查找DomNode/Xpath子元素的索引位置 [英] Find index position of a DomNode/Xpath Child Element

问题描述

我正在使用xpath表达式来确定DOM树中的某个div类(感谢VolkerK！).

I am using an xpath expression to determine a certain div-class in my DOM tree (thanks to VolkerK!).

foreach($xpath->query('//div[@class="posts" and div[@class="foo"]]') as $node)
    $html['content'] = $node->textContent;
    //$html['node-position'] = $node->position(); // (global) index position of the child 'foo'
}

最终，我需要知道我的孩子'foo'在哪个(全局)索引位置，因为以后我想用jQuery替换它: eq()或nth-child().

Eventually I need to know which (global) index position my child 'foo' has, because I want to replace it with jQuery later: eq() or nth-child().

有办法吗?

我正在跟踪我的另一个有关选择正确元素的问题(

I am following up on another Question of mine about selecting the right element (XPath/Domdocument check for child by class name).

谢谢！

更新:

UPDATE:

我发现使用:

$html['node-position'] = $node->getNodePath() 

实际上以父节点的xpath语法(/html/body/div [3])给出了路径和元素编号，但是如何为子div'foo'提供路径和元素编号?

actually gives me the path and the element number in xpath syntax (/html/body/div[3]) of the parent node, but how can it for the child div 'foo'?

推荐答案

用于查找给定元素x 的位置"的XPath方法(其中，位置被定义为表示索引的索引) XML文档中所有x元素的顺序(按文档顺序)中的元素x是:

The XPath way to find the "position" of a given element x (where position is defined to mean the index of that element x in the sequence (in document order) of all x elements in the XML document) is:

count(preceding::x) + count(ancestor-or-self::x)

当此XPath表达式以元素x作为当前节点(初始上下文节点)进行求值时，将产生如此定义的位置".

When this XPath expression is evaluating with the element x as the current node (initial context node), the so defined "position" is produced.

基于XSLT的验证:

让我们拥有这个XML文档:

Let's have this XML document:

<t>
    <d/>
    <emp/>
    <d>
        <emp/>
        <emp/>
        <emp/>
    </d>
    <d/>
</t>

此转换:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:variable name="v3rdEmp" select="/*/d/emp[2]"/>

 <xsl:template match="/">
  <xsl:value-of select=
   "count($v3rdEmp/preceding::emp)
   +
    count($v3rdEmp/ancestor-or-self::emp) "/>
 </xsl:template>
</xsl:stylesheet>

使用文档中的第3个emp元素作为初始上下文节点，计算以上XPath表达式.表达式中的x现在已替换为我们想要的元素名称-emp.然后输出表达式求值的结果-我们看到这是想要的正确结果:

evaluates the above XPath expression using the 3rd emp element in the document as the initial context node. The x in the expression is now substituted by our wanted element name -- emp. Then the result from the expression evaluation is output -- we see that this is the wanted, correct result:

3

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