来自php脚本的Json响应不起作用

Question

I'm building a form to upload images and other data and I want it to return json validation or success response via the ajax success function.

Problem is the php script seems to do some of the if statements, but then completely ignores the extensions validation statement and the file size validation.

I have a switch/case statement in the AJAX to handle the json response from the php script. the switch/case statement then shows the respective message and then fades out.

note: No errors were found in the console.

Thank you for any help.

AJAX:

$(document).ready(function (e) {
    $('.add_business_form').on('submit',(function(e) {  

        e.preventDefault();

        var formData = new FormData(this);


        $.ajax({
            type:'POST',
            url: $(this).attr('action'),
            data:formData,
            cache:false,
            contentType: false,
            processData: false,
            dataType: "json",
            success:function(response){

    switch(response.message){
      case 'logo_success': 
         logoSuccess();
      break;
      case 'file_is_not_image': 
        file_is_not_image();
      break;
      case 'No_file_selected': 
        No_file_selected();
      break;        

      case 'wrong_logo_extention':
        Wrong_extention();
      break;        
       case 'logo_too_big':
        logo_too_big();
      break;
       case 'unknown_error':
        unknown_error();
      break;
    }           

            },
            error: function(data){   


            }
        });
    }));

}); 

jQuery functions(to handle ajax response):

<script>
 function logoSuccess(){
 $('.response_success').fadeIn('fast').delay(10000).fadeOut('fast');    
$('.add_business_form')[0].reset();  
 }      
</script>   
<script>
 function file_is_not_image(){
 $('.file_is_not_image').fadeIn('fast').delay(10000).fadeOut('fast');    
 }      
</script>
<script>
 function No_file_selected(){
 $('.No_file_selected').fadeIn('fast').delay(10000).fadeOut('fast');         
 }      
</script>
<script>
 function logo_too_big(){
 $('.logo_too_big').fadeIn('fast').delay(10000).fadeOut('fast');         
 }      
</script>
<script>
 function unknown_error(){
 $('.unknown_error').fadeIn('fast').delay(10000).fadeOut('fast');        
 }      
</script>

PHP script

if(empty($_FILES['uploaded_img_preview']['name'])){
    $response["message"] = 'No_file_selected';
}else{

$imgFile = $_FILES['uploaded_img_preview']['name'];
$tmp_dir = $_FILES['uploaded_img_preview']['tmp_name'];
$imgSize = $_FILES['uploaded_img_preview']['size'];
$imgExt = strtolower(pathinfo($imgFile,PATHINFO_EXTENSION));
$upload_dir = '../images/'; // upload directory


   // valid image extensions
   $valid_extensions = array('jpg','png','jpeg'); // valid extensions

   // rename uploading image
   $new_logo_name = rand(1000,1000000).".".$imgExt;

   // allow valid image file formats
   if(in_array($imgExt, $valid_extensions)){   
    // Check file size '5MB'
    if($imgSize < 500000)    {

    }
    else{
     $response["message"] = 'logo_too_big';
    }
   }
   else{
     $response["message"] = 'wrong_logo_extention';  
   }

    if (move_uploaded_file($tmp_dir,$upload_dir.$new_logo_name)){
     $response["message"] = 'logo_success'; 
    }else{
    $response["message"] = 'unknown_error'; 

    }
 }

echo json_encode($response);
exit();

Answer 1

The reason that the images are uploading when, the file size is large and also when the ext is wrong, is simple because, you are allowing your script to upload even if the errors exists, what you need is to have an error counter variable so that when the error occurs you increment the variable then only upload the image when the error counter is zero

here how :

<?php

$errors = "";//Count error
if (empty($_FILES['uploaded_img_preview']['name'])) {
    $response["message"] = 'No_file_selected';
} else {

    $imgFile    = $_FILES['uploaded_img_preview']['name'];
    $tmp_dir    = $_FILES['uploaded_img_preview']['tmp_name'];
    $imgSize    = $_FILES['uploaded_img_preview']['size'];
    $imgExt     = strtolower(pathinfo($imgFile, PATHINFO_EXTENSION));
    $upload_dir = '../images/'; // upload directory


    if ($imgExt != "jpg" && $imgExt != "png" && $imgExt != "jpeg" && $imgExt != "gif") {
        $response["message"] = 'wrong_logo_extention';

        $errors++; //increment
    }

    if ($imgSize > 500000) {

        $response["message"] = 'logo_too_big';
        $errors++; //increment
    }
    // rename uploading image
    $new_logo_name = rand(1000, 1000000) . "." . $imgExt;

    //upload only if there are no errors
    if ($errors <= 0) {

        if (move_uploaded_file($tmp_dir, $upload_dir . $new_logo_name)) {
            $response["message"] = 'logo_success';
        } else {
            $response["message"] = 'unknown_error';

        }

    }


}

echo json_encode($response);
exit();
?>