Question

I am using this version of jQuery form plugin https://raw.github.com/malsup/form/master/jquery.form.js
getting an error on submit:

error on line form.submit();

SCRIPT87: Invalid argument. jquery.form.js, line 347 character 5

My code:

<form id="ajaxUploadForm" action="@Url.Action("Upload", "Home")%>" method="post" enctype="multipart/form-data" >
    <fieldset>
        <legend>Upload a file</legend>
        <label>File to Upload: <input type="file" name="file" /></label>
        <input id="ajaxUploadButton" type="submit" value="Upload" />
    </fieldset>
</form> 

$(function () {
        $("#ajaxUploadForm").ajaxForm({
            iframe: true,
            dataType: "json",
            beforeSubmit: function () {
               // $("#ajaxUploadForm").block({ message: '<img src="/Content/themes/start/images/progress.gif" />' });
            },
            success: function (result) {
               // $("#ajaxUploadForm").unblock();
                //$("#ajaxUploadForm").resetForm();
                $.growlUI(null, result.message);
            },
            error: function (xhr, textStatus, errorThrown) {
                //$("#ajaxUploadForm").unblock();
                //$("#ajaxUploadForm").resetForm();
                $.growlUI(null, 'Error uploading file');
            }
        });
    });

I am doing this upload in side simple model dialog.

May be some one may have any ideas how ti fix that?

Answer 1

If the controller action that you are POSTing to is returning JSON you might need to wrap it in a <textarea> tags as explained in the documentation:

Since it is not possible to upload
files using the browser’s
XMLHttpRequest object, the Form Plugin
uses a hidden iframe element to help
with the task. This is a common
technique, but it has inherent
limitations. The iframe element is
used as the target of the form’s
submit operation which means that the
server response is written to the
iframe. This is fine if the response
type is HTML or XML, but doesn’t work
as well if the response type is script
or JSON, both of which often contain
characters that need to be repesented
using entity references when found in
HTML markup.

To account for the challenges of
script and JSON responses, the Form
Plugin allows these responses to be
embedded in a textarea element and it
is recommended that you do so for
these response types when used in
conjuction with file uploads. Please
note, however, that if there is no
file input in the form then the
request uses normal XHR to submit the
form (not an iframe). This puts the
burden on your server code to know
when to use a textarea and when not
to. If you like, you can use the
iframe option of the plugin to force
it to always use an iframe mode and
then your server can always embed the
response in a textarea.