


DOM elements have some standard events. Generally, you only need to use onclick=function. However, when you need to add multiple events to DOM elements, delete events, or use Javascript to encapsulate controls, add When customizing events, the onclick=function method is not enough, but the browser has addEventListener and attachEvent methods to call, thus simulating an event triggering mechanism similar to event delegation in C#!
/*
* Function: Event processing
* Author: LQB
* Time: 2009-1-4
* #include JCore.js
*/
var JEvents = function(){
this.events={};
this.addEvent = function(o){//Add event
if(typeof o == 'string'){/* Pass parameters in the form of strArg1, strArg2...*/
for(var i = 0, a = arguments, v; v = a[i]; i ){
v = v.toString().toLowerCase( );
var enFX = v.indexOf("on")==0 ? v.substr(2) : v;
if(!this.events[enFX]){
this.events[ enFX] = true;
}
}
}else{
JCore.apply(this.events, o,false);
}
};
this.addListener = function(eventName,fn,scope/*,Args……*/){//Add a processing method for the event
if(typeof(eventName)!="string"|| eventName.lenght==0)return;
if(typeof(fn)!="function")return;
eventName = eventName.toString().toLowerCase();
var enFX = eventName.indexOf("on")==0 ? eventName.substr(2) : eventName;
if(!this.events[enFX]){
throw "Error! Event /"" eName "/" doesnt exist."
}
var sp = scope||window;
var callArgs = Array.prototype.slice.call(arguments, 3);//Starting from the 4th parameter
callArgs = typeof(callArgs)!="undefined"?callArgs :[];
var delegate = fn.createDelegate(callArgs,sp);//JCore supports
//Create a mark for the fn method and use
if(!fn.uid) { when deleting an event
var time = new Date();
fn.uid= "" time.getMinutes() time.getSeconds() time.getMilliseconds();
}
//Mark delegate, delete When binding events, use
delegate.uid = getCacheAttName(enFX,fn.uid);
if(typeof(this.events[enFX])!="object")
this.events[enFX] =[];
this.events[enFX].push(delegate);//Add the method to the event list
};
this.removeListener = function(eventName,fn){//Move Except event binding
if(eventName && fn){
eventName = eventName.toString().toLowerCase();
var enFX = eventName.indexOf("on")==0?eventName.substr (2):eventName;
var AttName = getCacheAttName(enFX,fn.uid);
if(typeof(this.events[enFX])=="object"){//This event exists
var functions = this.events[enFX];
for(i=0;i
this.events[enFX].remove(functions[i]);
break;
}
}
}
}
}
this.fireEvent = function(eName,eventArg){//Trigger event
eName = eName.toString().toLowerCase();
var enFX = eName.indexOf("on")==0 ? eName.substr(2) : eName;
var Arg = new Array();
if(typeof(eventArg)!="undefined"){
if(typeof(eventArg)=="array ") Arg=eventArg;
else Arg.push(eventArg);
}
if(typeof(this.events[enFX])=="object"){//This event exists and is added at the same time Event handling method
var functions = this.events[enFX];
for(i=0;i
}
}
}
/*-------------------------- ------------Private method------------------------------------ --*/
var getCacheAttName = function(eventName,fnuid){
return "handle-" eventName "-" fnuid;
}
}
/*------ --------------------------------------------------------The following is Static method, used to handle DOM element events------------------------------------------------ -*/
var JEventsExtendMethod = {
cache : {//Time processing cache, used to mark each event processing method, used when deleting events
eventCache : {},
setCache : function( el,Name,value){
if(typeof(this.eventCache[el])!="object"){
this.eventCache[el]={length :1};
}
this.eventCache[el][Name]=value;
this.eventCache[el].length ;
},
getCache : function(el,Name){
if(typeof(this .eventCache[el]) == "object")
return this.eventCache[el][Name];
else
return null;
},
removeCache : function(el, Name){
if(typeof(this.eventCache[el]) == "object"){
delete this.eventCache[el][Name];//Delete attribute
this.eventCache[el ].length--;
}
if(this.eventCache[el] && this.eventCache[el].length ==1)//Clear
delete this.eventCache[el];
}
},
getCacheAttName : function(eventName,fnuid){
return "handle-" eventName "-" fnuid;
},
bind : function(el,eventName,fn ,scope/*,Args……*/){//Add event handling method for element
if(typeof(el)=="undefined"||el==null)return;
if(typeof(eventName)!="string"| | eventName.lenght==0)return;
if(typeof(fn)!="function")return;
var indexOfon = eventName.toString().toLowerCase().indexOf("on");
var enIE = indexOfon==0?eventName:"on" eventName;
var enFX = indexOfon==0?eventName.substr(2):eventName;
var sp = scope||window;
var callArgs = Array.prototype.slice.call(arguments, 4); //Start from the 5th parameter
callArgs = typeof(callArgs)!="undefined"?callArgs:[];
var delegate = fn.createDelegate(callArgs,sp);//JCore supports
if (el.addEventListener){//Mozilla series, executed in queue order
el.addEventListener(enFX, delegate, false);// The third parameter is related to the triggering method
} else if (el.attachEvent){//Non-Mozilla series, executed in stack order (events added later are executed first)
el.attachEvent(enIE, delegate);
}
//Create a tag for the fn method and use it when deleting the event. " time.getMinutes() time.getSeconds() time.getMilliseconds();
}
if(!el.id){
el.id = JCore.id(el,null);
}
//Mark delegate, use when deleting event bindings
var AttName = this.getCacheAttName(enFX,fn.uid);
this.cache.setCache(el.id,AttName,delegate );
},
unbind : function(el,eventName,fn){//Unbind event for element
if(typeof(el)=="undefined"||el==null) return;
var indexOfon = eventName.toString().toLowerCase().indexOf("on");
var enIE = indexOfon==0?eventName:"on" eventName;
var enFX = indexOfon ==0?eventName.substr(2):eventName;
var AttName = this.getCacheAttName(enFX,fn.uid);
var delegate = this.cache.getCache(el.id,AttName);
if(delegate){
if (el.removeEventListener){//Mozilla series
el.removeEventListener(enFX, delegate, false);
} else if (el.detachEvent){//non Mozilla series
el.detachEvent(enIE, delegate);
}
}
//Delete event cache
this.cache.removeCache(el.id,AttName);
}
}
JCore.apply(JEvents,JEventsExtendMethod);
/*-------------------------------- ---Parameter wrapper for event---------------------------------*/
var JEventWrap = function (event){
this.xtype="EventWrap";
this.data=null;
this.srcElement = null; //The document element where the event occurred
this.button = null; / /[FX:0-left button, 1-middle button, 2-right button][IE:1-left button, 2-right button, 4-middle button] (Only valid for onmousedown, onmouseup, onmousemove)
this. type = null;
this.clientX = 0; //The X coordinate of the mouse pointer relative to the client area or browser window (standard attribute)
this.clientY = 0; //The mouse pointer relative to the client area or browser Y coordinate of the window (standard attribute)
this.offsetX = 0; //X coordinate of the mouse pointer relative to the source element (compatible attribute) (IE)
this.offsetY = 0; //Mouse pointer relative to Y coordinate of the source element (compatibility attribute) (IE)
this.screenX = 0; //X coordinate of the mouse pointer relative to the upper left corner of the user's display (compatibility attribute) (FX)
this.screenY = 0; //The Y coordinate of the mouse pointer relative to the upper left corner of the user's display (compatibility attribute) (FX)
this.altKey = false; //Whether the Alt key
this.ctrlKey = false; //Whether the Ctrl key,
this.shitfKey = false; //Whether the Shift key
this.keyCode = 0;
this.originaEvent = null; //Unwrapped original event object
/*----Construction- ----*/
if(event){
if(event.srcElement){//IE
this.srcElement = event.srcElement;
this.offsetX = event.offsetX;
this.offsetY = event.offsetY;
this.button = event.button;
}
else{
this.srcElement = event.target;
this.offsetX = event. clientX - event.target.offsetLeft;
this.offsetY = event.clientY - event.target.offsetTop;
}
this.type = event.type;
this.altKey = event.altKey ;
this.ctrlKey = event.ctrlKey;
this.shitfKey = event.shitfKey;
this.clientX = event.clientX;
this.clientY = event.clientY;
this. screenX = event.screenX;
this.screenY = event.screenY;
this.keyCode = event.keyCode;
this.originaEvent = event;
}
}
See the previous blog for the JCore.js file:
Object-oriented Javascript core support code

