CODEWITHSUNDEEP
phphtml
theThirdZA
theThirdZA

Reputation: 17

Trying to use php to make a simple image "gallery" in a webpage

I am trying to make a basic gallery of sorts to put on a web page. This is my code so far:

<?
if($_REQUEST['cho'] == 'next')
{
  $img = $img + 1;
}
else
if($_REQUEST['cho'] == "previous")
{
  $img = $img - 1;
}
else
if(!$_REQUEST['cho'] == 'next')
{
  if(!$_REQUEST['cho'] == "previous")
  {
    $img = 1;
  }
}
?>

<center>
<table border =1>
<tr>
<td>
<form action="image.php" method="post">
<input type="submit" name="cho" value="previous">
</form>
</td>
<td>
<form action="image.php" method="post">
<input type="submit" name="cho" value="next">
</form>
</td>
</tr>
<BR>
<table border =1>
<tr>
<td>
<img src="<? echo($img . ".jpg"); ?>">
</td>
</tr>
</table>

It is all saved in a file called image.php.

I can view the first image (named 1.jpg, all images are named like this.) and pushing the next button displays the second. But from then on pushing the previous button tries to load -1.jpg and next just loads the current image.

Thanks.

Upvotes: 0

Views: 106

Answers (2)

Felix Carmona
Felix Carmona

Reputation: 611

use php sessions, or save it and pass it in a query string (?img=3 instead of ?cho=next, and auto compute the next and previous link)

<?php
$totalImages = 5;

session_start();
if (!isset($_SESSION['currentImage'])) {
  $_SESSION['currentImage'] = 1;
}

if($_REQUEST['cho'] == 'next')
{
   if($_SESSION['currentImage'] === $totalImages) {
       $_SESSION['currentImage'] = 1;
   } else {
       $_SESSION['currentImage']++;
   }

}
elseif($_REQUEST['cho'] == "previous")
{
   if($_SESSION['currentImage'] === 1) {
       $_SESSION['currentImage'] = $totalImages;
   } else {
       $_SESSION['currentImage']--;
   }
}

?>

Upvotes: 0

adanot
adanot

Reputation: 328

This has to do with the scope of the variable $img. You currently have it being declared in each if statement. You should declare the variable before any looping so the value is persistent.

Take a look here: 

<?

 $img = 1;

if($_REQUEST['cho'] == 'next')
{
  $img = $img + 1;
}
else
 if($_REQUEST['cho'] == "previous")
 {
   $img = $img - 1;
 }
else
 if(!$_REQUEST['cho'] == 'next')
{
  if(!$_REQUEST['cho'] == "previous")
  {
    $img = 1;
  }
}
?>

Upvotes: 1

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