Smart Pagination Algorithm

When implementing pagination, it's often desirable to limit the number of page links displayed to avoid overwhelming the user. This can be achieved by using a "smart" pagination algorithm that only shows a few adjacent pages to the current page.

Example Algorithm

The following PHP code demonstrates a smart pagination algorithm that truncates the page list to show only two adjacent pages to the current page:

query("SELECT * FROM mytable LIMIT $start, $limit")
    ->fetchAll();

// Calculate total number of pages
$total_pages = count($data);

// Setup page variables
$prev = $page - 1;
$next = $page   1;
$lastpage = ceil($total_pages / $limit);
$lpm1 = $lastpage - 1;

// Generate pagination markup
$pagination = "";

if ($lastpage 
This algorithm uses the adjacents variable to control the number of adjacent pages shown on each side of the current page. It also includes the following features:
Ellipsis: If there are more pages than can be displayed, it uses an ellipsis to truncate the page list.
First and last pages: It always shows the first and last pages, regardless of the current page.
Disabled buttons: It disables the previous and next buttons when the current page is the first or last page, respectively.
Active class: It adds the "active" class to the current page's link.