PHP分页

<?php

$page=new Page(5,60);
var_dump($page->allUrl());

class Page{
///每页显示多少条数据
protected $number;
///一共有多少条数据
protected $totalCount;
///当前页
protected $page;
///总页数
protected $totalPage;
//// url
protected $url;

public function __construct($number,$totalCount){
$this->number=$number;
$this->totalCount=$totalCount;
/// 得到总页数
$this->totalPage=$this->getTotalPage();
/// 得到当前页数
$this->page=$this->getPage();
//// 得到url
$this->url=$this->getUrl();


}


protected function getTotalPage(){
return ceil($this->totalCount/$this->number);
}


protected function getPage(){
if(empty($_GET['page'])){
$page=1;
}else if($_GET['page']>$this->totalPage){
$page=$this->totalPage;
}else if($_GET['page']<1){
$page=1;
}else{
$page=$_GET['page'];
}
return $page;

}

protected function getUrl(){
/// 得到协议名
$scheme=$_SERVER['REQUEST_SCHEME'];
/// 得到主机名
$host=$_SERVER['SERVER_NAME'];
/// 得到端口号
$port=$_SERVER['SERVER_PORT'];
/// 得到路径和请求字符串
$uri=$_SERVER['REQUEST_URI'];


///// 中间做处理，要将page=5等这种字符串拼接到url中，所以如果原来url中有page这个参数，我们首先需要先将原来的page参数给清空

$uriArray=parse_url($uri);
$path=$uriArray['path'];
if(!empty($uriArray['query'])){
/// 首先将请求字符串变为关联数组

parse_str($uriArray['query'],$array);
/// 清除掉关联数组中的page键值对

unset($array['page']);
/// 将剩下的参数拼接为请求字符串

$query=http_build_query($array);
/// 再将请求的字符串拼接到路径的后面

if($query!=''){
$path=$path.'?'.$query;
}
}
return $scheme.'://'.$host.':'.$port.$path;

}


protected function setUrl($str){
if(strstr($this->url,'?')){
$url=$this->url.'&'.$str;
}else{
$url=$this->url.'?'.$str;
}
return $url;
}








public function allUrl(){
return [
'first'=> $this->first(),
'prev'=> $this->prev(),
'next'=> $this->next(),
'end'=> $this->end()

];

}

public function first(){
return $this->setUrl('page=1');
}

public function next(){
/// 根据当前page得到下一页的页码
if($this->page+1>$this->totalPage){
$page=$this->totalPage;
}else{
$page=$this->page+1;
}
return $this->setUrl('page='.$page);
}

public function prev(){
if($this->page-1<1){
$page=1;
}else{
$page=$this->page-1;
}
return $this->setUrl('page='.$page);
}

public function end(){
return $this->setUrl('page='.$this->totalPage);
}


public function limit(){
/// limit 0,5 limit 5,5
$offset=($this->page-1)*$this->number;
return $offset.','.$this->number;

}



}

?>