php自适应分页类

<?php
/*
*@Author: ray
*@E-mail: [email protected]
*@Date: 2016-3-29
*@Explain: 自适应分页类
**/

class Page {
    public $total;//总记录
    public $pageSize;//每页大小
    public $page;//当前页
    public $pages;//总页数
    public $link;//显示的页码数   1 2 3 4 5 6
    public $left;//显示页码的左边数目
    public $right;//显示页码的右边数目
    public $pageId;//传值的变量名
    public $prev;//上一页
    public $next;//下一页
    public $GP;//传值的方式  GET/POST
    public $start;//中间显示页码的开始页码数
    public $end;//中间显示页码的结束页码数
    
    //渲染主题
    public $theme=array('first','prev','link','next','last','total','info');
    
    //构造方法
    public function __construct($num, $pageSize, $link=7, $pageId='page', $GP='G'){
        $this->total=$num;
        $this->pageSize=$pageSize;
        $this->link=$link;
        $this->pageId=$pageId;
        $this->GP=$GP;
        
        $this->rule();
    }
    
    
    //计算页码
    public function rule(){
        //计算总页数
        $this->pages=ceil($this->total/$this->pageSize);
        
        //获得当前页
        if($this->GP=='G'){//GET
            $this->page=isset($_GET[$this->pageId])?$_GET[$this->pageId]:1;
        }else{//POST
            $this->page=isset($_POST[$this->pageId])?$_POST[$this->pageId]:1;
        }
        //约束当前页边界
        $this->constraint();
        
        //上下页
        $this->prev=$this->page-1;
        $this->next=$this->page+1;
        
        //计算中间页码的开始和结束的页码数
        //计算左右显示的页码数
        if($this->link%2){//link为奇数
            $this->left=$this->right=($this->link-1)/2;
        }else{//link为偶数
            $this->left=$this->link/2;
            $this->right=$this->link-$this->left-1;
        }
        //初始化
        $this->start=1;
        $this->end=$this->pages;
        
        if($this->pages>$this->link){
            //1.起始页为1
            if($this->page<=$this->left){
                $this->end=$this->link;
            }
            //2.中间
            if(($this->page>$this->left) && (($this->page+$this->right)<$this->pages)){
                $this->start=$this->page-$this->left+1;
                $this->end=$this->page+$this->right-1;
            }
            //3.结束页为pages
            if(($this->page+$this->right)>=$this->pages){
                $this->start=$this->pages-$this->link+1;
            }
        }
        
    }
    
    
    //边界约束
    public function constraint(){
        if($this->page<1) $this->page=1;
        if($this->page>$this->pages) $this->page=$this->pages;
    }
    
    //获取当前页面的url
    public function getUrl(){
        return "http://".$_SERVER['HTTP_HOST'].($_SERVER['SERVER_PORT']!='80'?(':'.$_SERVER['SERVER_PORT']):'').$_SERVER['PHP_SELF'];
    }
    
    //获取limit
    public function getLimit(){
        return ($this->page-1)*$this->pageSize;
    }
    
    //改变主题
    public function changeTheme(array $theme){
        $this->theme=$theme;
    }
    
    //渲染页码   <a>  <span name='now'>
    public function show(array $arr=array()){
        if(!count($arr)){
            $arr=$this->theme;
        }
        $url=$this->getUrl();
        //首页、上一页约束
        if($this->page==1){
            $html['first']="<span>首页</span>";
            $html['prev']="<span>上一页</span>";
            
        }else{
            $html['first']="<a href='".$url."?".$this->pageId."=1'>首页</a>";
            $html['prev']="<a href='".$url."?".$this->pageId."=".$this->prev."'>上一页</a>";
            
        }
        
        $str='';
        //起始点页码
        if($this->start!=1){
            $str='<span>...</span>';
        }
        
        for($i=$this->start;$i<=$this->end;$i++){
            if($i==$this->page){
                $str.="<span name='now'>$i</span>";
                continue;
            }
            $str.="<a href='".$url."?".$this->pageId."=".$i."'>$i</a>";
        }
        //结束点页码
        if($this->end!=$this->pages){
            $str.='<span>...</span>';
        }
        
        $html['link']=$str;
        
        //下一页、末页约束
        if($this->page==$this->pages){
            $html['next']="<span>下一页</span>";
            $html['last']="<span>末页</span>";
            
        }else{
            $html['next']="<a href='".$url."?".$this->pageId."=".$this->next."'>下一页</a>";
            $html['last']="<a href='".$url."?".$this->pageId."=".$this->pages."'>末页</a>";
            
        }
        $html['total']="共有".$this->total."条结果 ";
        $html['info']="当前为第".$this->page."/".$this->pages."页";
        
        $res='';
        foreach($arr as $v){
            $res.=$html[$v];
        }
        return $res;
    }
}