[RESOLVED] A back/forward button for images

phpmixx

I'm working on this webcomic calendar, and also the navigation part. The strips are organized by "Ymd" by date().

So lets say you have:

20080101.png
20080102.png
20080103.png
20080106.png
20080108.png
20080109.png

And you're on comic strip 20080106.png and need buttons to go back 1 strip or go forward 1 strip, but I can't do something like strtotime() and then date() again because it keeps messing up the date to something like December 31st, 1969.

Anyone got any solutions?

bpat1434

Well, here's an idea:

<?php

$strips = glob('*.png'); // Get all comic strips available
natsort($strips); // Sort them numerically

$current = array_search($_GET['strip'] . '.png', $strips);
$max = count($strips);

$previous = '&laquo; Previous';
$next = 'Next &raquo;';

if($current > 0)
    $previous = '<a href="?strip=' . substr($strips[$current-1], 0, 8) . '">' . $previous . '</a>';

if($current < $max)
    $next = '<a href="?strip=' . substr($strips[$current-1], 0, 8) . '">' . $next . '</a>';

echo $previous . ' &nbsp;&nbsp;&nbsp;&nbsp; ' . $next . '<hr />';

?>

Now, that's if you have nothing but YYYYMMDD.png formatted images in some folder. The glob function uses a limited regex ("" being any character any number of times) to find files in a certain folder matching that "pattern". So in our case, we want only ".png" files, so we use ".png" as the "pattern".

Then we sort them by date, and since they're always YYYYMMDD we can be sure where we are. We then get the correct array key using [man]array_search/man to find it. We add the ".png" extension since only the date is being passed via the URL.

Then it's just a matter of checking whether we can go back ($current is greater than 0) or if we can go forward ($current is less than $max).

Hope that helps.

phpmixx

bpat1434 wrote:
Well, here's an idea:
<?php

$strips = glob('*.png'); // Get all comic strips available
natsort($strips); // Sort them numerically

$current = array_search($_GET['strip'] . '.png', $strips);
$max = count($strips);

$previous = '&laquo; Previous';
$next = 'Next &raquo;';

if($current > 0)
    $previous = '<a href="?strip=' . substr($strips[$current-1], 0, 8) . '">' . $previous . '</a>';

if($current < $max)
    $next = '<a href="?strip=' . substr($strips[$current-1], 0, 8) . '">' . $next . '</a>';

echo $previous . ' &nbsp;&nbsp;&nbsp;&nbsp; ' . $next . '<hr />';

?>
Now, that's if you have nothing but YYYYMMDD.png formatted images in some folder. The glob function uses a limited regex ("" being any character any number of times) to find files in a certain folder matching that "pattern". So in our case, we want only ".png" files, so we use ".png" as the "pattern".

Then we sort them by date, and since they're always YYYYMMDD we can be sure where we are. We then get the correct array key using [man]array_search/man to find it. We add the ".png" extension since only the date is being passed via the URL.

Then it's just a matter of checking whether we can go back ($current is greater than 0) or if we can go forward ($current is less than $max).

Hope that helps.

Exactly what I was looking for. Thanks!

bpat1434

Glad I could help. Now for the obvious question: Does it work? I didn't really test the code before posting it (rather, wrote it in the post only). But as long as you understand what's going on, I guess it's just a "shell" for you to use.