我想在html中添加一些div或input时执行一个函数。这种情况是否可能?
例如,当添加文本输入框时,应该调用该函数。
我想在html中添加一些div或input时执行一个函数。这种情况是否可能?
例如,当添加文本输入框时,应该调用该函数。
(IE11+, FF, Webkit)
使用MutationObserver, 并在必要时退回到已弃用的Mutation事件:
(以下示例仅针对追加或删除节点的DOM更改)
var observeDOM = (function(){
var MutationObserver = window.MutationObserver || window.WebKitMutationObserver;
return function( obj, callback ){
if( !obj || obj.nodeType !== 1 ) return;
if( MutationObserver ){
// define a new observer
var mutationObserver = new MutationObserver(callback)
// have the observer observe for changes in children
mutationObserver.observe( obj, { childList:true, subtree:true })
return mutationObserver
}
// browser support fallback
else if( window.addEventListener ){
obj.addEventListener('DOMNodeInserted', callback, false)
obj.addEventListener('DOMNodeRemoved', callback, false)
}
}
})()
//------------< DEMO BELOW >----------------
// add item
var itemHTML = "<li><button>list item (click to delete)</button></li>",
listElm = document.querySelector('ol');
document.querySelector('body > button').onclick = function(e){
listElm.insertAdjacentHTML("beforeend", itemHTML);
}
// delete item
listElm.onclick = function(e){
if( e.target.nodeName == "BUTTON" )
e.target.parentNode.parentNode.removeChild(e.target.parentNode);
}
// Observe a specific DOM element:
observeDOM( listElm, function(m){
var addedNodes = [], removedNodes = [];
m.forEach(record => record.addedNodes.length & addedNodes.push(...record.addedNodes))
m.forEach(record => record.removedNodes.length & removedNodes.push(...record.removedNodes))
console.clear();
console.log('Added:', addedNodes, 'Removed:', removedNodes);
});
// Insert 3 DOM nodes at once after 3 seconds
setTimeout(function(){
listElm.removeChild(listElm.lastElementChild);
listElm.insertAdjacentHTML("beforeend", Array(4).join(itemHTML));
}, 3000);
<button>Add Item</button>
<ol>
<li><button>list item (click to delete)</button></li>
<li><button>list item (click to delete)</button></li>
<li><button>list item (click to delete)</button></li>
<li><button>list item (click to delete)</button></li>
<li><em>…More will be added after 3 seconds…</em></li>
</ol>
mutations, observer
参数传递给回调函数以获得更多控制。 - A1rPun!obj.nodeType === 1
。它只是检查 nodeType 是否为元素,所以你可以使用 obj.nodeType !== 1
。 - stldougobserver.disconnect();
,请参阅文档https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver。 - VadorequestMutationObserver
:Chrome18+,Firefox14+,IE11+,Safari6+
如果您需要支持旧版本浏览器,则可以尝试退回到其他方法,例如下面这个五年前的答案中提到的方法。那里有些棘手。祝好运 :)
是否有其他人正在更改文档?因为如果您完全控制更改,您只需要创建自己的domChanged
API - 使用函数或自定义事件 - 并在修改内容时触发/调用它。
DOM级别2有变异事件类型,但较早版本的IE不支持它。请注意,变异事件在DOM3事件规范中已弃用,并且具有性能惩罚。
您可以尝试使用IE中的onpropertychange
来模拟变异事件(如果其中一个不可用,则退回到粗暴的方法)。
对于完整的 domChange,使用时间间隔可能会过度消耗资源。想象一下,您需要存储整个文档的当前状态,并检查每个元素的每个属性是否相同。
也许如果您只对元素及其顺序感兴趣(如您在问题中提到的),则getElementsByTagName("*")
可以起作用。这将自动触发,如果您添加元素,删除元素,替换元素或更改文档的结构。
我写了一个概念验证:
(function (window) {
var last = +new Date();
var delay = 100; // default delay
// Manage event queue
var stack = [];
function callback() {
var now = +new Date();
if (now - last > delay) {
for (var i = 0; i < stack.length; i++) {
stack[i]();
}
last = now;
}
}
// Public interface
var onDomChange = function (fn, newdelay) {
if (newdelay) delay = newdelay;
stack.push(fn);
};
// Naive approach for compatibility
function naive() {
var last = document.getElementsByTagName('*');
var lastlen = last.length;
var timer = setTimeout(function check() {
// get current state of the document
