自定义MVC框架之工具类-分页类的封装

以前写过一个MVC框架，封装的有点low，经过一段时间的沉淀，打算重新改造下，之前这篇文章封装过一个验证码类。

这次重新改造MVC有几个很大的收获

>全部代码都是用Ubuntu+Vim编写，以前都是windows上开发，这次彻底迷上Ubuntu Linux

>裸装php，用php自带的服务器解释执行php，缺哪个扩展就装哪个，最后通过整个MVC框架的开发，把Lamp所有的常用配置与细节搞懂

>通过扩展安装，学习扩展开发与php底层源码分析

总之，终于感觉层次又提升了不少。

分页类代码：

 <?php

 class Page {
     //每页显示的条目
     protected $pageSize;
     //总记录数
     protected $totalRecord;
     //当前页
     protected $p;
     //总页数
     protected $totalPage;
     protected $url;

     public function __construct( $_pageSize, $_totalRecord ){
         $this->pageSize = $_pageSize;
         $this->totalRecord = $_totalRecord;
         $this->totalPage = ceil( $this->totalRecord / $this->pageSize );
         $this->p = $this->getCurPage();
         $this->url = $this->getUrl();
     }

     public function setUrl( $p ){
         if( strstr( $this->url, '?' ) ) {
             //url中有参数
             $url = $this->url . '&p=' . $p;
         }else {
             //url中没有参数
             $url = $this->url . '?p=' . $p;
         }
         return $url;
     }

     //首页
     public function firstPage(){
         return $this->setUrl( 1 );
     }

     //末页
     public function lastPage(){
         return $this->setUrl( $this->totalPage );
     }

     //上一页
     public function prevPage(){
         if( $this->p - 1 <= 0 ) {
             $prevPage = $this->p;
         }else {
             $prevPage = $this->p - 1;
         }
         return $this->setUrl( $prevPage );
     }

     //下一页
     public function nextPage(){
         if( $this->p + 1 > $this->totalPage ) {
             $nextPage = $this->p;
         }else {
             $nextPage = $this->p + 1;
         }
         return $this->setUrl( $nextPage );
     }

     //得到当前的页码
     public function getCurPage(){
         $curPage = intval( $_GET['p'] );
         if ( empty( $curPage ) ) {
             $curPage = 1;
         }else if ( $curPage > $this->totalPage ) {
             $curPage = $this->totalPage;
         }else if ( $curPage < 0 ){
             $curPage = 1;
         }
         return $curPage;
     }

     //拼接url
     public function getUrl(){
         $protocol = strtolower( array_shift( explode( '/', $_SERVER['SERVER_PROTOCOL'] ) ) );
         $host = $_SERVER['SERVER_NAME'];
         $port = $_SERVER['SERVER_PORT'];
         $uri = $_SERVER['REQUEST_URI'];
         $uriArr = parse_url( $uri );
         $path = $uriArr['path'];
         if( !empty( $uriArr['query'] ) ) {
             //url中的query字符转数组
             parse_str( $uriArr['query'], $args );
             //清除原来的分页参数p
             if( isset( $args['p'] ) ){
                 unset( $args['p'] );
             }
             //参数重新拼接成字符串
             $queryString = http_build_query( $args );
             //字符串如果不止一个p参数,把那些参数拼接在path的后面
             if ( !empty( $queryString ) ){
                 $path .= '?' . $queryString;
             }
         }
         return $protocol . '://' . $host . ':' . $port . $path;
     }

     public function render(){
         return [
             'first' => $this->firstPage(),
             'last' => $this->lastPage(),
             'prev' => $this->prevPage(),
             'next' => $this->nextPage()
         ];
     }

     public function limit(){
         $offset = ( $this->p - 1 ) * $this->pageSize;
         return $offset . ',' . $this->pageSize;
     }
 }

 $page = new Page( 5, 11 );
 //echo $page->getCurPage();
 //echo $page->getUrl();
 print_r( $page->render() );

 ?>