为什么无法通过ID（无iframe）访问此动态加载的DOM元素？ [英] Why can't I access this dynamically loaded DOM element by ID (no iframes)?

问题描述

我正在使用允许嵌入JavaScript内容（Qualtrics）的外部网站。 Qualtrics动态加载一些控制器。当我通过Chrome网络面板测试访问这些控制器时，在完全加载后，我可以在Elements窗口中看到加载的控制器，代表当前的DOM。但是，我不能通过id，通过jQuery或通过document.getElementById访问这些元素。

I am working with an external site that allows embedded javascript content (Qualtrics). Qualtrics dynamically loads some controllers. When I test accessing these controllers via the Chrome web panel, after they have fully loaded, I can see the loaded controllers in the Elements window which represents the current DOM. However, I cannot access these elements by id, either with jQuery or via document.getElementById.

其中一个控制器的id QID12〜14 〜handle 。在元素DOM浏览器中，我看到标签：

One of the controllers has the id QID12~14~handle. In the Elements DOM browser, I see the tag:

<div id="QID12~14~handle" class="handle selected" style="left: 122px;"></div>

当我查看页面的源代码时，我发现它们是动态加载并通过脚本插入页面标签：

When I view the page's source, I see they are dynamically loading and inserted into the page via a script tag:

<div class='QuestionBody BorderColor'>
    <div class='horizontalbar ChoiceStructure RtlOverride'></div>
    <div id='debug'></div>

    <!-- This has to be called after the html it references. Thats why its down here -->

    <script type='text/javascript'>
        QModules.loadExternalModule('../WRQualtricsShared/JavaScript/CSBar/slider.51487.js', function () {
            (function () {
                CS_QID15 = new CSBar('0', '100', '10', 'QID15', '');
                if (CS_QID15.loaded) {
                    CS_QID15.setDecimals(0);
                    if (CS_QID15.snapToGrid) {
                        CS_QID15.makeSlider('QID15~1');
                        CS_QID15.makeSlider('QID15~2');

                        CS_QID15.setStartPositions({"1": 0, "2": 0, "3": 0.64599483204134});
                    }
                    else {
                        CS_QID15.makeSlider('QID15~1');
                        CS_QID15.makeSlider('QID15~2');

                        CS_QID15.setStartPositions({"1": 0, "2": 0, "3": 0.64599483204134});
                    }
                }
            }).delay(); //if ie is waiting for something and this loads too fast it breaks. the defer fixes a very esoteric bug.
                        });
    </script>

    <div class='clear zero'></div>
</div>

页面未使用iFrames。如果我在当前DOM中看到一个ID，为什么我不能通过它的id来访问它，因为它目前存在于DOM？

The page is not using iFrames. If I see an id in the current DOM, why can't I access it by it's id as it currently exists in the DOM?

如果我调用 jQuery（。handle），我看到这个元素：

If I call jQuery(".handle"), I see this element:

[
  <div id=​"QID12~14~handle" class=​"handle selected" style=​"left:​ 122px;​">​</div>​, 
  <div id=​"QID15~1~handle" class=​"handle selected" style=​"left:​ 0px;​">​</div>​, 
  <div id=​"QID15~2~handle" class=​"handle selected" style=​"left:​ 0px;​">​</div>​
]

什么可能阻止我通过id访问这些元素？

What could prevent me from accessing these elements by id?

推荐答案

QID12〜14〜handle 不是有效的选择器（虽然它是一个有效的 id 属性） code>〜，它们是兄弟选择器。您可以使用id属性本身来解决这个问题：

QID12~14~handle is not a valid selector (although it is a valid id attribute) because of the ~, which are sibling selectors. You can get around this using the id attribute itself:

[id='QID12~14~handle']

或者，您可以使用反斜杠转义选择器（这也适用于 querySelector ）：

Or you can escape the selectors with backslashes (this will also work for querySelector):

QID12\\~14\\~handle

您还可能需要＃来根据您的API指示ID选择器使用。

You may also need # to indicate the ID selector depending upon the API you are working with.

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