How to make IE6, 7 not load images from cache

[figo2476]

Basically, a image will be updated over time, but it is always has the same name.

Safari and firefox understand the difference and will load the latest image. IE6,7 have

a little problem and it will load the cache image.

 

I have tried

<?php header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1 ?>

<?php header('Pragma: no-cache'); ?>

It doesn't work in all browsers and I guess the php page flow is not as simple as from top to bottom.

It won't be desirable, since the page has many images and it should reload a particular image.

 

Not sure how to work around this....

[phpzone]

 

I'm not sure of the real cause, but have you also set an expiry date on the entire page with meta expires?

[thebadbad]

If nothing else works, you could put a random query string on the image path, like:

 

<?php
echo '<img src="some_image.jpg?', uniqid(), '" alt="" />';
?>

 

Will output something like

 

<img src="some_image.jpg?48353bab35680" alt="" />

 

And the same image "some_image.jpg" will always be loaded, but it will look different to the browser every time (the query string does nothing to the image).

[kev wood]

to ad the expiry date header you should always use a date which is set in the past the line you should use should look like this

 

header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');

 

when ever i have had problems with images being cached i have added the random number to them i find it works better than trying to stop the caching of the images.  the random number syntax i use it this

 

$rand = rand (0,100);

<img src = "your_image.gif.'?'.$rand"

 

that line of code should display the image with a number appended to the end of the file so it will always have some part of the file which is different to the last it tried to display

[thebadbad]

so it will always have some part of the file which is different to the last it tried to display

 

Well, not always with rand(0, 100), that's why I used uniqid().

[kev wood]

point taken but it still only has a 1 in 100 chance of displaying the same file, and the number could just be given a bigger range to work from.

[mlin]

thebadbad's solution will be faster and better chance of getting the results you want...go with that.

 

Never seen that before...very clever thebadbad

[figo2476]

Wow.. thank you for everyone. Hmm.. Not sure why IE6, 7 cannot figure it out. FF and safari understand the difference of same name, but modified file.