var current = document.getElementsByTagName('*');
var len = current.length;
// if the length is different
// it's fairly obvious
if (len != lastlen) {
// just make sure the loop finishes early
last = [];
}
// go check every element in order
for (var i = 0; i < len; i++) {
if (current[i] !== last[i]) {
callback();
last = current;
lastlen = len;
break;
}
}
// over, and over, and over again
setTimeout(check, delay);
}, delay);
}
//
// Check for mutation events support
//
var support = {};
var el = document.documentElement;
var remain = 3;
// callback for the tests
function decide() {
if (support.DOMNodeInserted) {
window.addEventListener("DOMContentLoaded", function () {
if (support.DOMSubtreeModified) { // for FF 3+, Chrome
el.addEventListener('DOMSubtreeModified', callback, false);
} else { // for FF 2, Safari, Opera 9.6+
el.addEventListener('DOMNodeInserted', callback, false);
el.addEventListener('DOMNodeRemoved', callback, false);
}
}, false);
} else if (document.onpropertychange) { // for IE 5.5+
document.onpropertychange = callback;
} else { // fallback
naive();
}
}
// checks a particular event
function test(event) {
el.addEventListener(event, function fn() {
support[event] = true;
el.removeEventListener(event, fn, false);
if (--remain === 0) decide();
}, false);
}
// attach test events
if (window.addEventListener) {
test('DOMSubtreeModified');
test('DOMNodeInserted');
test('DOMNodeRemoved');
} else {
decide();
}
// do the dummy test
var dummy = document.createElement("div");
el.appendChild(dummy);
el.removeChild(dummy);
// expose
window.onDomChange = onDomChange;
})(window);
用法:
onDomChange(function(){
alert("The Times They Are a-Changin'");
});
这适用于IE 5.5+、FF 2+、Chrome、Safari 3+和Opera 9.6+
(function(window){...}(window))
中将window传递给window是没有意义的。如果意图是安全地获取全局/窗口对象,则应传递this:(function(window){...}(this))
,因为在全局代码中,this始终指向全局/窗口对象。 - RobG// Select the node that will be observed for mutations
var targetNode = document.getElementById('some-id');
// Options for the observer (which mutations to observe)
var config = { attributes: true, childList: true };
// Callback function to execute when mutations are observed
var callback = function(mutationsList) {
for(var mutation of mutationsList) {
if (mutation.type == 'childList') {
console.log('A child node has been added or removed.');
}
else if (mutation.type == 'attributes') {
console.log('The ' + mutation.attributeName + ' attribute was modified.');
}
}
};
// Create an observer instance linked to the callback function
var observer = new MutationObserver(callback);
// Start observing the target node for configured mutations
observer.observe(targetNode, config);
// Later, you can stop observing
observer.disconnect();
浏览器支持:Chrome 18+,Firefox 14+,IE 11+,Safari 6+
我最近编写了一个插件,可以完全实现这一点-jquery.initialize。
(NPM链接-不同的NPM/GitHub用户名,同一作者)
您可以像使用.each
函数一样使用它
$(".some-element").initialize( function(){
$(this).css("color", "blue");
});
.each
不同的地方是-它接受您的选择器,例如 .some-element
并等待将来具有此选择器的新元素,如果添加了这样的元素,它也将被初始化。$("<div/>").addClass('some-element').appendTo("body"); //new element will have blue color!
.detach()
掉它,再重新添加,它将不会再次被初始化。$("<div/>").addClass('some-element').appendTo("body").detach()
.appendTo(".some-container");
//initialized only once
MutationObserver = window.MutationObserver || window.WebKitMutationObserver;
var observer = new MutationObserver(function(mutations, observer) {
// fired when a mutation occurs
console.log(mutations, observer);
// ...
