PHP DOMNode :: hasAttributes检查失败

Question

I am using PHP DOMNode hasAttributes to retrieve all of the elements' attributes. So far, everything is working great. My code is below. However, this line else if($imageTags->hasAttributes() == false) is where I can't get it to work, it displays error on my page instead redirecting the user to index php when code failed to work. What I really want is if ($imageTags->hasAttributes() == true) does not equal TRUE. Redirect the user to index.php and don't display the errors instead.

function get_iframe_attr($string){
        $doc = new DOMDocument();
        $doc->loadHTML("$string");

            $imageTags = $doc->getElementsByTagName('iframe')->item(0);
            if ($imageTags->hasAttributes() == true) {
              foreach ($imageTags->attributes as $attr) {
                $name = $attr->nodeName;
                $value = $attr->nodeValue;
                $attr_val[] = "$name=\"$value\" ";

              }
              echo  $implode_str = implode(" ", $attr_val);
            }else if($imageTags->hasAttributes() == false){
              header("Location: index.php");
            }

        } 


get_iframe_attr('<iframe src="" scrolling="no" width="600" height="438" marginheight="0" marginwidth="0" frameborder="0"></iframe>');

Note: if you remove the '<iframe' tags on the string. You will get the error

Answer 1

...
} else if($imageTags->hasAttributes() == false){
   header("Location: index.php");
   die; // needed here to prevent code below, if any from executing
}
...

also on your edit note about removing iframe and getting error, you need to check if $doc->getElementsByTagName('iframe') has actually grabbed anything, example:

$imageTags = $doc->getElementsByTagName('iframe')
if ($imageTags->length > 0) {
   $imageTags = $imageTags->item(0);
   ...