php - Ajax成功函数不输出Php脚本发送的文本

Question

我正在使用下面的 PHP 脚本上传多个文件:

<?php

if(isset($_FILES['uploadfile'])){
    $total_files = count($_FILES['uploadfile']['name']);
    if( $total_files > 0){

        for($i=0; $i<$total_files; $i++) {

            $file_name = $_FILES['uploadfile']['name'][$i];
            $file_size = $_FILES['uploadfile']['size'][$i];
            $file_tmp  = $_FILES['uploadfile']['tmp_name'][$i];
            $file_type = $_FILES['uploadfile']['type'][$i]; 

            $upload_Path = "storage/".$file_name;

            //var_dump($file_size); 
            //die; 

            if($file_size > 8000000){
                echo ('Total upload size must be less than 8 MB.');
                die;
            }   

            if($file_tmp == ""){
                echo ('There is no file path.');    
                die;    
            }
            else{
                if(!file_exists($upload_Path)){
                    move_uploaded_file($file_tmp, $upload_Path);
                }
                else{
                    $name = pathinfo($file_name, PATHINFO_FILENAME);
                    $ext  = pathinfo($file_name, PATHINFO_EXTENSION);
                    $new_name = $name.rand().'.'.$ext;

                    $new_Path = "storage/".$new_name;
                    move_uploaded_file($file_tmp, $new_Path);
                }
            }
        }
    }
    die('File uploaded successfully!');
}
?>

但问题是，每当发生诸如 echo ('总上传大小必须小于 8 MB.'); 之类的错误时，它都不会使用 ajax 输出。但上传成功后，会显示文件上传成功!。

我的AJAX如下:

$.ajax({
                type:'POST',
                url: 'mupld.php',
                data: formdata,
                processData:false,
                contentType:false,
                success: function(response){
                    alert('Success: '+response);
                },
                error: function(xhr, status, error){
                    alert('Error: '+status+' '+error);
                }
            });                     

在进行 var 转储时，对于上传超过 8mb 的文件，我没有得到任何输出，但对于低于 8mb 的文件，我得到了

Success: <pre class='xdebug-var-dump' dir='ltr'><small>int</small> <font color='#4e9a06'>3283515</font>
</pre>

Answer 1

@Jeff Bucket 是对的，所以我编辑了我的答案:

实际上，您应该在成功回调中处理这些错误。 error() 回调保留用于浏览器和服务器之间的连接刚刚中断的情况，并且 error() 参数期望处理此类情况，例如典型的 textStatus 错误应该是“未找到”或“内部服务器错误” ”，但没有“总上传大小必须小于 8 MB。”。

您应该返回一个包含可在客户端中使用的信息的数组，并在 success() 中处理它，例如:

尝试{

if(isset($_FILES['uploadfile'])){
    $total_files = count($_FILES['uploadfile']['name']);
    if( $total_files > 0){

        for($i=0; $i<$total_files; $i++) {

            $file_name = $_FILES['uploadfile']['name'][$i];
            $file_size = $_FILES['uploadfile']['size'][$i];
            $file_tmp  = $_FILES['uploadfile']['tmp_name'][$i];
            $file_type = $_FILES['uploadfile']['type'][$i];

            $upload_Path = "storage/".$file_name;

            //var_dump($file_size);
            //die;

            if($file_size > 8000000){
                echo json_encode( array('status' => 'failure'  , 'msg' => 'Total upload size must be less than 8 MB.')  );
                die();
            }

            if($file_tmp == ""){
                echo json_encode( array('status' => 'failure'  , 'msg' => 'There is no filepath.')  );
                die;
            }
            else{
                if(!file_exists($upload_Path)){
                    move_uploaded_file($file_tmp, $upload_Path);
                }
                else{
                    $name = pathinfo($file_name, PATHINFO_FILENAME);
                    $ext  = pathinfo($file_name, PATHINFO_EXTENSION);
                    $new_name = $name.rand().'.'.$ext;

                    $new_Path = "storage/".$new_name;
                    move_uploaded_file($file_tmp, $new_Path);
                }
            }
        }
    }
    echo json_encode( array('status' => 'success'  , 'msg' => 'File uploaded succesfully.')  );
    die();
}

else{

    echo json_encode(array("status" => "error" , "msg" => "No file was found when processing uploaded files" ) );
    die();
}


}
catch(Exception $ex){

echo json_encode(array('status' => 'error' , 'msg' => 'An unhandled exception raised: ' . $ex->getMessage() ) );
die();
}
finally{
    die();
}

然后在你的 $.ajax() 函数中:

$("#uploadfile").change(function(){ 
//submit the form here 
var files = $("#fileupload")[0]; 
var formdata = new FormData(files); 
$.ajax({ 
    type:'POST', 
    url: 'mupld.php', 
    data: formdata, 
    processData:false, 
    contentType:false, 
    success: function(response){ 

             response = JSON.parse(response);
             alert(response.msg);

        }, 
    error: function(xhr, textStatus, error){ 
        console.log('Error: '+textStatus+' '+error); 
    } 
}); 

如果您特别想在 error() 回调中处理此问题，则应使用 header() 将 php 脚本的响应代码设置为 500 - 或任何自定义代码。