CakePHP Upload Plugin: Programmatic File Retrieval without a Form - cakephp

Question

I use CakePHP-Upload plugin, now need to use the upload without form, following this example: Programmatic File Retrieval without a Form
All my upload are stored in the associated model, called the Attachment.
So when I save the article, at the same time save the images in Attachmen model.
Plugin documentation suggests something like this:
<?php
$this->Article->set(array('file' => $image_path)); // ?????
$this->Article->save();
?>
I have a larger collection of images on the server, previously uploaded via the Joomla CMS, now I have a migration of data to a custom CMS built on CakePHP framework. I need to take all these pictures and upload again, through this plugin.
How to properly use this plugin for my needs, I try to put the path to a local picture, but uploading is not working ???
EDIT
$image_path = WWW_ROOT . 'img' . DS . 'attachment' . DS . '59'.DS.'hpim4799.jpg';
debug($image_path);
'C:\xampp\htdocs\portal\webroot\img\attachment\59\hpim4799.jpg'
Do not save the record and not create new images.
Note, uploading through HTML form works well, I use windows 7 and xampp server.
EDIT 2 / Solution
Image path must be valid url like 'http://localhost/portal/img/attachment/59/hpim4799.jpg'
$image_path = Router::url('/', true) . 'img/attachment/59/hpim4799.jpg';
Thank you.

Answer 1

Can you tell me what the content of the variable $image_url is? The doucmentation says you can add a file via the form, or you can do it programmatically. If you do that, use the $image_url as path to the image. If you got an associated model like Attachment you shoud use:
<?php
$this->Article->set(array('Attachment.file' => $image_path)); // path + file to file
$this->Article->save();
?>

Answer 2

After hours of searching for solutions and detailed inspection of the Behavior code I finally found it.
Because Behavior uses php FILTER_VALIDATE_URL Filter, path must be a valid URL. Here is an example:
<?php
$image_path = Router::url('/', true) . 'img/attachment/59/hpim4799.jpg';
// return http://localhost/portal/img/attachment/59/hpim4799.jpg
$this->Article->Attachment->set(array('file' => $image_path));
$this->Article->Attachment->save();
?>