HOE - Higher Order Events

HOE is an event handler especially designed keeping virtual dom libraries in mind.

Table of Contents

• Installation
• Usage
• Action
• Example
• API

Installation

via npm:

$ npm install hoe --save

via CDN:

<script src="https://unpkg.com/hoe/dist/hoe.js"></script>

Usage

import * as hoe from 'hoe'

// Logs the `Actions`
const actionListener = action => {
  console.log(action)
}

// Creating a new instance
const emitter = hoe.create(actionListener)

// Sample Usage
const component = (emitter) => (
  <div>
    <button onClick={emitter.of('hello').emit}>Hello</button>
    <button onClick={emitter.of('bye').emit}>Bye</button>
  <div>
)

// vNode being returned from the component
const vNode = component(emitter)

On clicking on buttons, the actionListener logs the following Actions —

// Hello
{type: 'hello', value: [ClickEvent]}

// Bye
{type: 'bye', value: [ClickEvent]}

The value in this case is the actual click event.

Action

HOE converts DOM Events into an Action Type. An Action has two properties —

• type : Its a string|number identifier which depicts the originator of event. For example — if an event is fired from the side navigation, the corresponding Action could have a type as SIDE_NAV.
• value: Value is the payload that needs to be transmitted via the Action. In most cases it would be the DOM event. In some cases the value it self could be an Action. This is especially useful when the nesting of components is really deep and one would like to namespace actions based on the hierarchy of components.

Example

• Deeply nested components
• Dynamically created stateful components

API

hoe.create(actionListener)

This is the constructor function for creating the action emitter. It takes in a single listener and returns an instance of Hoe.

Usage

import * as hoe from 'hoe'

const actionListener = (event) => {
  // do something with that event
}

const emitter = hoe.create(actionListener) // returns a Hoe

emitter.of(type)

It takes in a type which is of type string|number and returns a new instance of Hoe. For Eg:

import * as hoe from 'hoe'

const h0 = hoe.create(listener)
const h1 = h0.of('A').of('B').of('C')

emitter.emit(value)

It is available on all Hoe instances. It takes in any value and based on the type it dispatches an action.