无法使用AJAX在codeigniter中上传文件

Question

I'm trying to upload the file in CodeIgniter using Ajax but the problem is the file is uploading in the database but unable to do it without loading the page. Every time I upload a file it uploading successfully but navigating to its controller address with JSON code. I just want to upload the file without refreshing page.

View FILE

<?php echo form_open_multipart('maker/Checkout/docs', array('id'=>'upload_file')); ?>


          <div class="form-group">
              <label for="userfile">Upload existing CV</label>
              <input class="form-control" type="file" name="userfile" id="userfile" size="20" />
          </div>

          <div class="form-group">
            <button class="btn btn-info" type="submit">Upload</button>
          </div> 

       <?php echo form_close() ?> 

Ajax Code

<script>

  $(function() {
    $('#upload_file').unbind('submit').bind('submit', function() {
      e.preventDefault();
       var form = $(this);
         $.ajax({
          url : form.attr('action'), 
          type: form.attr('method'),
          data: form.serialize(),
          secureuri   :false,
          fileElementId :'userfile',
          dataType    : 'json',
          success : function (data, status)
          {
            if(data.status != 'error')
            {
              $('#files').html('<p>Reloading files...</p>');

            }
            alert(data.msg);
          }
        });
        return false;
      });
  });

</script>

Controller

public function docs() {
      $status = "";
      $msg = "";
      $file_element_name = 'userfile';


    if ($status != "error")
    {
        $config['upload_path'] = dirname($_SERVER["SCRIPT_FILENAME"])."/assets/img/posts";
        $config['upload_url']  = base_url()."/assets/img/posts";
        $config['allowed_types'] = 'gif|jpg|png|jpeg|pdf|doc|docx|docs|txt|xml';
        $config['max_height'] = 102048;
        $config['max_width']  = 102048;
        $config['max_size'] = 1024 * 8;
        $config['encrypt_name'] = TRUE;

        $this->load->library('upload', $config);

        if (!$this->upload->do_upload($file_element_name))
        {
            $status = 'error';
            $msg = $this->upload->display_errors('', '');
        }
        else
        {
            $data = $this->upload->data();
            $file_id = $this->Checkout_model->newcheckout($data['file_name']);
            if($file_id)
            {
                $status = "success";
                $msg = "File successfully uploaded";
            }
            else
            {
                unlink($data['full_path']);
                $status = "error";
                $msg = "Something went wrong when saving the file, please try again.";
            }
        }
        @unlink($_FILES[$file_element_name]);
      }
      echo json_encode(array('status' => $status, 'msg' => $msg));
    }

I just want to upload the file without refreshing the page. Currently, it's uploading the file but after upload its navigating to the controller address.

Answer 1

The reason why you're navigating to controller is because your call to preventDefault is from a non existent identifier e causing an error, you can remove it since you have return false later or just define the e .
Now when you're trying to upload a file with ajax you use a FormData object

$(function() {
  $('#upload_file').unbind('submit').bind('submit', function(e) {//<-- e defined here
    e.preventDefault();
    var form = $(this);
    var data = new FormData(this);
    $.ajax({
      url : form.attr('action'), 
      type: form.attr('method'),
      data: data,
      processData: false,
      contentType: false, 
      dataType    : 'json',
      success : function (data, status)
      {
        if(data.status != 'error')
        {
          $('#files').html('<p>Reloading files...</p>');

        }
        alert(data.msg);
      }
    });
    return false;
  });
});

Answer 2

Slightly different variation of solution that worked for me is given below:

<script type="text/javascript">
    $(function() {

        $('#upload_file').unbind('submit').bind('submit', function(e) {
            e.preventDefault();
            var file = document.getElementById('userfile').files[0];
            if(file==undefined){
                return false;
            }
            var formData = false;
            if (window.FormData) {
                formData = new FormData();
                formData.append("userfile", file);
            }
            var form = $(this);
            if(formData!==false){
                $.ajax({
                    url : form.attr('action'),
                    type: form.attr('method'),
                    data: formData,
                    processData: false,
                    secureuri: false,
                    contentType: false,
                    success : function (data, status)
                    {
                        if(data.status != 'error')
                        {
                            $('#files').html('<p>Reloading files...</p>');

                        }
                        alert(data.msg);
                    }
                });
            }
            return false;
        });
    });
</script>