroll', e);
}, 200);

// Now we can easily catch that ...
Vent.subscribe('scroll', () => {
    console.log('Throttled scroll captured ... ');
});

Custom events

import createVent from '@veams/vent';

const Vent = createVent(); // If using the plugin you do not need this and have the functionality available in the namespace (like `Veams.Vent`)

const dataHandler = (data) => {
    // Make something with the data ...
    console.log('my custom data received by publish(): ', data);
})

Vent.subscribe('custom:event', dataHandler);

Vent.subscribe('resize', () => {
    // First we want to publish it, so that `dataHandler()` will be executed
    Vent.publish('custom:event', {
        testData: 'My test data'
    });
	
    // After that we unsubscribe to make sure that `dataHandler()` is only executed once
    Vent.unsubscribe('custom:event', dataHandler);
});

Veams Plugin

Additionally we have a plugin in place giving you the flexibility to use @veams/vent in the Veams eco system. Veams exposes a global event object (Veams.EVENTS) which can be used and extended by this plugin.

The module extends the default EVENTS object of Veams when you pass the option called furtherEvents.

Usage

import Veams from '@veams/core';
import VentPlugin from '@veams/vent/lib/plugin/vent';
import EVENTS from './custom-events';

// Intialize core of Veams
Veams.onInitialize(() => {
    // Add plugins to the Veams system
    Veams.use(VentPlugin, {
        furtherEvents: EVENTS
    });
});

Options

Option	Type	Default	Description
furtherEvents	{Object}	[false]	Add your custom events to the global events object of Veams.

Api

When enabled the Api provides a way to subscribe and unsubscribe from global events and publish to the subscribers.

Vent.subscribe(name:string, callback:function)

alias: .on()

• @param {String} name - Event name which you subscribed to.
• @param {Function} callback - The callback function which get executed when event is triggered.

Vent.unsubscribe(name:string, callback:function)

alias: .off()

• @param {String} name - Event name which you have subscribed to.
• @param {Function} callback - The callback function which is registered.

Vent.publish(name:string, obj?:object, scope?:any)

alias: .trigger()

• @param {String} name - Event name which you have subscribed to.
• @param {Object} obj - Optional custom data object which you can pass.
• @param {scope} any - Optional scope/context on which you want to execute .call().