使用 xpath 选择具有属性值的整个节点

Question

大家好，我有一个奇怪的问题（对我来说很奇怪）。我有一个 xml 文件 如下：

<?xml version="1.0" encoding="ISO-8859-1"?>
<StudentsList>
<Student>
<student_id email="test@yahoo.com">18700</student_id>
<firstName>Jhon</firstName>
<lastName>Smith</lastName>
<address>Dragon Vally china</address>
</Student>
<Student>
<student_id email="LeeSin@gmail.com">18701</student_id>
<firstName>Lee</firstName>
<lastName>Sin</lastName>
<address>League Of Legend UK</address>
</Student>
</StudentsList>

当我在 php 中使用 xpath 搜索该文件时

$allStudents = $xml->xpath("//StudentsList/Student");

它给了我一个数组中的所有学生，他们的子节点和值如下：

Array ( [0] => SimpleXMLElement Object ( [student_id] => 18700 [firstName] => Jhon [lastName] => Smith [address] => Dragon Vally china ) [1] => SimpleXMLElement Object ( [student_id] => 18701 [firstName] => Lee [lastName] => Sin [address] => League Of Legend UK ) [2] => SimpleXMLElement Object ( [student_id] => 18702 [firstName] => Xin [lastName] => Xaho [address] => Shanghi China ) [3] => SimpleXMLElement Object ( [student_id] => 18703 [firstName] => corki [lastName] => adc [address] => flying machine gun china ) [4] => SimpleXMLElement Object ( [student_id] => 18704 [firstName] => Kog [lastName] => Maw [address] => Depth of The Hell ) )

但由于我有一个 student_id 节点的属性，所以我也想获得该属性的值，任何人都可以建议我为此做些什么，我用谷歌搜索了很多，但没有找到正确的答案。他们给出了通过属性值选择父母的例子，但至少我没有找到用整个学生节点选择它的人。

Answer 1

您可以以$element['foo'] 的形式访问名为foo 的属性，例如

$xml = <<<XML
    <StudentsList>
<Student>
<student_id email="test@yahoo.com">18700</student_id>
<firstName>Jhon</firstName>
<lastName>Smith</lastName>
<address>Dragon Vally china</address>
</Student>
<Student>
<student_id email="LeeSin@gmail.com">18701</student_id>
<firstName>Lee</firstName>
<lastName>Sin</lastName>
<address>League Of Legend UK</address>
</Student>
</StudentsList>
XML;

$doc = new SimpleXMLElement($xml);

foreach ($doc->Student as $student) {
    echo $student->student_id['email'] . "\n";
}

输出两个电子邮件地址，当然使用 XPath 代码是相同的：

$xml = <<<XML
    <StudentsList>
<Student>
<student_id email="test@yahoo.com">18700</student_id>
<firstName>Jhon</firstName>
<lastName>Smith</lastName>
<address>Dragon Vally china</address>
</Student>
<Student>
<student_id email="LeeSin@gmail.com">18701</student_id>
<firstName>Lee</firstName>
<lastName>Sin</lastName>
<address>League Of Legend UK</address>
</Student>
</StudentsList>
XML;

$doc = new SimpleXMLElement($xml);


foreach ($doc->xpath("//StudentsList/Student") as $student) {
    echo $student->student_id['email'] . "\n";
}