Example of function for generating page-turning link list in PHP

/**
 * Generate page number list
 * @param int $element_total_count Total number of elements
 * @param int $current_page Current page
 * @param int $per_page_elem_count Number of elements per page
 * @param int $show_page_num Number of page numbers displayed in the list
 * @param string $up_down_class Up and down page turning style
 * @param string $num_class current page number style
 * @param string $href page link
 * @param string $page_symbol link parameter passing the page number
 * @return string
 * @site bbs.it-home.org
*/
public static function getPageListLink($element_total_count,$current_page=1,$per_page_elem_count=10,
    $show_page_num=10,$up_down_class='',$num_class='',$href='',$page_symbol='p')
{
    if(empty($href)) {
        //自动取得剔除页码参数的页面链接
        $page_name = basename($_SERVER['PHP_SELF']);
        $params = $_SERVER['QUERY_STRING'];
        $params_str = '';
        if(!empty($params)) {
            $params = str_replace('&', '&', $params);
            $params_array = explode('&', $params);
            foreach($params_array as $param) {
                if(!empty($param)) {
                    $index = strpos($param, '=');
                    if($index) {
                        $key = substr($param, 0, $index);
                        if($key && $key != $page_symbol)
                            $params_str .= $param . '&';
                    }
                }
            }
        }
        if(!empty($params_str))
            $href = $page_name . '?' . $params_str;
        else
            $href = $page_name;
        $href = rtrim($href,'&');
    }
    $prefix = strpos($href,"?") ? "&" : "?";
    $prefix .= $page_symbol;
    $page_total_count = ceil($element_total_count/$per_page_elem_count);
    if(intval($element_total_count)< 1 || !isset($element_total_count)) {
        return '';
    }
    if($element_total_count <= $per_page_elem_count)
        return '';
    if($current_page>$page_total_count)
        $current_page = 1;
    if(strpos($href,"#")) {
        $label = substr($href,strpos($href,"#"));
        $href = substr($href,0,strpos($href,"#"));
    }
    /* 生成页码 */
    if($current_page > ceil($show_page_num/2)) {
        $start = $current_page - ceil($show_page_num/2);
        $end = (($current_page+ceil($show_page_num/2))<$page_total_count) ?
            $current_page+ceil($show_page_num/2)-1 : $page_total_count;
    } else {
        $start = 1;
        $end = ($show_page_num>$page_total_count) ? $page_total_count : $show_page_num;
    }
    if(!empty($num_class))
        $num_class_str = ' class="'.$num_class.'"';
    else
        $num_class_str = '';
    $page_num_string = '';
    for($i=$start;$i<=$end;$i++) {
        if(intval($i) == intval($current_page))
            $page_num_string .= ''.$i.'';
        else
            $page_num_string .= ''.$i.'';
    }
    /* 上下翻页 */
    $prev_page = (intval($current_page-1)>0)?intval($current_page-1):0;
    $next_page = (intval($current_page)<$page_total_count) ? intval($current_page+1) : 0;
    if(!empty($up_down_class))
        $up_down_class_str = ' class="'.$up_down_class.'"';
    else
        $up_down_class_str = '';
    $page_up_string = '';
    if(intval($prev_page) > 0)
        $page_up_string = '上一页';
    else
        $page_up_string = '上一页';
    $page_down_string = '';
    if(intval($next_page) > 0)
        $page_down_string .= '下一页';
    else
        $page_down_string .= '下一页';
    return $page_up_string . $page_num_string . $page_down_string;
}