How to stop array id as variable resetting

[db9]

Hi, I think this is probably a logical error rather than a syntax one

 

I have a function that displays the first image in a photo album in large and all the photos in it as thumbnails. I have a next and previous button that allows you to scroll through them (in large) and by clicking a specific thumbnail you can load that picture in large. My problem is that the pictures are stored in an array and the one to be shown large is selected by $keyid.

 

My problem is that selecting a thumbnail resets the $keyid so that clicking next doesn't load the next image but the second. i.e. if you press the next arrow then click the 4th thumbnail and then click the next arrow again it loads the 2nd picture rather than the 5th as it should.

 

How can I avoid this happening?

 

This is my code:

generateThumbnails();

$act = 0;

$keyid = (isset($_GET['keyid']) ? $_GET['keyid']:'0');

$Picturecount = (count(glob("" . $dir . "*.jpg")))/2;

$thumb_selected = (isset($_GET['thumb']) ? $_GET['thumb']:'');

$picture_array = glob("$dir*");

if ($thumb_selected !==""){
$dirName  = substr($thumb_selected,0,strpos($thumb_selected,basename($thumb_selected)));
$thumbName = basename($thumb_selected);
$thumbFile = $dirName.$thumbName;
$selected = str_replace('_th.jpg','.jpg',$thumbFile);
foreach ($picture_array as $search){
$keyid = array_search($selected,$picture_array);
$large = $picture_array[$keyid];
}}

else{
if($keyid > (2*$Picturecount-1)){
$keyid = ($keyid - (2*$Picturecount));}
if($keyid < 0){
$keyid = (2*$Picturecount+$keyid);}
$large = $picture_array[$keyid];}

echo "

<tr><td><a href='?album=$album&keyid=" . ($_GET['keyid']-2) . "'>Previous</a></td><td></td><td align='right'><a href='?album=$album&keyid=" . ($_GET['keyid']+2) . "'>Next</a></td></tr>

<tr><td colspan='3' height='300' width='400' align='center'><img src='$large' alt=''></td></tr><tr><td height='50'></td></tr>";

 

Any help would be massively appreciated. Thanks very much!

[db9]

I think what I want to do is have the GET['keyid'] bit check whether keyid has been set in my foreach loop or not yet before taking it from the url/setting it to zero. Is this possible/how would I do it? Thanks

[PradeepKr]

What is the use of foreach loop here. I find it redundant.

 

Try echoing the $keyid in the else part and just before calculating the $large.

 
else
{
echo "key value before |$keyid|";
  if($keyid > (2*$Picturecount-1)){
    $keyid = ($keyid - (2*$Picturecount));}
  if($keyid < 0){
    $keyid = (2*$Picturecount+$keyid);}
echo "key value after |$keyid|";
  $large = $picture_array[$keyid];
}

 

I think you can come to know then. Else paste the output.

[db9]

Hi thanks for the help. I tried echoing the $keyid like you said but all it does is output the right $keyid if the next arrow has been pressed but nothing if a thumbnail has been selected (as expected?) so I'm not really sure how that helps?

 

The foreach loop is supposed to go through each picture in the array and check if the $keyid matches the one of the thumbnail clicked. Why is that redundant? Thanks again.