如何在 JavaScript 中处理 DOM 元素以避免内存泄漏 [英] How to dispose of DOM elements in JavaScript to avoid memory leaks

问题描述

我有一个应用程序，允许用户在没有回发的情况下查看特定案例的详细信息.每次用户从服务器请求数据时，我都会下拉以下标记.

<div><input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE"/>

<div><input type="hidden" name="__EVENTVALIDATION" id="__EVENTVALIDATION"/>

<div id="内部"><!-- 这里的有效信息--!>

</表单>

接下来我将上面的内容和 innerHTML 变成一个新的 DOM 元素，如下所示:

 成功:function(xhtml) {var tr = document.createElement('tr');var td = document.createElement('td');var container = document.createElement('div');obj.parentNode.parentNode.parentNode.insertBefore(tr, obj.parentNode.parentNode.nextSibling);td.appendChild(容器);container.innerHTML = xhtml;tr.appendChild(td);

但是在上面之后，我使用了一些jQuery来删除讨厌的aspnet垃圾

$('form:eq(1)').children().each(功能() {if ($('form:eq(1)').find('div').filter(function() { return $(this).attr('id') == ''; }).remove());});//捕获剩余的孩子var children = $('form:eq(1)').children();//删除表单$('form:eq(1)').remove();//将正确的子元素追加回 DOMparentObj.append(children);

我的问题是 - 在使用 IESieve 时，我注意到没有实际泄漏，但越来越多DOM 元素(因此内存使用).

我可以在客户端改进什么来真正清理这个烂摊子?注意 - IE7/8 都显示了这些结果.

编辑:我终于开始工作并决定写一个简短的博文 带有完整的源代码.

解决方案

棘手的部分是找出哪里仍然存在对违规节点的引用.

您这样做很困难——您将所有标记添加到页面，然后删除您不想要的内容.我会这样做:

var div = document.createElement('div');//(不要将其附加到文档中.)$(div).html(xhtml);var stuffToKeep = $(div).find("form:eq(1)> *").filter(功能() {返回 $(this).attr('id') !== '';});parentObj.append(stuffToKeep);//然后为安全起见，将 DIV 的原始引用归零.div = 空；

这不能保证阻止泄漏，但这是一个好的开始.

I have an application that allows a user to view details on a specific case w/out a postback. Each time a user requests data from the server I pull down the following markup.

<form name="frmAJAX" method="post" action="Default.aspx?id=123456" id="frmAJAX">
<div>
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" />
</div>
<div>
<input type="hidden" name="__EVENTVALIDATION" id="__EVENTVALIDATION" />
</div>
<div id="inner">
<!-- valid info here --!>
</div>
</form>

Next I take the above and innerHTML it to a new DOM element like so:

   success: function(xhtml) {
        var tr = document.createElement('tr');
        var td = document.createElement('td');
        var container = document.createElement('div');

        obj.parentNode.parentNode.parentNode.insertBefore(tr, obj.parentNode.parentNode.nextSibling);

        td.appendChild(container);
        container.innerHTML = xhtml;
        tr.appendChild(td);

but after the above, I use some jQuery to remove the nasty aspnet junk

$('form:eq(1)').children().each(
    function() {
        if ($('form:eq(1)').find('div').filter(function() { return $(this).attr('id') == ''; }).remove());
    }
);

//Capture the remaining children
var children = $('form:eq(1)').children();

// Remove the form
$('form:eq(1)').remove();

// append the correct child element back to the DOM
parentObj.append(children);

My question is this - When using IESieve I notice no actual leaks but an ever growing number of DOM elements (thus memory usage).

What can I improve on in the client-side to actually cleanup this mess? Note- both IE7/8 show these results.

EDIT: I did finally get this working and decided to write a short blog post with complete source code.

解决方案

The tricky part is figuring out where a reference still exists to the offending nodes.

You're doing this the hard way — you're adding all the markup to the page, then removing the stuff you don't want. I'd do it this way instead:

var div = document.createElement('div');
// (Don't append it to the document.)

$(div).html(xhtml);

var stuffToKeep = $(div).find("form:eq(1)> *").filter(
  function() {
    return $(this).attr('id') !== '';
  }
);

parentObj.append(stuffToKeep);

// Then null out the original reference to the DIV to be safe.
div = null;

This isn't guaranteed to stop the leak, but it's a good start.

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