});
// define what element should be observed by the observer
// and what types of mutations trigger the callback
observer.observe(document, {
subtree: true,
attributes: true
//...
});
observer.disconnect()
。 - Soley或者您可以简单地创建自己的活动,让它在任何地方运行
$("body").on("domChanged", function () {
//dom is changed
});
$(".button").click(function () {
//do some change
$("button").append("<span>i am the new change</span>");
//fire event
$("body").trigger("domChanged");
});
使用MutationObserver接口,如Gabriele Romanato的博客中所示
Chrome 18+,Firefox 14+,IE 11+,Safari 6+
// The node to be monitored
var target = $( "#content" )[0];
// Create an observer instance
var observer = new MutationObserver(function( mutations ) {
mutations.forEach(function( mutation ) {
var newNodes = mutation.addedNodes; // DOM NodeList
if( newNodes !== null ) { // If there are new nodes added
var $nodes = $( newNodes ); // jQuery set
$nodes.each(function() {
var $node = $( this );
if( $node.hasClass( "message" ) ) {
// do something
}
});
}
});
});
// Configuration of the observer:
var config = {
attributes: true,
childList: true,
characterData: true
};
// Pass in the target node, as well as the observer options
observer.observe(target, config);
// Later, you can stop observing
observer.disconnect();
8年之后,我用 MutationObserver
和 RxJS
来解决这个问题。
observeDOMChange(document.querySelector('#dom-changes-here'))
.subscribe(val => log('DOM-change detected'));
CustomEvent
,并监听事件以执行以下具有高效特性的用户逻辑;
import { fromEvent, timer} from 'rxjs';
import { debounceTime, takeUntil, tap } from 'rxjs/operators';
function observeDOMChange(el, options={}) {
options = Object.assign({debounce: 100, expires: 2000}, options);
const observer = new MutationObserver(list => {
el.dispatchEvent(new CustomEvent('dom-change', {detail: list}));
});
observer.observe(el, {attributes: false, childList: true, subtree: true });
let pipeFn;
if (options.expires) {
setTimeout(_ => observer.disconnect(), options.expires);
pipeFn = takeUntil(timer(options.expires));
} else {
pipeFn = tap(_ => _);
}
return fromEvent(el, 'dom-change')
.pipe(pipeFn, debounceTime(options.debounce));
}
这个问题可以考虑扩展一个 jQuery 插件来解决。
(function () {
var ev = new $.Event('remove'),
orig = $.fn.remove;
var evap = new $.Event('append'),
origap = $.fn.append;
$.fn.remove = function () {
$(this).trigger(ev);
return orig.apply(this, arguments);
}
$.fn.append = function () {
$(this).trigger(evap);
return origap.apply(this, arguments);
}
})();
$(document).on('append', function (e) { /*write your logic here*/ });
$(document).on('remove', function (e) { /*write your logic here*/ });
发现这个问题,因此在2022年更新了解决方案。
我们看到不同的解决方案,大多数都涉及MutationObserver
。
如果有人想记录DOM更改并将其存储以供稍后重放,他们可以使用rrweb
编辑:
添加示例,以下是提示:
让我们以CDN为例,记录DOM更改事件:
步骤1:只需在<HTML><head>
标签中包含以下脚本标记
<script src="https://cdn.jsdelivr.net/npm/rrweb@2.0.0-alpha.2/dist/rrweb-all.js" crossorigin="anonymous"></script>
步骤2:并将以下代码添加到您的代码中,以捕获rrweb生成的事件。
<script>
var events = [];
rrweb.record({
emit(event) {
events.push(event);
// you can store this event anywhere and you can replay them later. ex: some JSON file, or DB
}
});
</script>
这个例子主要是记录任何Web应用程序的事件。
如果想了解并详细了解(如何记录/重放),请阅读rrweb文档。
重放器示例:
这是为了调试,但在此添加以便任何人都可以检查重放的一面: