PHP File Download using POST data via jQuery AJAX

Question

So I know there have been a number of similar posts, but I think this is enough of a variation to warrant its own question:

I am building an XLS exporter in PHP and jQuery. I am trying to POST an array with jQuery (which I believe is going to be too long as a GET querystring), and use it to generate an XLS file on my server, which the user can then download.

I have used hidden iframes in the past to accomplish this, but since they just redirect to a url, this requires me to use GET, which makes me nervous.

My question is then: how do I store those files on my server and link to them if they're being generated dynamically, potentially by multiple users? Would a hidden iframe link to a separate PHP script that locates THEIR file based on a session ID or something like that?

Thanks in advance for any guidance here on what I'm sure gets asked all the time :)

Answer 1

It is possible to POST to a hidden iframe. Therefore, you don't need to worry about the length of the query string; you will post the key/value pairs which will generate your XLS file and subsequently force the file download to the browser.

<form method="post" action="/download/xls" target="download_xls"> 
  <fieldset>
    <label>Key 1:</label>
    <input type="text" name="key_1" />
  </fieldset>

  <fieldset>
    <label>Key 2:</label>
    <input type="text" name="key_2" />
  </fieldset>

    <fieldset>
            <input type="submit" value="Submit" /> 
    </fieldset> 
</form>

<iframe id="download_xls" name="download_xls" width="0" height="0" scrolling="no" frameborder="0"></iframe>

UPDATE A quick Google search turned up this article: http://particletree.com/notebook/ajax-file-download-or-not/

Basically, the suggestion is to POST your form to the current page and respond with a file download. This alternative might be good enough for you.