如何优化jQuery tag:contains()选择器?

问题描述 投票:0回答:1

我正在尝试从包含给定单词集的网页中提取所有元素。例如。鉴于我有一个随机单词数组

words = ["sky", "element", "dry", "smooth", "java", "running", "illness", "lake", "soothing", "cardio", "gymnastic"]

并假设所有元素都出现在DOM中。这意味着我需要检查每个可能的标签是否存在。以下是我要搜索的标签。

// 14 essential tags 
items = ["p", "li", "h2", "h3", "h4", "h5", "h6", "b", "small", "td", "span", "strong", "blockquote", "div"] 

我还需要确保单词的空白边界。因此,对于每个单词,我需要在jquery contains()选择器中定义3个检查,如下所示。

tagName:contains('sky '), tagName:contains(' sky'), tagName:contains(' sky ')`

因此,总计上述情况的最终查询使words.length * items.length * 3 14 * 11 * 3 = 462个选择器。这本身就是一个大查询,并且随着单词数组开始增长,我的查询如下所示。

$(p:icontains('ACCESSIBLE '), p:icontains(' ACCESSIBLE'), p:icontains(' ACCESSIBLE '), li:icontains('ACCESSIBLE '), li:icontains(' ACCESSIBLE'), li:icontains(' ACCESSIBLE '), h3:icontains('ACCESSIBLE '), h3:icontains(' ACCESSIBLE'), h3:icontains(' ACCESSIBLE '), h4:icontains('ACCESSIBLE '), h4:icontains(' ACCESSIBLE'), h4:icontains(' ACCESSIBLE '), h5:icontains('ACCESSIBLE '), h5:icontains(' ACCESSIBLE'), h5:icontains(' ACCESSIBLE '), b:icontains('ACCESSIBLE '), b:icontains(' ACCESSIBLE'), b:icontains(' ACCESSIBLE '), td:icontains('ACCESSIBLE '), td:icontains(' ACCESSIBLE'), td:icontains(' ACCESSIBLE '), span:icontains('ACCESSIBLE '), span:icontains(' ACCESSIBLE'), span:icontains(' ACCESSIBLE '), strong:icontains('ACCESSIBLE '), strong:icontains(' ACCESSIBLE'), strong:icontains(' ACCESSIBLE '), div:icontains('ACCESSIBLE '), div:icontains(' ACCESSIBLE'), div:icontains(' ACCESSIBLE ')p:icontains('ADDRESS '), p:icontains(' ADDRESS'), p:icontains(' ADDRESS '), li:icontains('ADDRESS '), li:icontains(' ADDRESS'), li:icontains(' ADDRESS '), h3:icontains('ADDRESS '), h3:icontains(' ADDRESS'), h3:icontains(' ADDRESS '), h4:icontains('ADDRESS '), h4:icontains(' ADDRESS'), h4:icontains(' ADDRESS '), h5:icontains('ADDRESS '), h5:icontains(' ADDRESS'), h5:icontains(' ADDRESS '), b:icontains('ADDRESS '), b:icontains(' ADDRESS'), b:icontains(' ADDRESS '), td:icontains('ADDRESS '), td:icontains(' ADDRESS'), td:icontains(' ADDRESS '), span:icontains('ADDRESS '), span:icontains(' ADDRESS'), span:icontains(' ADDRESS '), strong:icontains('ADDRESS '), strong:icontains(' ADDRESS'), strong:icontains(' ADDRESS '), div:icontains('ADDRESS '), div:icontains(' ADDRESS'), div:icontains(' ADDRESS ')p:icontains('ANTIEMETICS '), p:icontains(' ANTIEMETICS'), p:icontains(' ANTIEMETICS '), li:icontains('ANTIEMETICS '), li:icontains(' ANTIEMETICS'), li:icontains(' ANTIEMETICS '), h3:icontains('ANTIEMETICS '), h3:icontains(' ANTIEMETICS'), h3:icontains(' ANTIEMETICS '), h4:icontains('ANTIEMETICS '), h4:icontains(' ANTIEMETICS'), h4:icontains(' ANTIEMETICS '), h5:icontains('ANTIEMETICS '), h5:icontains(' ANTIEMETICS'), h5:icontains(' ANTIEMETICS '), b:icontains('ANTIEMETICS '), b:icontains(' ANTIEMETICS'), b:icontains(' ANTIEMETICS '), td:icontains('ANTIEMETICS '), td:icontains(' ANTIEMETICS'), td:icontains(' ANTIEMETICS '), span:icontains('ANTIEMETICS '), span:icontains(' ANTIEMETICS'), span:icontains(' ANTIEMETICS '), strong:icontains('ANTIEMETICS '), strong:icontains(' ANTIEMETICS'), strong:icontains(' ANTIEMETICS '), div:icontains('ANTIEMETICS '), div:icontains(' ANTIEMETICS'), div:icontains(' ANTIEMETICS ')p:icontains('BRAND '), p:icontains(' BRAND'), p:icontains(' BRAND '), li:icontains('BRAND '), li:icontains(' BRAND'), li:icontains(' BRAND '), h3:icontains('BRAND '), h3:icontains(' BRAND'), h3:icontains(' BRAND '), h4:icontains('BRAND '), h4:icontains(' BRAND'), h4:icontains(' BRAND '), h5:icontains('BRAND '), h5:icontains(' BRAND'), h5:icontains(' BRAND '), b:icontains('BRAND '), b:icontains(' BRAND'), b:icontains(' BRAND '), td:icontains('BRAND '), td:icontains(' BRAND'), td:icontains(' BRAND '), span:icontains('BRAND '), span:icontains(' BRAND'), span:icontains(' BRAND '), strong:icontains('BRAND '), strong:icontains(' BRAND'), strong:icontains(' BRAND '), div:icontains('BRAND '), div:icontains(' BRAND'), div:icontains(' BRAND ')p:icontains('CAPABLE '), p:icontains(' CAPABLE'), p:icontains(' CAPABLE '), li:icontains('CAPABLE '), li:icontains(' CAPABLE'), li:icontains(' CAPABLE '), h3:icontains('CAPABLE '), h3:icontains(' CAPABLE'), h3:icontains(' CAPABLE '), h4:icontains('CAPABLE '), h4:icontains(' CAPABLE'), h4:icontains(' CAPABLE '), h5:icontains('CAPABLE '), h5:icontains(' CAPABLE'), h5:icontains(' CAPABLE '), b:icontains('CAPABLE '), b:icontains(' CAPABLE'), b:icontains(' CAPABLE '), td:icontains('CAPABLE '), td:icontains(' CAPABLE'), td:icontains(' CAPABLE '), span:icontains('CAPABLE '), span:icontains(' CAPABLE'), span:icontains(' CAPABLE '), strong:icontains('CAPABLE '), strong:icontains(' CAPABLE'), strong:icontains(' CAPABLE '), div:icontains('CAPABLE '), div:icontains(' CAPABLE'), div:icontains(' CAPABLE ')p:icontains('COMMAND '), p:icontains(' COMMAND'), p:icontains(' COMMAND '), li:icontains('COMMAND '), li:icontains(' COMMAND'), li:icontains(' COMMAND '), h3:icontains('COMMAND '), h3:icontains(' COMMAND'), h3:icontains(' COMMAND '), h4:icontains('COMMAND '), h4:icontains(' COMMAND'), h4:icontains(' COMMAND '), h5:icontains('COMMAND '), h5:icontains(' COMMAND'), h5:icontains(' COMMAND '), b:icontains('COMMAND '), b:icontains(' COMMAND'), b:icontains(' COMMAND '), td:icontains('COMMAND '), td:icontains(' COMMAND'), td:icontains(' COMMAND '), span:icontains('COMMAND '), span:icontains(' COMMAND'), span:icontains(' COMMAND '), strong:icontains('COMMAND '), strong:icontains(' COMMAND'), strong:icontains(' COMMAND '), div:icontains('COMMAND '), div:icontains(' COMMAND'), div:icontains(' COMMAND ')p:icontains('CONFLUENCE ') ....

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具有87Kb选择器的查询,在页面上执行将花费将近30-40秒。有什么方法可以对其进行优化。在进行查询之前,我已经消除了页面中不存在的标签。

编辑:之所以无法使用正则表达式进行整页文本解析,是因为我需要在解析后用一些HTML替换那些匹配的单词,这类似于在页面上注入一些HTML来突出显示这些单词。如果我做正则表达式,我将失去对HTML元素及其位置的控制。同样,正则表达式替换不会保证文本节点。它还替换了写在标题属性和其他属性(如果存在)中的单词。

javascript jquery performance dom optimization
1个回答
1
投票

相反,为什么不只使用整个页面的html,而对单词数组使用正则表达式呢?

测试HTML:

<div id='container'>
<p>Chess</p>
<span>Chess and Checkers</span>
<h1> Chess and Checkers</h1>
</div>

Javascript:

$("document").ready(function() {
    var html = $("#container").html();
    var words = ["Chess", "checkers"];

    $.each(words, function() {
      var phrase = this;    
      html = html.replace(new RegExp(phrase, "gim"), "foo");
    });
    $("#container").html(html);
});

输出:

foo

foo和foo

foo和foo

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