Home Web Front-end JS Tutorial Broadcasting and receiving Vue2.0 events (observer mode)

Broadcasting and receiving Vue2.0 events (observer mode)

May 30, 2018 am 11:55 AM
take over

This article mainly introduces the broadcast and reception of Vue2.0 events (observer mode). Now I share it with you and give it as a reference.

1.Vue1.0 event broadcasting and reception (observer mode)

This method of communicating data between early vue1.0 components , the vue official website provides two methods $dispatch and $broadcast.

But these two methods will be abandoned after vue2.0. The following reasons are given by the vue official website

Official Document

2.Vue2.0 event broadcasting and reception (observer mode)

$emit, $on, $off can be used in vue2.0 Distribute, monitor, and cancel listening events respectively. The simplest official upgrade suggestion is to use a centralized event handler, and it also clearly states that an empty vue instance can do this, because the Vue instance implements an event distribution interface.

Please look at the code directly. During initialization, add an empty vue object named eventhub to the data in the global App.vue file:


new Vue({
 el: '#app',
 router,
 render: h => h(App),
 data: {
  eventHub: new Vue()
 }
})
Copy after login


In this way, we can call the event transmitting and receiving methods in any component. So how does the component transmit and receive? Please look at the front code:

The calling event in a certain component triggers


//通过this.$root.eventHub获取此对象
//调用$emit 方法
this.$root.eventHub.$emit('你的事件名字', 你的需要传送的数据)
Copy after login


and above It means that a component emits an event, which can be understood as I sent a broadcast. If other components need my broadcast, please adjust to my channel. This channel is your event name, and the content of the broadcast is what you sent. Data, then the question is, how do other components receive it? Please see the code


this.$root.eventHub.$on('你的事件名字', (传送的数据)=>{
  handle(yourData)
} )
Copy after login


Components that need to listen to the broadcast can receive it through our globally defined eventHub.$on. The channel is the name of the broadcast event, and the number in the callback is the broadcast content.

3. Write it more concisely

If you have a certain understanding of js, you may know that js has a prototype. This is the main thing Add additional properties to js objects.

For example, declare an object


##

var person=function(){
  this.name="小明";
}
Copy after login


Then we extend this object, such as adding A method of speaking, at this time the useful thing of prototype comes in handy



person.prototype.say=function(){
  alert(this.name);
}
Copy after login


This is expanded The original function object is


when called directly



 var a=new person();
Copy after login


person.say( ); Xiao Ming will pop up. The advantage of this is that no additional memory will be generated, and all instantiated objects will inherit this method from the prototype.


Vue is actually a js class library. Of course, you can also use the magical thing of prototype to expand custom properties. Here are some tips:


Initialize Vue. Add this sentence before app:



Vue.prototype.$eventHub= Vue.prototype.$eventHub || new Vue()
Copy after login


so that we can directly call $eventHub

# inside the component
##The following is a re-transformation of the above method:


Published by


##
//通过this.$root.eventHub获取此对象
//调用$emit 方法
this.$eventHub.$emit('你的事件名字', 你的需要传送的数据)
Copy after login


Receiver


 this.$eventHub.$on('你的事件名字', (传送)=>{
    handle(yourData).
  } )
Copy after login


##4. Close broadcast

To turn off the broadcast, we mainly use $off (your event name) to cancel listening!

The above is what I compiled for everyone. I hope it will be helpful to everyone in the future.


Related articles:

The problem and solution of {{}} flickering when vue renders

A brief discussion on js acquisition ModelAndView value problem

Solution to vue page loading flickering problem



The above is the detailed content of Broadcasting and receiving Vue2.0 events (observer mode). For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. Best Graphic Settings
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. How to Fix Audio if You Can't Hear Anyone
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
WWE 2K25: How To Unlock Everything In MyRise
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How do I create and publish my own JavaScript libraries? How do I create and publish my own JavaScript libraries? Mar 18, 2025 pm 03:12 PM

Article discusses creating, publishing, and maintaining JavaScript libraries, focusing on planning, development, testing, documentation, and promotion strategies.

How do I optimize JavaScript code for performance in the browser? How do I optimize JavaScript code for performance in the browser? Mar 18, 2025 pm 03:14 PM

The article discusses strategies for optimizing JavaScript performance in browsers, focusing on reducing execution time and minimizing impact on page load speed.

What should I do if I encounter garbled code printing for front-end thermal paper receipts? What should I do if I encounter garbled code printing for front-end thermal paper receipts? Apr 04, 2025 pm 02:42 PM

Frequently Asked Questions and Solutions for Front-end Thermal Paper Ticket Printing In Front-end Development, Ticket Printing is a common requirement. However, many developers are implementing...

How do I debug JavaScript code effectively using browser developer tools? How do I debug JavaScript code effectively using browser developer tools? Mar 18, 2025 pm 03:16 PM

The article discusses effective JavaScript debugging using browser developer tools, focusing on setting breakpoints, using the console, and analyzing performance.

How do I use source maps to debug minified JavaScript code? How do I use source maps to debug minified JavaScript code? Mar 18, 2025 pm 03:17 PM

The article explains how to use source maps to debug minified JavaScript by mapping it back to the original code. It discusses enabling source maps, setting breakpoints, and using tools like Chrome DevTools and Webpack.

How do I use Java's collections framework effectively? How do I use Java's collections framework effectively? Mar 13, 2025 pm 12:28 PM

This article explores effective use of Java's Collections Framework. It emphasizes choosing appropriate collections (List, Set, Map, Queue) based on data structure, performance needs, and thread safety. Optimizing collection usage through efficient

TypeScript for Beginners, Part 2: Basic Data Types TypeScript for Beginners, Part 2: Basic Data Types Mar 19, 2025 am 09:10 AM

Once you have mastered the entry-level TypeScript tutorial, you should be able to write your own code in an IDE that supports TypeScript and compile it into JavaScript. This tutorial will dive into various data types in TypeScript. JavaScript has seven data types: Null, Undefined, Boolean, Number, String, Symbol (introduced by ES6) and Object. TypeScript defines more types on this basis, and this tutorial will cover all of them in detail. Null data type Like JavaScript, null in TypeScript

Getting Started With Chart.js: Pie, Doughnut, and Bubble Charts Getting Started With Chart.js: Pie, Doughnut, and Bubble Charts Mar 15, 2025 am 09:19 AM

This tutorial will explain how to create pie, ring, and bubble charts using Chart.js. Previously, we have learned four chart types of Chart.js: line chart and bar chart (tutorial 2), as well as radar chart and polar region chart (tutorial 3). Create pie and ring charts Pie charts and ring charts are ideal for showing the proportions of a whole that is divided into different parts. For example, a pie chart can be used to show the percentage of male lions, female lions and young lions in a safari, or the percentage of votes that different candidates receive in the election. Pie charts are only suitable for comparing single parameters or datasets. It should be noted that the pie chart cannot draw entities with zero value because the angle of the fan in the pie chart depends on the numerical size of the data point. This means any entity with zero proportion

See all articles