从PHP中的DomeElement获取特定的子标记

我正在浏览一个xml定义文件，我有一个域名列表。 我需要提取当前实体中可能存在或不存在的子标记的内容

<input id="name">
  <label>Full Name:</label>
  <required />
</input>
<input id="phone">
  <required />
</input>
<input id="email" />

预期结果：

Array(
  ['name'] => "Full Name:"
  ['phone'] => 
)

---

奇怪的是：你已经知道答案了，因为你已经在剧本中使用了它。
但这次不是将DOMDocument作为上下文“节点”，而是使用

input

domeElement：

<?php
$doc = getDoc();
foreach( $doc->getElementsByTagName('required') as $e ) {
  $e = $e->parentNode; // this should be the <input> element
  // all <label> elements that are direct children of this <input> element
  foreach( $e->getElementsByTagName('label') as $l ) {
    echo 'label="', $l->nodeValue, "\"\n";
  }
}

function getDoc() {
  $doc = new DOMDocument;
  $doc->loadxml('<foo>
    <input id="name">
      <label>Full Name:</label>
      <required />
    </input>
    <input id="phone">
      <required />
    </input>
    <input id="email" />
  </foo>');
  return $doc;
}

---

Rock，可以了，谢谢！
<?php
$doc = getDoc();
foreach( $doc->getElementsByTagName('required') as $e ) {
  $e = $e->parentNode; // this should be the <input> element
  // all <label> elements that are direct children of this <input> element
  foreach( $e->getElementsByTagName('label') as $l ) {
    echo 'label="', $l->nodeValue, "\"\n";
  }
}

function getDoc() {
  $doc = new DOMDocument;
  $doc->loadxml('<foo>
    <input id="name">
      <label>Full Name:</label>
      <required />
    </input>
    <input id="phone">
      <required />
    </input>
    <input id="email" />
  </foo>');
  return $doc;
}