PHP paging class calling example tutorial

/**
 * filename: ext_page.class.php
 * @package:phpbean
 * description: Super powerful paging class, four paging modes, and the default paging style is similar to Baidu and Google.
 * 2.0 added functions: support custom styles, custom styles, support both PHP4 and PHP5,
 * example:
 * Four paging modes:
 require_once('../libs/classes/page.class.php' );
 $page=new page(array('total'=>1000,'perpage'=>20));
 echo 'mode:1'.$page->show();
 echo 'mode:2'.$page->show(2);
 echo 'mode:3'.$page->show(3);
 echo 'mode:4'.$page->show(4);
 Turn on AJAX: bbs.it-home.org
 $ajaxpage=new page(array('total'=> 1000,'perpage'=>20,'ajax'=>'ajax_page','page_name'=>'test'));
 echo 'mode:1'.$ajaxpage->show( );
 Adopt inherited custom paging display mode:
*/
class Page
{
 /**
  * config ,public
*/
 var $page_name="p";//page tag , used to control the url page. For example, PB_page in xxx.php?PB_page=2
 var $next_page='>';//Next page
 var $pre_page='<';//Previous page
 var $first_page='First' ;//Homepage
 var $last_page='Last';//Last page
 var $pre_bar='<<';//Previous paging bar
 var $next_bar='>>';//Next A paging bar
 var $format_left='';
 var $format_right='';
 var $is_ajax=false;//Whether AJAX paging mode is supported
 /**
  * private
  *
* /
 var $pagebarnum=10;//Control the number of record bars.
 var $totalpage=0;//Total number of pages
 var $ajax_action_name='';//AJAX action name
 var $nowindex=1;//Current page
 var $url="";//url address header
 var $offset=0;
 /**
  * constructor构造函数
  *
  * @param array $array['total'],$array['perpage'],$array['nowindex'],$array['url'],$array['ajax']...
*/
 function page($array)
 {
 if(is_array($array)){
 //if(!array_key_exists ('total',$array))$this->error(__FUNCTION__,'need a param of total');
 $total=intval($array['total']);
 $perpage=(array_key_exists(' perpage',$array))?intval($array['perpage']):10;
 $nowindex=(array_key_exists('nowindex',$array))?intval($array['nowindex']):'' ;
 $url=(array_key_exists('url',$array))?$array['url']:'';
 }else{
 $total=$array;
 $perpage=10;
 $nowindex=' ';
 $url='';
 }
 //if((!is_int($total))||($total<0))$this->error(__FUNCTION__,$total.' is not a positive integer!');
 if((!is_int($perpage))||($perpage<=0))$this->error(__FUNCTION__,$perpage.' is not a positive integer!');
 if (!empty($array['page_name']))$this->set('page_name',$array['page_name']);//Set pagename
 $this->_set_nowindex($nowindex);/ /Set the current page
 $this->_set_url($url);//Set the link address
 $this->totalpage=ceil($total/$perpage);
 $this->offset=($this- >nowindex-1)*$perpage;
 if(!empty($array['ajax']))$this->open_ajax($array['ajax']);//Open AJAX mode
 }
 / **
 * Set the value of the specified variable name in the class. If the change does not belong to this class, an exception will be thrown
 *
 * @param string $var
 * @param string $value
*/
 function set($var,$value)
 {
 if(in_array($var,get_object_vars($this)))
 $this->$var=$value;
 else {
 $this->error(__FUNCTION__,$var." does not belong to PB_Page!");
 }
 }
 /**
 * Turn on inverted AJAX mode
 *
 * @ param string $action Default ajax triggered action.
