How to correctly pass a file to a controller in OpenCart 2.3?

Question

opencart

Good afternoon, I can’t transfer the file through the form and FormData
Now the code is in its current state:

<form id="selection-form" method="post" name="fileinfo">
  <input type="file" name="file" value="" /> 
  <input type="number" name="selection_mu">
  <input type="number" name="selection_dp">
  <input type="number" name="selection_bs">
  <input type="number" name="selection_dk">
  <input type="text" id="phone" name="selection_phone">
  <input type="submit"  id="selection-send" value="Отправить специалисту">
</form>

var form = document.forms.namedItem("fileinfo");
form.addEventListener('submit', function(ev) {

  var oOutput = document.querySelector("div"),
    oData = new FormData(form);

  oData.append("CustomField", "This is some extra data");

  var oReq = new XMLHttpRequest();
  
  oReq.open("POST", "index.php?route=information/information/send", true);
  oReq.onload = function(oEvent) {
  
    if (oReq.status == 200) {
      console.log('Uploaded!');
      console.log(oReq.response);
            console.log(oReq.responseText);
    } else {
      console.log("Error " + oReq.status + " occurred when trying to upload your file.<br \/>");
    }
  };

  oReq.send(oData);
  ev.preventDefault();
}, false);

controller

public function send() {
    
    $json = array();
    
    if ($this->request->server['REQUEST_METHOD'] == 'POST') {
      
      $message = '';
      
      if (isset($this->request->post['selection_mu'])) {
        $message .= $this->request->post['selection_mu'].'<br>';
      }
      
      if (isset($this->request->post['selection_dp'])) {
        $message .= $this->request->post['selection_dp'].'<br>';
      }
      
      if (isset($this->request->post['selection_bs'])) {
        $message .= $this->request->post['selection_bs'].'<br>';
      }
      
      if (isset($this->request->post['selection_dk'])){
        $message .= $this->request->post['selection_dk'].'<br>';
      }
      
      if (isset($this->request->post['selection_phone'])) {
        $message .= $this->request->post['selection_phone'].'</b><br>';
      }
      
      $mail = new Mail();
      $mail->protocol = $this->config->get('config_mail_protocol');
      $mail->parameter = $this->config->get('config_mail_parameter');
      $mail->smtp_hostname = $this->config->get('config_mail_smtp_hostname');
      $mail->smtp_username = $this->config->get('config_mail_smtp_username');
      $mail->smtp_password = html_entity_decode($this->config->get('config_mail_smtp_password'), ENT_QUOTES, 'UTF-8');
      $mail->smtp_port = $this->config->get('config_mail_smtp_port');
      $mail->smtp_timeout = $this->config->get('config_mail_smtp_timeout');

      $mail->setTo('[email protected]');
      $mail->setFrom('[email protected]');
      $mail->setSender(html_entity_decode('Подбор замка по фото', ENT_QUOTES, 'UTF-8'));
      $mail->setSubject('Сообщение');
      $mail->setText($message);
      
      // Подгружаем файлы
      if (isset($this->request->post['file'])){
                $mail->addAttachment(DIR_UPLOAD.$this->request->post['file']);
        $json['file'] = $this->request->post['file'];
            }
      
      $mail->send();
      $json['success'] = $this->request->post['file'];
      
      $this->response->addHeader('Content-Type: application/json');
      $this->response->setOutput(json_encode($json));
    }
  }

If you start debugging, then $this->request->post['file'] undefined

Answer 1

In the source code, everything was implemented a long time ago

$('button[id^=\'button-upload\']').on('click', function() {
  var node = this;

  $('#form-upload').remove();

  $('body').prepend('<form enctype="multipart/form-data" id="form-upload" style="display: none;"><input type="file" name="file" /></form>');

  $('#form-upload input[name=\'file\']').trigger('click');

  if (typeof timer != 'undefined') {
    	clearInterval(timer);
  }

  timer = setInterval(function() {
    if ($('#form-upload input[name=\'file\']').val() != '') {
      clearInterval(timer);

      $.ajax({
        url: 'index.php?route=tool/upload',
        type: 'post',
        dataType: 'json',
        data: new FormData($('#form-upload')[0]),
        cache: false,
        contentType: false,
        processData: false,
        beforeSend: function() {
          $(node).button('loading');
        },
        complete: function() {
          $(node).button('reset');
        },
        success: function(json) {
          $('.text-danger').remove();

          if (json['error']) {
            $(node).parent().find('input').after('<div class="text-danger">' + json['error'] + '</div>');
          }

          if (json['success']) {
            alert(json['success']);

            $(node).parent().find('input').val(json['code']);
          }
        },
        error: function(xhr, ajaxOptions, thrownError) {
          alert(thrownError + "\r\n" + xhr.statusText + "\r\n" + xhr.responseText);
        }
      });
    }
  }, 500);
});