如何在ajax错误上显示文件上传错误消息？

Question

I'd like to display file upload error on an ajax alert error message.

This is my ajax:

$.ajax({
        url         : url,
        type        : 'POST',
        cache       : false,
        contentType : false,
        processData : false,
        data        : all_data,
        dataType    : 'JSON',
        success     : function(data)
        {
            if (data.result != 0) {
                toastr.options = {
                    closeButton : false,
                    progressBar : false,
                    showMethod  : 'slideDown',
                    timeOut     : 3000
                };

                toastr.success('UPLOAD SUCCESS', 'Attention...');

                if(activeid != 0){
                    if($("#tl_responder").val() != "" && $("#tl_dept").val() != "" && $("#tl_jawab").val() != ""){
                        toastr.success('MAIL IS SENT', 'ATTENTION...');
                    }
                }

            } else { window.location.href = "<?php print base_url(); ?>complaint/detail?id=" + data.result + "#reloadafteradd"; }

        },
        error: function (jqXHR, textStatus, errorThrown, data)
        {
            toastr.options = {
                closeButton : false,
                progressBar : false,
                showMethod  : 'slideDown',
                timeOut     : 3000
            };
            toastr.error(errorThrown, 'Error...'); //THIS IS THE AJAX ERROR ALERT
           if(!errorThrown){ toastr.error(data.upl_error, 'Error...'); }//This is not working

        }
    });

The AJAX error alert only shows alert when AJAX is not working. I'd like to display the file upload error here.

This is my controller that handle file upload when not uploading:

if ( ! $this->upload->do_upload('file')){

        $response_array = array ('upl_error' => $this->upload->display_errors());
        echo json_encode($response_array);
        //return false;
        }

Answer 1

You need to send a flag to specify if file uploaded successfully or not to do this send a success flag from your php code like this:

PHP CODE

if ( ! $this->upload->do_upload('file')){
    // file not  uploaded
    $response_array = array ('success'=0,'upl_error' =>   $this->upload->display_errors('', ''));
    echo json_encode($response_array);

}
else
{
  // file uploaded
   echo json_encode(array("success"=>1));
}

And then in your ajax success callback function you need to check that success flag like this

jQuery CODE

 $.ajax({
        url         : url,
        type        : 'POST',
        cache       : false,
        contentType : false,
        processData : false,
        data        : all_data,
        dataType    : 'JSON',
        success     : function(data)
        {
           // if file upload success
            if (data.success == 1) {

               alert("File uploaed success");

            } 
            // file not uploaded
            else { 
                alert(data.upl_error);
            }

        }
});

I hope it will help you.