通過HTML標記進行XPath搜索

下面的HTML顯示第三個搜索（搜索「Practice Guidelines Professional」）不起作用，因爲文本「Practice Guidelines」位於<strong></strong>標記之間......是否可以實現XPath搜索繞過文本之間的HTML標籤？通過HTML標記進行XPath搜索

<html> 
<head> 
<meta http-equiv="X-UA-Compatible" content="chrome=1"> 
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 
<meta name="apple-mobile-web-app-capable" content="yes"> 
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" /> 
<title>Xpath Test</title> 

<script type="text/javascript"> 
var search = function (button) { 
    var searchTxt = button.value; 
    var xpath = '//*[contains(translate(text(),\'ABCDEFGHIJKLMNOPQRSTUVWXYZ\', \'abcdefghijklmnopqrstuvwxyz\'), \'' + searchTxt.toLowerCase() + '\')]'; 
    var nodes = null; 

    if (document.evaluate) { 
     nodes = document.evaluate(
      xpath, 
      document, 
      null, 
      XPathResult.ORDERED_NODE_ITERATOR_TYPE, 
      null 
     ); 

     var node = nodes.iterateNext(); 
     if (node) { 
      while (node) { 
       var nodeXpath = createXPathFromElement(node); 
       alert("Found!!!\n xpath: " + nodeXpath); 
       node = nodes.iterateNext(); 
      } 
     } else { 
      alert("No results found."); 
     } 
    } else { 
     alert("Your browser does not support the evaluate method!"); 
    } 
    } 

    function createXPathFromElement(elm) { 
    var allNodes = document.getElementsByTagName('*'); 
    for (segs = []; elm && elm.nodeType == 1; elm = elm.parentNode) 
    { 
     for (i = 1, sib = elm.previousSibling; sib; sib = sib.previousSibling) { 
      if (sib.localName == elm.localName) i++; 
     }; 
     segs.unshift(elm.localName.toLowerCase() + '[' + i + ']'); 
    }; 
    return segs.length ? '//' + segs.join('//') : null; 
    } 
</script> 
</head> 

<body> 
<table> 
    <tr> 
     <td> 
      <p>&#160;</p><h3><strong><span class="color-1">PRINCIPLES OF PATIENT CARE</span></strong></h3><p class="noindent"><strong><span class="color-1">Evidence-Based Medicine</span></strong> Evidence-based medicine refers to the concept that clinical decisions are formally supported by data, preferably data that are derived from prospectively designed, randomized, controlled clinical trials. This is in sharp contrast to anecdotal experience, which may often be biased. Unless they are attuned to the importance of using larger, more objective studies for making decisions, even the most experienced physicians can be influenced by recent encounters with selected patients. Evidence-based medicine has become an increasingly important part of the routine practice of medicine and has led to the publication of a number of practice guidelines.</p> 
      <p>&#160;</p><p class="noindent"><strong><span class="color-1">Practice Guidelines</span></strong> Professional organizations and government agencies are developing formal clinical-practice guidelines to aid physicians and other caregivers in making diagnostic and therapeutic decisions that are evidence-based, cost-effective, and most appropriate to a particular patient and clinical situation. As the evidence base of medicine increases, guidelines can provide a useful framework for managing patients with particular diagnoses or symptoms. They can protect patients—particularly those with inadequate health care benefits—from receiving substandard care. Guidelines can also protect conscientious caregivers from inappropriate charges of malpractice and society from the excessive costs associated with the overuse of medical resources. There are, however, caveats associated with clinical practice guidelines since they tend to oversimplify the complexities of medicine. Furthermore, groups with differing perspectives may develop divergent recommendations regarding issues as basic as the need for periodic sigmoidoscopy in middle-aged persons. Finally, guidelines do not—and cannot be expected to—account for the uniqueness of each individual and his or her illness. The physician’s challenge is to integrate into clinical practice the useful recommendations offered by experts without accepting them blindly or being inappropriately constrained by them.</p>    
     </td> 
    </tr> 
    <tr> 
     <td> 
      Search for <input type="button" onclick="search(this)" value="Practice Guidelines" /> Success. 
     </td> 
    </tr> 
    <tr> 
     <td> 
      Search for <input type="button" onclick="search(this)" value="Professional" /> Success. 
     </td> 
    </tr> 
    <tr> 
     <td> 
      Search for <input type="button" onclick="search(this)" value="Practice Guidelines Professional" /> No result since text 'Practice Guidelines' is inside &lt;strong&gt;&lt;strong/&gt;, and 'Professional' is out side.  
     </td> 
    </tr> 
</table> 
</body> 
</html>

來源

2011-07-25 Jagadeesan

是的。您可以使用normalize-space()。 （線爲了便於閱讀起見）

var xpath = " 
    //*[ 
    contains(
     translate(
     normalize-space(.), 
     'ABCDEFGHIJKLMNOPQRSTUVWXYZ', 
     'abcdefghijklmnopqrstuvwxyz' 
    ), 
     normalize-space('" + searchTxt.toLowerCase() + "') 
    ) 
    ] 
";

注意，這會發現，包含相應的文本，直到幷包括所述<html>元素節點的整個層次。我想，你會對「最深層嵌套」節點感興趣。

另請注意，您可能希望從searchTxt中刪除單引號，因爲它們會破壞XPath表達式。

來源

2011-07-25 06:38:02 Tomalak

感謝您的幫助。 – Jagadeesan

可能還有一個遞歸方法，它查看根元素的textContent/innerHTML以查看是否找到匹配項。如果是這樣，請沿着與孩子相匹配的firstChild節點走下去，直到匹配失敗，此時找到包含文本的元素。

還應該適用於與文本的多個匹配。

XPath可能會更快，但可能不會被支持（雖然它似乎在所有的現代瀏覽器上）。

來源

2011-07-25 07:27:01 RobG

謝謝...... :) – Jagadeesan

通過HTML標記進行XPath搜索

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