如何通过DOMAttrModified检测类更改 [英] How to detect class changing by DOMAttrModified

问题描述

我需要检测一些类更改，我用于这个DOMAttrModified，但是有什么问题，什么？

I need to detect some class changing, i use for this DOMAttrModified, but something is wrong, what?

var first_img = $('body').find('li:first').find('img');

first_img.on('DOMAttrModified',function(e){
    if (e.attrName === 'class') {
        if ($(this).hasClass('current-image')) {
            $(this).removeClass().addClass('previous-image');
        }
        console.log('log');
    }
});

Thx for advice。

Thx for advice.

推荐答案

现在的问题是，一个 attrName 属性不是jQuery事件对象的一部分...您需要使用 e.originalEvent.attrName 。这是一个例子：

The immediate problem is that a attrName property isn't part of jQuery's event's object...you need to use e.originalEvent.attrName. Here's an example of it working:

var first_img = $("body").find("div").first();

first_img.on("DOMAttrModified", function (e) {
    if (e.originalEvent.attrName === "class") {
        console.log("##DOMAttrModified, class changed");
        if ($(this).hasClass("current-image")) {
            console.log("##Element has 'current-image' class, changing");
            $(this).removeClass().addClass("previous-image");
        }
    }
});

setTimeout(function () {
    first_img.addClass("current-image");
}, 1000);

演示： http://jsfiddle.net/R5rTy/1/

setTimeout 是模拟事件随机发生的。

The setTimeout is to simulate the event randomly happening.

显然，所有浏览器都不支持 DOMAttrModified 事件 - http://help.dottoro.com/ljfvvdnm.php#additionalEvents

Apparently, the DOMAttrModified event is not supported in all browsers - http://help.dottoro.com/ljfvvdnm.php#additionalEvents

更新：

使用较新的 MutationObserver ，下面显示了两种想法的使用：

Using the newer MutationObserver, the following shows the use of both ideas:

var firstImg, observerConfig, firstImgObserver;

firstImg = $("body").find("div").first();
observerConfig = {
    attributes: true,
    childList: true,
    characterData: true
};
firstImgObserver = new MutationObserver(function (mutations) {
    mutations.forEach(function (mutation) {
        var newVal = $(mutation.target).prop(mutation.attributeName);
        if (mutation.attributeName === "class") {
            console.log("MutationObserver class changed to", newVal);
        } else if (mutation.attributeName === "id") {
            console.log("MutationObserver id changed to", newVal);
        }
    });
});

firstImgObserver.observe(firstImg[0], observerConfig);
// later, you can stop observing
//observer.disconnect();

firstImg.on("DOMAttrModified", function (e) {
    var newVal = $(this).prop(e.originalEvent.attrName);
    console.log("DOMAttrModified", e.originalEvent.attrName, "changed to", newVal);
});

setTimeout(function () {
    firstImg.addClass("previous-image").addClass("fdsa");
}, 1000);

演示： http://jsfiddle.net/ybGCF/

参考：

• https://developer.mozilla.org/en-US/ docs / Web / API / MutationObserver

• https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver

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