php - Why are empty arrays being hidden when outputting them as XML? -

i'm trying have php convert nested arrays xml document. i've been unable troubleshoot why arrays no children being hidden xml output entirely; want them show having no children in xml too.

here's relevant code snippet:

private function response_xml_encode($node, $data) {   if ($node == null) return false;   if (!is_array($data)) return false;   foreach ($data $key => $value)   {     if (is_array($value) && !$this->response_xml_encode_assocarray($value))     {       foreach ($value $val)         $node->addchild($key, htmlentities($val));     }     else if (is_array($value))     {       $this->response_xml_encode($node->addchild($key), $value);     }     else if (!$this->response_xml_encode_validkey($key))     {       $subnode = $node->addchild($node->getname(), htmlentities($value));       $subnode->addattribute('keyinvalid', 'true');       $subnode->addattribute('key', htmlentities($key));     }     else     {       $node->addchild($key, htmlentities($value));     }   } }  private function response_xml_encode_assocarray($arr) {   // let's know if array has associative key value pairs, or if has numeric key value pairs   // returns true if array has non-numeric key in   foreach ($arr $key => $value)   {     if (!is_numeric($key)) return true;   }   return false; }  private function response_xml_encode_validkey($key) {   if (strpos('abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz_', substr($key, 0, 1)) === false) return false;   return (preg_match('/[^a-za-z_-]/s', $key) === 0); } 

i call using:

$response = array(   'result' => 0,   'message' => 'success.',   'function' => 'test',   'data' => array(     'get'  => $_get,     'post' => $_post,     'foo'  => array(       'bar' => array(         'bad' => array(           'wolf' => array(             'some_value' => 'testtesttest'           )         )       )     )   ) ); $root = new simplexmlelement('<?xml version="1.0" encoding="utf-8"?><response/>'); $this->response_xml_encode($root, $response); return $root->asxml(); 

note $_get , $_post empty arrays.

the following gets returned:

<?xml version="1.0" encoding="utf-8"?> <response>   <result>0</result>   <message>success.</message>   <function>test</function>   <data>     <foo>       <bar>         <bad>           <wolf>             <some_value>testtesttest</some_value>           </wolf>         </bad>       </bar>     </foo>   </data> </response> 

but what's expected show <get/> , <post/> before shows <foo>:

<?xml version="1.0" encoding="utf-8"?> <response>   <result>0</result>   <message>success.</message>   <function>test</function>   <data>     <get/>     <post/>     <foo>       <bar>         <bad>           <wolf>             <some_value>testtesttest</some_value>           </wolf>         </bad>       </bar>     </foo>   </data> </response> 

you have put below code snippet @ starting foreach loop

foreach ($data $key => $value) {        if(array_key_exists($key, $data) && empty($value))    {        $node->addchild($key, "");    }    //your other code goes here } 

above code output desired output below.

<?xml version="1.0" encoding="utf-8"?> <response>     <result>     </result>     <message>success.</message>     <function>test</function>     <data>         <get>         </get>         <post>         </post>         <foo>             <bar>                 <bad>                     <wolf>                         <some_value>test test test</some_value>                     </wolf>                 </bad>             </bar>         </foo>     </data> </response> 

i had taken code sample , executed creating class. should working also.