Upload onload don't work on firefox iframe

I am having a problem in Firefox with a file uploading into an iframe. An anchor should call the function dosubf() that posts the form to the iFrame to upload a XML file that will be开发者_如何学Python parsed later with Ajax and displayed in another form on the same page.

The iframe is generated dynamically into a div tag. When it loads the first time, works fine, but, in Firefox, when reloading the content into the div, result on an error 'var ret is null'! caught by the firebug extension. I have also noticed that another error occurs on a xmlhttp.open("POST", var, var.length) call that is made in order to generate one select html object into a table cell. Again the error shows that some var is null but in this case the function that dropping the program is out of the scope! Both functions are working fine in IE9.

For the first issue I think that it could be something related to the onload event. For the second I really don't know what's happening.

Below is the code that load an html form with method Ajax into the div for the initial input of the XML file.

<form id='file_upload_form' method='post' 
enctype='multipart/form-data'   target='upload_targetf' 
action='include/php/util/handle/handlexml.php'>

<input name="file" id="file" type="file" />
<a href="#" class="botao" onclick="dosubf()">IMPORT</a>

<iframe  id='upload_target' name='upload_targetf' onload='lerxml()' ></iframe>
</form>

The javascript for the event onclick of the button that submits the form.

function dosubf(){
    if (document.getElementById('file').value==''){
        alert ("Por favor seleccione um arquivo");
        return
        }
    document.getElementById('file_upload_form').submit();
}

And the function for the event onload that is firing well when it's the first load into the div of the HTML shown before, but fails when I refresh with Ajax that content on the div and try fire the onload. It fails in the second time on the fire empty onload iFrame and of course on button action submit onload.

function lerxml(){
    var ret = window.frames['upload_targetf'].document; 
//Here the code breaks with a ret is null error on firebug!
    var novostring='';
    var  d=ret.body.innerHTML;
    var mess='';
    if (d!=''){
        d=eval("("+d+")"); 
//This for getting the JSON response to evaluate the file
        if (d.tipo){
            mess+=(d.tipo);
        }
        if (d.tamanho){
            mess+=(d.tamanho);
        }
        var ok='';
        if (d.sucesso){
//The filepath of the uploaded file to use Ajax for parse it later
            novostring="arquivo/xml/"+d.sucesso;    
        }else{
            novostring="";
            alert (mess);
            return
        }
    }

The PHP that evaluate the file upload to the iFrame

<?
$erro = $config = array();

$arquivo = isset($_FILES["file"]) ? $_FILES["file"] : FALSE;

$config["tamanho"] = 500000;

if($arquivo){     

if(!preg_match("/^text\/xml$/",$arquivo["type"]))    {      
$erro['tipo'] = "Não é um arquivo XML! Por favor seleccione outro arquivo"; 
}    else    {        

if($arquivo["size"] > $config["tamanho"])        {            
$erro['tamanho'] = "Arquivo em tamanho muito grande!";
} 

}

if(sizeof($erro))    {
 foreach($erro as $err)      {
  $err=htmlentities($err);
 }

echo json_encode($erro);
die;
}else    { 

$imagem_nome = md5(uniqid(time())) . ".xml";

$imagem_dir ['sucesso'] = "arquivo/xml/" . $imagem_nome; 
move_uploaded_file($arquivo["tmp_name"],"../../../../".$imagem_dir ['sucesso']);
echo json_encode(htmlentities($imagem_dir));
}

}
?>

Well I hope 'twas clearly enough to reach some help from you.

Thank you in advance for any comments.

I bet you're running into https://bugzilla.mozilla.org/show_bug.cgi?id=170799

Try replacing window.frames['upload_targetf'].document with document.getElementById("upload_target").contentDocument, which won't have the same issue.