文档末尾的Xml Php警告额外内容

Question

I'm trying to write a droid app that sends and receives XML between the app and a web service. When I try to run the following code

$dom = new domDocument;
$dom = simplexml_load_file('php://input');
$xml = simplexml_import_dom($dom);

$messages = Messages::find_by_sql("SELECT * FROM messages WHERE reciever = '$xml->userName'");
$xmlString = "";
if($messages)
{

    foreach($messages as $message)
    {
    $ts = strtotime($message->ts);
 $xmlString=$xmlString."<Message><sender>".$message->sender."</sender><reciever>".$message->reciever."</reciever><timestamp>"."123"."</timestamp><text>".$message->text."</text></Message>";
    }
}
else
{
    //do something
}
$xmlReturn = new DOMDocument('1.0', 'UTF-8');
$xmlReturn->loadXML($xmlString);
echo($xmlReturn->saveXML());
?>

I get a Warning Extra content at the end of the document.

The error comes from this line: $xmlReturn->loadXML($xmlString);

I'm not 100% sure that you can create an xml document by loading a string, but I've seen similar things done and if you look here you can see what it ouputs, which looks like valid XML to me.

Answer 1

An XML document can have only one root element. You are stringing together multiple <message>…</message> combinations here, so a root element encapsulating those is missing.