Sé que este tema ya se ha comentado en más de una ocasión y que se han propuesto varios códigos. Yo tenía uno y lo he reescrito recientemente, pero no he tenido tiempo de probarlo todavía (es posible que tenga algún fallo). Por si a alguien le sirve o si lo quiere mejorar/modificar, aquí lo pongo:
Código PHP:
<?php
//////// class_pages.php ////////
// Class for handling page sets
// Author: Ricardo Cervera Navarro (lical)
// <[email protected]>
// Created: 28.08.02, Rewritten: 22.08.03
// This code is (C) Ricardo Cervera
// This code is under the terms of the
// GNU General Public License in its last version.
// Thanks:
// -> Ferdy, helped me starting in OOP
// -> Moi, advice with last_page() function
class pages {
// Stores the number of the actual page
var $current_page;
// Stores how many items are displayed in each page
var $items_each_page;
// Stores the number of the previous page
// If there's no prev. page, it will contain (bool) false
var $previous_page;
// Stores the number of the next page
// If there's no prev. page, it will contain (bool) false
var $next_page;
// Number of total items to be handled
var $num_total_items;
// This array contents the first matching item and the last
// for the current page, normally, starting counting at 1
// $limit[0] is the first item and $limit[1] is the last item
var $limit = array();
// This array's content is explained in compute_limits() function
// $limit[0] is the first item and $limit[1] is the last item
var $lmysql = array();
// Stores the number of the last page available
var $last_page;
// Class constructor, the arguments are: current page number,
// number of items displayed in each page, and
// number of total results to be handled (starting counting at 1)
function pages($actual_page, $items_each_page, $num_total_items)
{
$this->actual_page = (int) $actual_page;
$this->items_each_page = $items_each_page;
$this->num_total_items = $num_total_items;
$this->previous_page = $this->exists_page($this->actual_page-1);
$this->next_page = $this->exists_page($this->actual_page+1);
$this->last_page = $this->last_page();
if ( exists_page($actual_page) == false ) {
return false;
}
$this->limit = compute_limits();
$this->lmysql = compute_limits("mysql");
}
// This function computes the last page available
// (according to the number of total items to handle)
function last_page()
{
$last_page = $this->num_total_items / $this->items_each_page;
$last_page = ceil($last_page);
if ( $this->num_total_items == 0 ) {
return 1;
} else {
return $last_page;
}
}
// This function gets the number of the first item and the last item
// for the current page.
//
// It takes "mysql" as argument if you want to count
// for MySQL LIMIT function (this means the first item for this
// page starting counting them at 0 and last item is
// [items a page]), otherwise (for normal count
// and starting counting at 1) it takes no argument
function compute_limits($starting_value="normal")
{
switch($starting_value) {
case "mysql":
$limit[0] = $this->items_each_page * $this->actual_page
- $this->items_each_page;
$limit[1] = $this->items_each_page;
return $limit;
break;
case "normal":
$limit[0] = $this->items_each_page * $this->actual_page
- $this->items_each_page + 1;
if ( $this->next_page == false ) {
$limit[1] = $this->num_total_items;
} else {
$limit[1] = $limit[0] + $this->items_each_page - 1;
}
return $limit;
break;
default:
return false;
break;
}
}
// This function checks whether a page exists or not
function exists_page($page_number)
{
$page_number = (int) $page_number;
if ( $page_number >= 1 &&
$page_number <= $this->last_page ) {
return $page_number;
} else {
return false;
}
}
}
?> Un saludo,
