save image with cakephp3 - image

Question

I want to save the image path through a form, but the path of the image is not saved.
i've tried with this but i don't know where to put the code
MultimediaController:
public function add()
{
$multimedia = $this->Multimedia->newEntity();
if ($this->request->is('post')) {
$multimedia = $this->Multimedia->patchEntity($multimedia, $this->request->data);
$file = $_FILES['url'];
$path = 'files/' .$_FILES['url']['name'];
move_uploaded_file($this->data['url']['tmp_name'], $path);
if ($this->Multimedia->save($multimedia)) {
$this->Flash->success('The multimedia has been saved.');
return $this->redirect(['action' => 'index']);
} else {
$this->Flash->error('The multimedia could not be saved. Please, try again.');
}
}
$categories = $this->Multimedia->Categories->find('list', ['limit' => 200]);
$this->set(compact('multimedia', 'categories'));
$this->set('_serialize', ['multimedia']);
}
add.ctp
<?= $this->Form->create($multimedia, array('enctype' => 'multipart/form-data')); ?>
<fieldset>
<legend><?= __('Add Multimedia') ?></legend>
<?php
echo $this->Form->input('title');
echo $this->Form->input('description');
echo $this->Form->input('mime_type');
echo $this->Form->input('filename');
echo $this->Form->input('url', array('type' => 'file'));
echo $this->Form->input('category_id', ['options' => $categories]);
echo $this->Form->input('created_by');
?>
</fieldset>
<?= $this->Form->button(__('Submit')) ?>
<?= $this->Form->end() ?>
I'm new to cakephp 3 and am a bit lost. Please help.
Update:
already achieved to save the image:
$file = $_FILES['url'];
$path = "webroot\\files\\" .$_FILES['url']['name'];
print_r($file);
move_uploaded_file($_FILES['url']['tmp_name'], $path);
if ($this->Multimedia->save($multimedia)) {
$this->Flash->success('The multimedia has been saved.');
return $this->redirect(['action' => 'index']);
} else {
$this->Flash->error('The multimedia could not be saved. Please, try again.');
}
But now the "url" is not saved in the database

Answer 1

I hope this help you, the script here has some improvements like using the short deceleration for arrays:
The Controller code:
//don't forget to import the Folder class
use Cake\Filesystem\Folder;
public function add()
{
$multimedia = $this->Multimedia->newEntity();
if ($this->request->is('post')) {
$multimedia = $this->Multimedia->patchEntity($multimedia, $this->request->data);
//upload script start here
$mm_dir = new Folder(WWW_ROOT . 'upload_dir', true, 0755);
$target_path = $mm_dir->pwd() . DS . $this->request->data('url.name');
move_uploaded_file($this->request->data('url.tmp_name'), $target_path);
//save the file name in the field 'url'
$multimedia->url= $this->request->data('url.name');
//the script ends here
if ($this->Multimedia->save($multimedia)) {
// ............
} else {
// .........
}
}
// ..........
}
add.ctp // improvement
<?= $this->Form->create($multimedia, ['type' => 'file']); ?>
echo $this->Form->input('url', ['type' => 'file']);