beforeSave method not working in cakephp3 - cakephp

Question

I have data that I want to modify first before saving it to my database, and so I've researched the beforeSave method.
I have a user's picture input and I want to save its path on my DB after successfully validating it and here's my current code:
src/model/table/UsersTable.php
use Cake\ORM\Entity;
use Cake\Event\Event;
use ArrayObject;
use Cake\Validation\Validator;
public function validationDefault(Validator $validator)
{
$validator
->allowEmptyFile('image_location')
->add('image_location',
[
'mimeType' => [
'rule' => array('mimeType', array( 'image/png', 'image/jpg', 'image/jpeg')),
'message' => 'Please upload images only (png, jpg).'
],
'fileSize' => [
'rule' => array('fileSize', '<=', '10MB'),
'message' => 'Image must be less than 10MB.'
],
]);
return $validator;
}
public function beforeSave($event, $entity, $options)
{
if ($entity->image_location['name']) {
$tmp = $entity->image_location['tmp_name'];
$hash = rand();
$date = data("Ymd");
$image = $dage.$hash;
$target = WWW_ROOT.'img'.DS.'uploads'.DS;
$target = $target.basename($image);
$image_location = "uploads/".$image;
$entity->image_location = $image_location;
move_uploaded_file($tmp, $target);
}
}
The only working part on this is the validation part, but after it successfully validates the image file, the beforeSave method is not working.
What error do I have in my current code or how can I use the beforeSave method in cakephp3.
Thank you very much!
EDIT
I even tried this line:
public function beforeSave($event, $entity, $options)
{
debug($entity);
if ($entity->image_location['name']) {
$tmp = $entity->image_location['tmp_name'];
$hash = rand();
$date = data("Ymd");
$image = $dage.$hash;
$target = WWW_ROOT.'img'.DS.'uploads'.DS;
$target = $target.basename($image);
$image_location = "uploads/".$image;
$entity->image_location = $image_location;
move_uploaded_file($tmp, $target);
}
}
to check the entity the beforeSave method is receiving but, it does not output anything.