JavaScript's applications in the real world include server-side programming, mobile application development and Internet of Things control: 1. Server-side programming is realized through Node.js, suitable for high concurrent request processing. 2. Mobile application development is carried out through ReactNative and supports cross-platform deployment. 3. Used for IoT device control through Johnny-Five library, suitable for hardware interaction.

I built a functional multi-tenant SaaS application (an EdTech app) with your everyday tech tool and you can do the same. First, what’s a multi-tenant SaaS application? Multi-tenant SaaS applications let you serve multiple customers from a sing

This article demonstrates frontend integration with a backend secured by Permit, building a functional EdTech SaaS application using Next.js. The frontend fetches user permissions to control UI visibility and ensures API requests adhere to role-base

JavaScript is the core language of modern web development and is widely used for its diversity and flexibility. 1) Front-end development: build dynamic web pages and single-page applications through DOM operations and modern frameworks (such as React, Vue.js, Angular). 2) Server-side development: Node.js uses a non-blocking I/O model to handle high concurrency and real-time applications. 3) Mobile and desktop application development: cross-platform development is realized through ReactNative and Electron to improve development efficiency.

The latest trends in JavaScript include the rise of TypeScript, the popularity of modern frameworks and libraries, and the application of WebAssembly. Future prospects cover more powerful type systems, the development of server-side JavaScript, the expansion of artificial intelligence and machine learning, and the potential of IoT and edge computing.

JavaScript is the cornerstone of modern web development, and its main functions include event-driven programming, dynamic content generation and asynchronous programming. 1) Event-driven programming allows web pages to change dynamically according to user operations. 2) Dynamic content generation allows page content to be adjusted according to conditions. 3) Asynchronous programming ensures that the user interface is not blocked. JavaScript is widely used in web interaction, single-page application and server-side development, greatly improving the flexibility of user experience and cross-platform development.

Python is more suitable for data science and machine learning, while JavaScript is more suitable for front-end and full-stack development. 1. Python is known for its concise syntax and rich library ecosystem, and is suitable for data analysis and web development. 2. JavaScript is the core of front-end development. Node.js supports server-side programming and is suitable for full-stack development.

JavaScript does not require installation because it is already built into modern browsers. You just need a text editor and a browser to get started. 1) In the browser environment, run it by embedding the HTML file through tags. 2) In the Node.js environment, after downloading and installing Node.js, run the JavaScript file through the command line.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Notepad++7.3.1
Easy-to-use and free code editor

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.