  */
 function open_ajax($action)
 {
  $this->is_ajax=true;
  $this->ajax_action_name=$action;
 }
 /**
 * Get the code to display "next page"
 *
 * @param string $style
 * @return string
*/
 function next_page($style='')
 {
  if($this->nowindex<$this->totalpage){
   return $this->_get_link($this->_get_url($this->nowindex+1),$this->next_page,$style);
  }
  return ''.$this->next_page.'';
 }
 /**
 * Get the code to display "previous page"
 *
 * @param string $style
 * @return string
*/
 function pre_page($style='')
 {
  if($this->nowindex>1){
   return $this->_get_link($this->_get_url($this->nowindex-1),$this->pre_page,$style);
  }
  return ''.$this->pre_page.'';
 }
 /**
 * Get the code to display "Home Page"
 *
 * @return string
*/
 function first_page($style='')
 {
  if($this->nowindex==1){
      return ''.$this->first_page.'';
  }
  return $this->_get_link($this->_get_url(1),$this->first_page,$style);
 }
 /**
 * Get the code to display the "last page"
 *
 * @return string
*/
 function last_page($style='')
 {
  if($this->nowindex==$this->totalpage){
      return ''.$this->last_page.'';
  }
  return $this->_get_link($this->_get_url($this->totalpage),$this->last_page,$style);
 }
 function nowbar($style='',$nowindex_style='c')
 {
  $plus=ceil($this->pagebarnum/2);
  if($this->pagebarnum-$plus+$this->nowindex>$this->totalpage)$plus=($this->pagebarnum-$this->totalpage+$this->nowindex);
  $begin=$this->nowindex-$plus+1;
  $begin=($begin>=1)?$begin:1;
  $return='';
  for($i=$begin;$i<$begin+$this->pagebarnum;$i++)
  {
   if($i<=$this->totalpage){
    if($i!=$this->nowindex)
        $return.=$this->_get_text($this->_get_link($this->_get_url($i),$i,$style));
    else
        $return.=$this->_get_text(''.$i.'');
   }else{
    break;
   }
   $return.="n";
  }
  unset($begin);
  return $return;
 }
 /**
 * Get the code to display the jump button
 *
 * @return string
*/
 function select()
 {
   $return='';
  for($i=1;$i<=$this->totalpage;$i++)
  {
   if($i==$this->nowindex){
    $return.=''.$i.'';
   }else{
    $return.=''.$i.'';
   }
  }
  unset($i);
  $return.='';
  return $return;
 }
 /**
 * Get the value required for limit in the mysql statement
 *
 * @return string
*/
 function offset()
 {
  return $this->offset;
 }
 /**
  * 控制分页显示风格（你可以增加相应的风格）
  *
  * @param int $mode
  * @return string
  */
 function show($mode=1)
 {
  switch ($mode)
  {
   case '1':
    $this->next_page='下一页';
    $this->pre_page='上一页';
    return $this->pre_page().$this->nowbar().$this->next_page().'第'.$this->select().'页';
    break;
   case '2':
    $this->next_page='下一页';
    $this->pre_page='上一页';
    $this->first_page='首页';
    $this->last_page='尾页';
    return $this->first_page().$this->pre_page().'[第'.$this->nowindex.'页]'.$this->next_page().$this->last_page().'第'.$this->select().'页';
    break;
   case '3':
    $this->next_page='下一页';
    $this->pre_page='上一页';
    $this->first_page='首页';
    $this->last_page='尾页';
    return $this->first_page().$this->pre_page().$this->next_page().$this->last_page();
    break;
   case '4':
    $this->next_page='>';
    $this->pre_page='<';
    $this->first_page='<<';
    $this->last_page='>>';
    return $this->first_page().$this->pre_page().$this->nowbar().$this->next_page().$this->last_page();
    break;
   case '5':
    return $this->pre_bar().$this->pre_page().$this->nowbar().$this->next_page().$this->next_bar();
    break;
  }
 }
/*----------------private function (私有方法)-----------------------------------------------------------*/
 /**
  * 设置url头地址
  * @param: String $url
  * @return boolean
  */
 function _set_url($url="")
 {
  if(!empty($url)){
      //手动设置
   $this->url=$url;
  }else{
      //自动获取
   if(empty($_SERVER['QUERY_STRING'])){
       //不存在QUERY_STRING时
    $this->url=$_SERVER['REQUEST_URI']."?".$this->page_name."=";
   }else{
       //
    if(stristr($_SERVER['QUERY_STRING'],$this->page_name.'=')){
        //地址存在页面参数
     $this->url=str_replace($this->page_name.'='.$this->nowindex,'',$_SERVER['REQUEST_URI']);
     $last=$this->url[strlen($this->url)-1];
     if($last=='?'||$last=='&'){
         $this->url.=$this->page_name."=";
     }else{
         $this->url.='&'.$this->page_name."=";
     }
    }else{
        //
     $this->url=$_SERVER['REQUEST_URI'].'&'.$this->page_name.'=';
    }//end if
   }//end if
  }//end if
 }
 /**
  * 设置当前页面
  *
  */
 function _set_nowindex($nowindex)
 {
  if(empty($nowindex)){
   //系统获取
   if(isset($_GET[$this->page_name])){
    $this->nowindex=intval($_GET[$this->page_name]);
   }
  }else{
      //手动设置
   $this->nowindex=intval($nowindex);
  }
 }
 /**
  * 为指定的页面返回地址值
  *
  * @param int $pageno
  * @return string $url
  */
 function _get_url($pageno=1)
 {
  return $this->url.$pageno . '.html';
 }
 /**
  * 获取分页显示文字，比如说默认情况下_get_text('1')将返回[1]
  *
  * @param String $str
  * @return string $url
  */
 function _get_text($str)
 {
  return $this->format_left.$str.$this->format_right;
 }
 /**
   * 获取链接地址
 */
 function _get_link($url,$text,$style=''){
  $style=(empty($style))?'':'class="'.$style.'"';
  if($this->is_ajax){
      //如果是使用AJAX模式
   return ''.$text.'';
  }else{
   return ''.$text.'';
  }
 }
 /**
   * 出错处理方式
 */
 function error($function,$errormsg)
 {
     die('Error in file '.__FILE__.' ,Function '.$function.'() :'.$errormsg);
 }
}
?>