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phpdomdocumentchild-nodes

How to get all child nodes from DOMDocument?

I have the following

$string = '<html><head></head><body><ul id="mainmenu">
  <li id="1">Hallo</li>
  <li id="2">Welt
    <ul>
      <li id="3">Sub Hallo</li>
      <li id="4">Sub Welt</li>
    </ul>
  </li>
</ul></body></html>';
$dom = new DOMDocument;
$dom->loadHTML($string);

now I want to have all li IDs inside one array.
I tried the following:

$all_li_ids = array();
$menu_nodes = $dom->getElementById('mainmenu')->childNodes;
foreach($menu_nodes as $li_node){
    if($li_node->nodeName=='li'){
        $all_li_ids[]=$li_node->getAttribute('id');         
    }
}
print_r($all_li_ids);

As you might see, this will print out [1,2]

How do I get all children (the subchildren as well [1,2,3,4])?

Solution

  • My test doesn't return element by using $dom->getElementById('mainmenu'). But if your using does, do not use Xpath

    $xpath = new DOMXPath($dom);
$ul = $xpath->query("//*[@id='mainmenu']")->item(0);

$all_li_ids = array();
// Find all inner li tags
$menu_nodes = $ul->getElementsByTagName('li');
foreach($menu_nodes as $li_node){
        $all_li_ids[]=$li_node->getAttribute('id');         
}
print_r($all_li_ids); 1,2,3,4