Checks if attribute is a defined ID ()

DOMAttr {
  bool isId();

This function checks if the attribute is a defined ID.

According to the DOM standard this requires a DTD which defines the attribute ID to be of type ID. You need to validate your document with DOMDocument->validate() or DOMDocument::validateOnParse before using this function.


如果成功则返回 TRUE,失败则返回 FALSE


例 461. DOMAttr->isId() Example


= new DomDocument;

// We need to validate our document before refering to the id
$doc->validateOnParse = true;

// We retrieve the attribute named id of the chapter element
$attr = $doc->getElementsByTagName('chapter')->item(0)->getAttributeNode('id');

var_dump($attr->isId()); // bool(true)