Hookable

Awaitable hooks for Node.js and Browser

Install

Using yarn:

yarn add hookable

Using npm:

npm install hookable

Usage

Extend your base class from Hookable:

import Hookable from 'hookable'

export default class Foo extends Hookable {
  constructor() {
    // Call to parent to initialize
    super()
    // Initialize Hookable with custom logger
    // super(consola)
  }

  async someFunction() {
    // Call and wait for `hook1` hooks (if any) sequential
    await this.callHook('hook1')
  }
}

Inside plugins, register for any hook:

const lib = newFooLib()

// Register a handler for `hook2`
lib.hook('hook2', async () => { /* ... */ })

// Register multiply handlers at once
lib.addHooks({
  hook1: async () => { /* ... */ },
  hook2: [ /* can be also an array */ ]
})

Unregistering hooks:

const lib = newFooLib()

const hook0 = async () => { /* ... */ }
const hook1 = async () => { /* ... */ }
const hook2 = async () => { /* ... */ }

// The hook() method returns an "unregister" function
const unregisterHook0 = lib.hook('hook0', hook0)
const unregisterHooks1and2 lib.addHooks({ hook1, hook2 })

/* ... */

unregisterHook0()
unregisterHooks1and2()

// or

lib.removeHooks({ hook0, hook1 })
lib.removeHook('hook2', hook2)

Triggering a hook handler once:

const lib = newFooLib()

const unregister = lib.hook('hook0', async () => {
  // Unregister as soon as the hook is executed
  unregister()

  /* ... */
})

Hookable class

constructor(logger)

Custom logger. Default logger is console but you can use your own or consola.

It should be an object implementing following functions:

• warn
• error
• fatal (optional)

hook (name, fn)

Register a handler for a specific hook. fn must be a function.

Returns an unregister function that, when called, will remove the registered handler.

hookOnce (name, fn)

Similar to hook but unregisters hook once called.

Returns an unregister function that, when called, will remove the registered handler before first call.

addHooks(configHooks)

Flatten and register hooks object.

Example:

hookable.addHooks({
  test: {
    before: () => {},
    after: () => {}
  }
})

This registers test:before and test:after hooks at bulk.

Returns an unregister function that, when called, will remove all the registered handlers.

async callHook (name, ...args)

Used by class itself to sequentially call handlers of a specific hook.

deprecateHook (old, name)

Deprecate hook called old in favor of name hook.

deprecateHooks (deprecatedHooks)

Deprecate all hooks from an object (keys are old and values or newer ones).

removeHook (name, fn)

Remove a particular hook handler, if the fn handler is present.

removeHooks (configHooks)

Remove multiple hook handlers.

Example:

const handler = async () => { /* ... */ }

hookable.hook('test:before', handler)
hookable.addHooks({ test: { after: handler } })

// ...

hookable.removeHooks({
  test: {
    before: handler,
    after: handler
  }
})

Credits

Extracted from Nuxt.js hooks system

Original author Sébastien Chopin

Thanks to Joe Paice for donating hookable package name

License

MIT - Made with 💖 by Nuxt.js team!