obseriot

Simple observer pattern

Install

npm install obseriot

Usage

Define event

Object with a handler.name and handler.action .

• handler.name => Event name
• handler.action => Return the parameters to be provided to the listener
  • Array is provided as a variadic argument
  • Can be provide a variety of types. String, Object, Function, whatever

const urlChange = {
    handler: {
        name: 'url_change',
        action ( collection, id, action ) {
            // Some processing and formatting
            return [ collection, id, action ]
        }
    }
}

Listen and Notify

// obseriot.listen( event object , callback function )
obseriot.listen( urlChange, ( ...arg ) => {
    console.log( arg ) // => 'shop', 1, 'detail'
} )
 
// obseriot.notify( event object , parameters )
obseriot.notify( urlChange, 'shop', 1, 'detail' )

One time listener

// obseriot.once( event object , callback function )
obseriot.once( urlChange, ( ...arg ) => {
    console.log( arg )
} )

Remove listeners

Remove all registered listeners.

// obseriot.remove( event object )
obseriot.remove( urlChange )

Remove one registered listener.

// obseriot.remove( event object, callback function )
const callback = ( ...arg ) => {
    console.log( arg )
}
obseriot.listen( urlChange, callback ) // Listen to the named function.
obseriot.remove( urlChange, callback ) // Remove!

How to use like Flux

Define Action

export const increment = {
    handler: {
        name: 'action_increment',
        action ( num = 1 ) {
            return [ num ]
        }
    }
}

Define Store

import {increment} from './action/increment'
import obseriot from 'obseriot'
 
export const count = {
    state: 0,
    handler: {
        name: 'store_count',
        action () {
            return [ count.state ]
        }
    }
}
 
obseriot.listen( increment, num => {
    count.state = count.state + num
    obseriot.notify( count )
} )

Your Component

import {increment} from './action/increment'
import {count} from './store/count'
import obseriot from 'obseriot'
 
// Action in somewhere components
obseriot.notify( increment, 1 )
 
// Listen to Store update
obseriot.listen( count, newCount => {
    console.log( newCount ) // => 1
} )