pretty-event-emitter v1.0.0

EventEmitter

中文文档

Why

By using it, you can easily register and trigger events. At the same time, you can observe the snapshot information of the event handler execution in the console in real time.

Also,You can extend your business module with this base class, such as:

import EventEmitter from "pretty-event-emitter"

class YourClass extends EventEmitter {
  constructor(config) {
    super(config)
  }
  ...your code
}

Install

A lightweight event monitoring processor. Support cmj、esm、umdmodule.

npm i -S pretty-event-emitter

Usage

This is just the most basic way to use it. For more usage, please refer to Support Api

// esm
import EventEmitter from "pretty-event-emitter"
// or cmj
const EventEmitter = require("pretty-event-emitter")

const eventsBus = new EventEmitter()

eventsBus.on("download", (status) => console.log(status))

eventsBus.emit("download", true)

eventsBus.off("download")

eventsBus.watch() // monitor the operation of all registered processors

Support Api

eventsBus.on(event,handler)

Register for one or more events at the same time

• example

eventsBus.on("download", (...args:[]) => {...}) // only register a single handler with eventName download
eventsBus.on("download.image", (...args:[]) => {...}) // register a single handler with eventName download and type image
eventsBus.on("download pay.membership", (...args:[]) => {...}) // at the same time register a single handler with eventName download, and eventName pay with type membership

• attention

  • Although multiple events are registered, they all have the same event handler
  • An event may correspond to multiple different types of event handlers

eventsBus.emit(event,...args)

Trigger event handler, support event name (batch) or event name with type (exact)

• example

eventsBus.on('download.privilege download.image',(status,type)=>{
  // The processor function here indicates what should be done according to the status and type after downloading the privilege or image
})

// After registering, you will find your event hub looks like this

// eventsBus.events
{
  download:[{type:'privilege',handler:(status)=>{...},{type:'image',(status)=>{...}}}]
}

**batch mode**
eventsBus.emit('download') // both of download.privilege and download.image handler will be trigger

**exact mode**
eventsBus.emit('download.privilege') // only download.privilege will be trigger

eventsBus.emitType(type)

Trigger handlers by event type

• example

eventsBus.on('download.privilege pay.privilege',(status,type)=>{
  // do something with args.status and args.type
})

// After registering, you will find your event hub looks like this

// eventsBus.events
{
  download:[{type:'privilege',handler:(status,type)=>{...}}],
  pay:[{type:'privilege',handler:(status,type)=>{...}}],
}

**type mode**
eventsBus.emitType('privilege',true,'font') // both of download.privilege and pay.privilege handler will be trigger

eventsBus.watch()

:heart_eyes_cat: In order to be able to easily know the execution of the event handler. Provides a watch method that returns the order of execution of all events, parameters and return values, and call time.

So if you get some doubts when using it, you can try calling it.

const watcher = eventsBus.watch()
console.log(watcher)

eventsBus.off(event)

Destroy event handler, support event name (batch) or event name with type (exact)

• example

**batch mode**
eventsBus.off('download') // all handlers with eventName download will be destroyed

**exact mode**
eventsBus.off('download.privilege') // handler with eventName download and type privilege will be destroyed

eventsBus.offType(type)

Destroy event handlers of a certain type

• example

eventsBus.offType("privilege")

eventsBus.offAll()

Destroy all registered events and event handlers

• example

eventsBus.offAll()

eventsBus.countOfEventHandlers(event)

Returns the number of handler functions for the given event

eventsBus.on("download.privilege pay.privilege download.font", (status, type) => {
  // do something with args.status and args.type
})

eventsBus.countOfEventHandlers("download") // 2
eventsBus.countOfEventHandlers("pay") // 1

eventsBus.countOfTypeHandlers(type)

Returns the number of handler functions for the given type

eventsBus.on("download.privilege pay.privilege download.font delete.privilege", (status, type) => {
  // do something with args.status and args.type
})

eventsBus.countOfTypeHandlers("privilege") // 3
eventsBus.countOfTypeHandlers("font") // 1

eventsBus.eventKeys

Returns the name of the event when it has been registered

eventsBus.on("download.privilege pay.privilege", (status, type) => {
  // do something with args.status and args.type
})

eventsBus.eventKeys // ['download','pay']

eventsBus.countOfEvents

Returns the name of the event when it has been registered

eventsBus.on("download.privilege pay.privilege", (status, type) => {
  // do something with args.status and args.type
})

eventsBus.countOfEvents // 2

eventsBus.countOfAllHandlers

Returns the number of all event handlers that have registered for the event

eventsBus.on("download.privilege pay.privilege download.font", (status, type) => {
  // do something with args.status and args.type
})

eventsBus.countOfAllHandlers // 3

TODO

• Real-time log printing can be supported by enabling debug mode (currently, only viewing and executing snapshots by calling eventsBus.watch() is supported)
• Add maximum number of event handlers
• Beautify console log information

Contributing

Feel free to submit issues or prs to me.