How to submit file upload form with ajax? [duplica

问题:

Possible Duplicate:
Ajax file upload

Is it possible to write an ajax request with JQuery that "submits" a form with a file field? I want to do it because in this way i can make the user upload a file without leaving the current page.

How should i write the $.ajax() call? and in particular how should i set into the ajax call the file field?

EDIT: I'd like to use only core JQuery functions, without plugins.

Thanks.

回答1:

To maintain compatibility with the widest range of browsers this needs to be done through a hidden iframe.

Here is some sample code to demonstrate what I mean:

<iframe name="my_iframe" id="my_iframe" style="display: none;"></iframe>

<form action="/next_step.php" method="post" target="my_iframe" entype="multipart/form-data">
    <input type="file" name="file_upload" />
    <input type="button" id="upload_btn" value="Upload file" />

    <label for="name">Name</label>
    <input type="text" name="name" id="name" />

    <input type="submit" value="Next step" />
</form>

<script type="text/javascript">
    var btn = document.getElementById('upload_btn');
    btn.onclick = function(){
        var form_elem = document.forms[0];
        // direct file uploads through the hidden iframe
        form_elem.action = '/test_file.php';
        form_elem.target = 'my_iframe';

        // submit the form
        form_elem.submit();
    };
</script>

There are projects out there that make this easier such as Plupload

回答2:

It's hard. You're much better to use a service that already exists.

I did this recently on a site because I needed the whole form to submit without reloading the page, and uploadify was the best AJAX file uploader I found.