Question

求大神帮忙注释一下php代码，越详细越好

public function download() {
$this->_layout = 'null';
$file_name =ParamHolder::get('file_name', '0');
if(MOD_REWRITE=='3'){
include(P_INC.'/custom.php');
$_path=strtolower(ParamHolder::get('_path', ''));
$arr = explode("-",$_path);

$dw_id = intval($arr[1]);
}else{
$dw_id =ParamHolder::get('dw_id', '0');
}
if (intval($dw_id) == 0) {
$this->assign('json',Toolkit::jsonERR(__('Invalid ID!')));
return '_error';
}
$curr_locale = trim(SessionHolder::get('_LOCALE'));
$user_role =trim(SessionHolder::get('user/s_role', '{guest}'));
try {
$now = time();
$o_dw = new Download();
if (!ACL::isRoleAdmin()){
$curr_dw =&$o_dw->find("`id`=? AND "
."((`pub_start_time`<? AND `pub_end_time`>=?) OR "
."(`pub_start_time`<? AND `pub_end_time`='-1') OR "
."(`pub_start_time`='-1' AND `pub_end_time`>=?) OR "
."(`pub_start_time`='-1' AND `pub_end_time`='-1')) AND "
."published='1' AND for_roles LIKE ? AND s_locale=?",
array($dw_id,$now, $now, $now, $now, '%'.$user_role.'%', $curr_locale));
} else {
$curr_dw =&$o_dw->find("`id`=? AND "
."((`pub_start_time`<? AND `pub_end_time`>=?) OR "
."(`pub_start_time`<? AND `pub_end_time`='-1') OR "
."(`pub_start_time`='-1'AND `pub_end_time`>=?) OR "
."(`pub_start_time`='-1' AND `pub_end_time`='-1')) AND "
."published='1' AND s_locale=?",
array($dw_id,$now, $now, $now, $now, $curr_locale));
}
if(sizeof($curr_dw) <=0) {
$this->assign('json', Toolkit::jsonERR(__('Invalid ID!')));
return '_error';
}
} catch (Exception $ex) {
$this->assign('json',Toolkit::jsonERR($ex->getMessage()));
return '_error';
}
if(!file_exists(ROOT.'/upload/file/'.$curr_dw->name)) {
$this->assign('json',Toolkit::jsonERR(__('File does not exist!')));
return '_error';
}
include_onceP_LIB."/download.php";
$o_filedownload = newfile_download();
$o_filedownload->downloadfile(ROOT.'/upload/file/'.$curr_dw->name);
//$this->file_download(ROOT.'/upload/file/'.$curr_dw->name);
}

Answer 1

//定义一个public的成员函数download
public function download() {
        $this->_layout = 'null';   //给成员变量赋值
        $file_name =ParamHolder::get('file_name', '0');  //调用ParamHolder的静态方法get来获取filename，具体没有代码无法得知如何处理
               if(MOD_REWRITE=='3'){  //判断MOD_REWRITE宏
             include(P_INC.'/custom.php');  包含custom.php文件
             $_path=strtolower(ParamHolder::get('_path', ''));  同上获取_path参数并转换成小写
             $arr = explode("-",$_path);  //使用-吧$_path分割成数组
       
             $dw_id = intval($arr[1]);  //吧数组的第二个元素转换成int类型
        }else{
        $dw_id =ParamHolder::get('dw_id', '0');  //同上获取dw_id参数  
              }
        if (intval($dw_id) == 0) {  //转换dw_id为int类型然后判断是否等于0
            $this->assign('json',Toolkit::jsonERR(__('Invalid ID!')));  //这个应该是用了什么框架的模板来输出json内容
            return '_error';  
        }
        $curr_locale = trim(SessionHolder::get('_LOCALE'));  //获取SESSION中的_LOCALE值，并去除空格
        $user_role =trim(SessionHolder::get('user/s_role', '{guest}'));  //获取SESSION中的user/s_role，然后去除空格，默认为{guest}
        try {  //try 来捕获异常
             $now = time();  //获取当前时间
            $o_dw = new Download();    //新建一个Download类，没有具体代码无法知道内容
            if (!ACL::isRoleAdmin()){   //根据命名来来猜测， 判断当前用户是否是Admin
                $curr_dw =&$o_dw->find("`id`=? AND "
                           ."((`pub_start_time`<? AND `pub_end_time`>=?) OR "
                           ."(`pub_start_time`<? AND `pub_end_time`='-1') OR "
                           ."(`pub_start_time`='-1' AND `pub_end_time`>=?) OR "
                           ."(`pub_start_time`='-1' AND `pub_end_time`='-1')) AND "
                           ."published='1' AND for_roles LIKE ? AND s_locale=?",
                        array($dw_id,$now, $now, $now, $now, '%'.$user_role.'%', $curr_locale));  //执行一个SQL查找语句 具体作用可能是查找dw_id是否存在
            } else {
                $curr_dw =&$o_dw->find("`id`=? AND "
                           ."((`pub_start_time`<? AND `pub_end_time`>=?) OR "
                           ."(`pub_start_time`<? AND `pub_end_time`='-1') OR "
                            ."(`pub_start_time`='-1'AND `pub_end_time`>=?) OR "
                           ."(`pub_start_time`='-1' AND `pub_end_time`='-1')) AND "
                           ."published='1' AND s_locale=?",
                        array($dw_id,$now, $now, $now, $now, $curr_locale));  //同上
            }
            if(sizeof($curr_dw) <=0) {  //判断$curr_dw的大小是否小于等于0
               $this->assign('json', Toolkit::jsonERR(__('Invalid ID!')));  //使用模板来输出个json内容
                return '_error';
            }
        } catch (Exception $ex) {  //捕获异常
            $this->assign('json',Toolkit::jsonERR($ex->getMessage())); //使用json来输出捕获的异常
            return '_error';
        }
        if(!file_exists(ROOT.'/upload/file/'.$curr_dw->name)) {  //判断从数据库中取到的信息的name拼接成一个路径判断是否存在
            $this->assign('json',Toolkit::jsonERR(__('File does not exist!')));  //同上
            return '_error';
        }
              include_once P_LIB."/download.php";  //包含download.php文件
              $o_filedownload = newfile_download();  //无法得知newfile_download函数具体内容
              $o_filedownload->downloadfile(ROOT.'/upload/file/'.$curr_dw->name)
           ; //上下文猜测可能是把表单传递过来的file移动到指定目录里。
       //$this->file_download(ROOT.'/upload/file/'.$curr_dw->name);
    }