XPath查詢返回不同級別的多個節點

Question

PHP XPath查詢：

$query = $xpathvar->query('//siri:Service');
foreach($query as $service) {
    echo $service->textContent;
    // Here I need to also echo this Vehicle's reg
}

目標XML：

<Vehicle>
    <CategoryA>
        <Service>123123123</Service>
    </CategoryA>
    <CategoryB>
         <SubCategoryA>
             <Reg>ASDF_XC1</Reg>
         </SubCategoryA>
    </CategoryB>
</Vehicle>
// Imagine many more vehicles here each with a service and reg

我該如何更改PHP，以便同時檢索每個Reg？ 取回時，服務和Reg必須位於同一輛車內（不是隨機對）。

Answer 1

查詢車輛，然后將其用作上下文節點以搜索Service和Reg怎么樣？

$vehicles = $xpath->query('//siri:Vehicle');
$pairs = array();
foreach ($vehicles as $vehicle) {
    $pairs[] = array(
        'Service' => $xpath->evaluate('string(.//siri:Service)', $vehicle),
        'Reg'     => $xpath->evaluate('string(.//siri:Reg)'    , $vehicle),
    );
}

另請參閱：

• 將兩個Xpath組合成一個循環？