Symfony2 - DomCrawler - 通过正则表达式中的相邻内容获取元素的内容

Question

我有这个 xml:

<Item id="3" idLevel="3">
    <Label qualifier="Usual">
        <LabelText language="ALL">BE01</LabelText>
    </Label>
    <Label qualifier="Usual">
        <LabelText language="EN">R&#xc9;GION DE BRUXELLES-CAPITALE / BRUSSELS HOOFDSTEDELIJK GEWEST</LabelText>
    </Label>
</Item>
<Item id="4" idLevel="3">
    <Label qualifier="Usual">
        <LabelText language="ALL">BE001</LabelText>
    </Label>
    <Label qualifier="Usual">
        <LabelText language="EN">VLAAMS GEWEST</LabelText>
    </Label>
</Item>
<Item id="123" idLevel="3">
    <Label qualifier="Usual">
        <LabelText language="ALL">RO001</LabelText>
    </Label>
    <Label qualifier="Usual">
        <LabelText language="EN">MACROREGIUNEA DOI</LabelText>
    </Label>
</Item>

我想获取 <LabelText language="EN"> 的值，其中邻居 <LabelText language="ALL"> 以 "BE" 开头，后面有 3 个数字。

在这种情况下，我会得到第二个 xml 元素的值，例如：VLAAMS GEWEST

我知道如何以丑陋的方式处理它，但我相信应该有更灵活和优雅的方式来做到这一点：

$crawler = new Crawler();
$crawler->addXmlContent($xml);
$crawler = $crawler->filterXPath('//Item[@idLevel="3"]');

foreach ($crawler as $domElement) {
    // here I check if inside element's neighbour has value of "BE" and three numbers after with regex
}

有没有办法用 DomCrawler 来处理它而不是迭代所有元素并检查每个元素？

Answer 1

您可以使用单个 XPath 表达式来获取所需的文本：

//Item[@idLevel="3"]/Label[string-length(preceding-sibling::Label/LabelText/text()) = 5 and starts-with(preceding-sibling::Label/LabelText/text(), "BE") and number(substring(preceding-sibling::Label/LabelText/text(), 3)) = number(substring(preceding-sibling::Label/LabelText/text(), 3))]/LabelText[@language="EN"]/text()

分解：

//Item[@idLevel="3"] - 获取具有 idLevel 属性且值为 3

Item

/Label - 它的 Label children 有...
[string-length(preceding-sibling::Label/LabelText/text()) = 5 - 文本长度等于 5 的同级 Label/LabelText 节点...
and starts-with(preceding-sibling::Label/LabelText/text(), "BE") - 文本以 BE
and number(substring(preceding-sibling::Label/LabelText/text(), 3)) = number(substring(preceding-sibling::Label/LabelText/text(), 3))] - 最后 3 个字符是数字
/LabelText[@language="EN"]/text() - 获取具有 language 属性的 LabelText 节点的文本 EN

Symfony2 - DomCrawler - 通过正则表达式中的相邻内容获取元素的内容

Symfony2 - DomCrawler - fetch element's content by it's neighbour content in regex

regex

xml

web-crawler

symfony

domcrawler