Pass variable from image to next page

Question

Hey I have dynamic image begin created with imagecreate(), and I have random values being produced, and I want to pass that random number, to a variable, and use that variable inside the page where Im using the image source.

The image is on random.php, and Im using <img src="random.php" /> on page index.php if that matters, and I want to pass from random.php (the image), to index.php. I already tried sessions and cookies but when I refresh, its always 1 step behind what the image is producing...

Im using a for loop to echo random numbers, I need to pass those numbers to a variable. Basicly how do I get numbers outside an image, in real time, not 1 step back.

Answer 1

The problem you are having is that index.php is requested, then the browser realizes that random.php is needed, so- yes, random.php will be a step AFTER index.php...

If you switch your "random creation" logic around, (have index create the key stored in a session, which can then be read from random.php) it may solve your problem.

Answer 2

What about using a temporary session variable?

On your first page,

<?php
    session_start();
    $_SESSION['mykey'] = 'myrandomval';
    session_write_close(); // Helpful if you're using a header redirect
?>

and on the second page

<?php

    session_start();
    $value = $_SESSION['mykey'];

?>

Answer 3

Instead of passing variables from the page to the image, you could set the random number generator seed to the same value on both scripts. Here is a full sample:

<?php

function randomcolor()
{
    srand( $_SERVER['REQUEST_TIME'] );
    $colors = array('red', 'green', 'blue', 'black', 'orange');
    return $colors[ array_rand($colors) ];
}

$color = randomcolor();

if(isset( $_GET['image'] ))
{
    header('Content-type: image/png');
    $im = imagecreate(75, 50);
    imagecolorallocate($im, 0xee, 0xee, 0xee);
    $black = imagecolorallocate($im, 0, 0, 0);
    imagestring($im, 2, 10, 10, $color, $black);
    imagepng($im);
    exit;
}

?>

<p>color: <?php echo $color; ?></p>
<img src="test5.php?image=1" />

This is two separate requests being seeded with the REQUEST_TIME, which means array_rand will return the same value both times.