Can I delete file from temporary internet files in javascript?

Question

I have a page which needs to download an image file on onload event but, for all page calls! Now, it downloads the image in first call but in second call it gets from temporary and that is not the thing I want. I need to make some calculations for each load. So I want to delete the file that I download on each load from temporary or something else that forces client to download it from server again.

A javascript solution will be great. Thanks.

Answer 1

I would set the HTTP header for the image that's being downloaded to Cache-Control : no-cache, rather than coming up with some javascript "hack".

Answer 2

I understand you are looking for a javascript solution, but the good way to solve this is to use HTTP response headers which specify no-cache and expiry values. If you have no control over the web server configuration with .htaccess, you can create a simple PHP script that sets these headers before serving the content. In PHP:

header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');

Answer 3

No, you can't do anything at all to the cache using Javascript, but you can change the url of the image so that it's not in the cache.

Just add a query string to the url of the image, and use the current time to make it unique each time:

<script type="text/javascript">
document.write('<img src="images/theImage.gif?t=' + new Date().getTime() + '" alt="" />');
</script>

Answer 4

You definitely can't delete a temporary file with javascript. To avoid caching use the no-cache header when sending the image. This way the image will be downloaded every time is requested.

List of headers here.

You must use:

Cache-Control: no-cache

This is Microsoft specific.

Answer 5

Modify URL string to something like this:

originalUrl += "?" + new Date().getTime();