Package Exports

magic-hook

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Readme

magic-hook

Extends functions with pre hooks. Inspired by hooks-js.

Installation

$ npm install --save magic-hook

Motivation

Suppose you have an object with a save method.

It would be nice to be able to declare code that runs before save. For example, you might want to run validation code before every save. Or you might want to create plugins that will modify the input parameters of your save method.

Why no post hook as well?

post hooks are the same as events, so no need to replicate the functionality of a regular event emitter.

Usage

You can add pre hooks to extend your methods.

const magicHook = require('magic-hook')

let log = magicHook(function(msg) {
  console.log(msg)
})

let messageNumber = 0
function counterHook(next, msg) {
  messageNumber++
  next('message #' + messageNumber + ': ' + msg)
}
log.pre('log', counterHook);

// will output "message #1: Hello world!" to the console
log('Hello world!')

// hooks can be removed
log.removePre(counterHook)

// will output "Hello world!" to the console, because the counter hook was removed
log('Hello world!')

// To remove all pres associated with a hook just call removePre with no arguments:
log.removePre()

License

The MIT License (MIT)