JSON request failed with file upload

[mr.]

Here I have a normal form like this :

<form id="form" name="form" method="post" action="upload.php"
enctype="multipart/form-data">
<input type="file" size="20" name="handle" id="handle">
<input type='submit' name='submit' id='submit' value='Submit'>
</form>

Of course, it works fine but if I try :

<script type='text/javascript' src='mootools-1.2.js'></script>
<script>
window.addEvent('domready', function() {
$('submit').addEvent(
'click', function(e) {
e = new Event(e).stop();
var jsonRequest = new Request.JSON({onComplete: function(result){
alert(result.id);
}}).post($('form'));
}
);
});
</script>
<form id="form" name="form" method="post" action="upload.php"
enctype="multipart/form-data">
<input type="file" size="20" name="handle" id="handle">
<input type='submit' name='submit' id='submit' value='Submit'>
</form>

Then nothing happen but a strange message from FireBug :
[Exception... "Component returned failure code: 0x80070057
(NS_ERROR_ILLEGAL_VALUE) [nsIXMLHttpRequest.open]" nsresult:
"0x80070057 (NS_ERROR_ILLEGAL_VALUE)" location: "JS frame ::
javascript: eval(__firebugTemp__); :: anonymous :: line 1" data: no]

And in IE is :
Line: 3626
Char:3
Error: Invalid argument.
Code: 0

Can anybody tell me why please ? I'm really get stuck with it.

[johnwait]

Most probably your server doesn't send back a valid JSON response.

[mr.]

No, it's because that XHR does not support file upload so that any
<input type='file'> will be ignored >"< and I will have to use
<iframe> to handle file upload.

[moussor]

Hi, i'm working on a form with file upload too (not with Request.JSON
but with Request.HTML) and I came to the same conclusion. That's a
bummer. Hopefully the Request class can be extended to allow file
uploads or as you said maybe an iframe is simpler but I have no idea
how to do that.

[Jan Kassens]

XHR cant send files. There are some workarounds, but nothing built-in.
- using a hidden iframe where the form is submitted
- digitaralds FanzyUpload (digitarald.de) which uses Flash in the
background
- good old plain forms ;)

Jan

--
my blog: http://blog.kassens.net

[Tim Lavelle]

That explains why my previous file uploads weren't working when I wasn't
using fancy upload.

TY

[jeresch]

Hello,

I've the same problem with a file upload form which can't be handled
by Request.HTML.

How can I use an IFrame instead of Request.HTML to submit the form ?
The problem is that after submitting the form, I want to get out of
the IFrame with the datas sent by the form. Is it possible to do that
and how can it be done ?