分页类尾部页码导航

<?php
/**
 * 生成Comment的尾部分页导航
 * @author 李俊
 *
 */
class cmtTail{
    private $currentPage;
    private $totalPage;
     
    /**
     * 生成页码导航--总控函数
     * @param string $currentPage 当前页码
     * @param string $totalPage 总页数
     * @throws Exception 页码小于1将会抛出异常
     * @return string
     */
    function __do($currentPage, $totalPage) {
        $this->currentPage=$currentPage;
        $this->totalPage=$totalPage;
        if($this->totalPage<=10){//总页数小于等于10页
            if($this->currentPage==1){//当前页是第一页
                $str='上一页'.$this->currentTag();
                for ($i = 2; $i <= $this->totalPage; $i++) {
                    $str=$str.$this->commonTag($i);
                }
                $str=$str.$this->next();
            }elseif ($this->currentPage==$this->totalPage){//已跳至最后一页
                $str=$this->up();
                for ($i = 1; $i <= $this->totalPage-1; $i++) {
                    $str=$str.$this->commonTag($i);
                }
                $str=$str.$this->currentTag();
                $str=$str.$this->next();
            }else{
                $str=$this->up();
                for($i=1; $i<$this->currentPage; $i++){
                    $str=$str.$this->commonTag($i);
                }
                $str=$str.$this->currentTag();//生成当前页标签
                for ($i = $this->currentPage+1; $i <= $this->totalPage; $i++) {
                    $str=$str.$this->commonTag($i);
                }
                $str=$str.$this->next();
            }
        }elseif ($this->totalPage>10){//页码大于10
            if($this->currentPage==1){//8+2
                $str='上一页'.$this->currentTag();
                for ($i = 2; $i <= 8; $i++) {
                    $str=$str.$this->commonTag($i);
                }
                $str=$str.'...';//添加省略号
                $str=$str.$this->commonTag($this->totalPage-1);
                $str=$str.$this->commonTag($this->totalPage);
            }elseif($this->currentPage==$this->totalPage) {//当前为最后一页
                $str=$this->up();
                $str=$str.$this->commonTag(1);
                $str=$str.'...';//添加省略号
                for ($i = $this->totalPage-6; $i < $this->totalPage; $i++) {
                    $str=$str.$this->commonTag($i);
                }
                $str=$str.$this->currentTag();
                $str=$str.$this->next();
            }else {
                if ($this->currentPage<6) {
                    $str=$this->up();
                    for ($i = 1; $i < $this->currentPage; $i++) {
                        $str=$str.$this->commonTag($i);
                    }
                    $str=$str.$this->currentTag();
                    for ($i = $this->currentPage+1; $i <= 7; $i++) {
                        $str=$str.$this->commonTag($i);
                    }
                    $str=$str.'...';//添加省略号
                    $str=$str.$this->commonTag($this->totalPage);
                    $str=$str.$this->next();
                }else {
                    if ($this->currentPage>=$this->totalPage-4) {
                        $str=$this->up();
                        $str=$str.$this->commonTag(1);
                        $str=$str.'...';//添加省略号
                        for ($i = $this->totalPage-6; $i < $this->currentPage; $i++) {
                            $str=$str.$this->commonTag($i);
                        }
                        $str=$str.$this->currentTag();
                        for ($i = $this->currentPage+1; $i <= $this->totalPage; $i++) {
                            $str=$str.$this->commonTag($i);
                        }
                        $str=$str.$this->next();
                    }elseif ($this->currentPage<$this->totalPage-4){//1+5+1
                        $str=$this->up();
                        $str=$str.$this->commonTag(1);
                        $str=$str.'...';//添加省略号
                        $str=$str.$this->commonTag($this->currentPage-2);
                        $str=$str.$this->commonTag($this->currentPage-1);
                        $str=$str.$this->currentTag();
                        $str=$str.$this->commonTag($this->currentPage+1);
                        $str=$str.$this->commonTag($this->currentPage+2);
                        $str=$str.'...';//添加省略号
                        $str=$str.$this->commonTag($this->totalPage);
                        $str=$str.$this->next();
                    }
                };
            }
        }elseif ($this->totalPage<=0){
            throw new Exception("页面不可能小于1");
        }
        return $str;
    }
    /**
     * 一般标签
     * @param int $param 页码
     * @return string
     */
    function commonTag($param) {
        return '<a page="'.$param.'">'.$param.'</a>';
    }
    /**
     * 生成当前页标签
     * @param int $param 页码
     * @return string
     */
    function currentTag() {
        return '<strong id="on">'.$this->currentPage.'</strong>';
    }
    /**
     * 生成下一页标签
     * @param int $param 下一页页码
     * @return string
     */
    function next() {
        if ($this->currentPage==$this->totalPage) {
            return '下一页';
        }
        return '<a page="'.($this->currentPage+1).'">下一页</a>';
    }
    /**
     * 生成上一页标签
     * @param int $param 上一页页码
     * @return string
     */
    function up() {
        if ($this->currentPage==1){
            return '上一页';
        }else{
            return '<a page="'.($this->currentPage-1).'">上一页</a>';
        }
    }
    /**
     * 实例化cmtTail,
     * 功能：生成Comment的尾部分页导航
     * @param string $currentPage 当前页码
     * @param string $totalPage 总页数
     * @return string 返回html标签字符串
     */
    static function GO($currentPage, $totalPage) {
        $p=new cmtTail();
        return $p->__do($currentPage, $totalPage);
    }
}