tp5框架内使用tp3.2分页的方法分析

<?php
namespace org;//命名规范
class Page{
  public $firstRow; // 起始行数
  public $listRows; // 列表每页显示行数
  public $parameter; // 分页跳转时要带的参数
  public $totalRows; // 总行数
  public $totalPages; // 分页总页面数
  public $rollPage  = 7;// 分页栏每页显示的页数
  public $lastSuffix = false; // 最后一页是否显示总页数
  private $p    = 'p'; //分页参数名
  private $url   = ''; //当前链接URL
  private $nowPage = 1;
  // 分页显示定制
  private $config = array(
    'header' => '<span class="rows">共 %TOTAL_ROW% 条记录</span>',
    'prev'  => '<<',
    'next'  => '>>',
    'first' => '1...',
    'last'  => '...%TOTAL_PAGE%',
    'theme' => '%FIRST% %UP_PAGE% %LINK_PAGE% %DOWN_PAGE% %END%',
  );
  /**
   * 架构函数
   * @param array $totalRows 总的记录数
   * @param array $listRows 每页显示记录数
   * @param array $parameter 分页跳转的参数
   */
  public function __construct($totalRows, $listRows=20, $parameter = array()) {
    config('var_page') && $this->p = config('var_page'); //设置分页参数名称
    /* 基础设置 */
    $this->totalRows = $totalRows; //设置总记录数
    $this->listRows  = $listRows; //设置每页显示行数
    $this->parameter = empty($parameter) ? input('param.'):$parameter;//因为tp5无法直接获取到$_GET,所以这里直接拿tp5的函数input('param.'),下面的一样
    $this->nowPage  = empty(input('param.p')) ? 1 : intval(input('param.p'));
    $this->nowPage  = $this->nowPage>0 ? $this->nowPage : 1;
    $this->firstRow  = $this->listRows * ($this->nowPage - 1);
  }
  /**
   * 定制分页链接设置
   * @param string $name 设置名称
   * @param string $value 设置值
   */
  public function setConfig($name,$value) {
    if(isset($this->config[$name])) {
      $this->config[$name] = $value;
    }
  }
  /**
   * 生成链接URL
   * @param integer $page 页码
   * @return string
   */
  private function url($page){
    $ispage = str_replace(urlencode('[PAGE]'), $page, $this->url);
    return $ispage;
  }
  /**
   * 组装分页链接
   * @return string
   */
  public function show() {
    if(0 == $this->totalRows) return '';
    /* 生成URL */
    $this->parameter[$this->p] = '[PAGE]';
    $this->url = url(request()->action(), $this->parameter);//生成url改成tp5获取当前action的
    /* 计算分页信息 */
    $this->totalPages = ceil($this->totalRows / $this->listRows); //总页数
    if(!empty($this->totalPages) && $this->nowPage > $this->totalPages) {
      $this->nowPage = $this->totalPages;
    }
    /* 计算分页临时变量 */
    $now_cool_page   = $this->rollPage/2;
    $now_cool_page_ceil = ceil($now_cool_page);
    $this->lastSuffix && $this->config['last'] = $this->totalPages;
    //上一页
    $up_row = $this->nowPage - 1;
    $up_page = $up_row > 0 ? '<a class="prev" href="' . $this->url($up_row) . '" rel="external nofollow" >' . $this->config['prev'] . '</a>' : '';
    //下一页
    $down_row = $this->nowPage + 1;
    $down_page = ($down_row <= $this->totalPages) ? '<a class="next" href="' . $this->url($down_row) . '" rel="external nofollow" >' . $this->config['next'] . '</a>' : '';
    //第一页
    $the_first = '';
    if($this->totalPages > $this->rollPage && ($this->nowPage - $now_cool_page) >= 1){
      $the_first = '<a class="first" href="' . $this->url(1) . '" rel="external nofollow" >' . $this->config['first'] . '</a>';
    }
    //最后一页
    $the_end = '';
    if($this->totalPages > $this->rollPage && ($this->nowPage + $now_cool_page) < $this->totalPages){
      $the_end = '<a class="end" href="' . $this->url($this->totalPages) . '" rel="external nofollow" >' . $this->config['last'] . '</a>';
    }
    //数字连接
    $link_page = "";
    for($i = 1; $i <= $this->rollPage; $i++){
      if(($this->nowPage - $now_cool_page) <= 0 ){
        $page = $i;
      }elseif(($this->nowPage + $now_cool_page - 1) >= $this->totalPages){
        $page = $this->totalPages - $this->rollPage + $i;
      }else{
        $page = $this->nowPage - $now_cool_page_ceil + $i;
      }
      if($page > 0 && $page != $this->nowPage){
        if($page <= $this->totalPages){
          $link_page .= '<a class="num" href="' . $this->url($page) . '" rel="external nofollow" >' . $page . '</a>';
        }else{
          break;
        }
      }else{
        if($page > 0 && $this->totalPages != 1){
          $link_page .= '<span class="current">' . $page . '</span>';
        }
      }
    }
    //替换分页内容
    $page_str = str_replace(
      array('%HEADER%', '%NOW_PAGE%', '%UP_PAGE%', '%DOWN_PAGE%', '%FIRST%', '%LINK_PAGE%', '%END%', '%TOTAL_ROW%', '%TOTAL_PAGE%'),
      array($this->config['header'], $this->nowPage, $up_page, $down_page, $the_first, $link_page, $the_end, $this->totalRows, $this->totalPages),
      $this->config['theme']);
    return "<div>{$page_str}</div>";
  }
}