how to use cache in cakePHP3 - caching

Question

I am trying to use cache in cakePHP3 to store query results.
I declared a cache adapter named "bl"
config/app.php :
/**
* Configure the cache adapters.
*/
'Cache' => [
'default' => [
'className' => 'File',
'path' => CACHE,
'url' => env('CACHE_DEFAULT_URL', null),
],
'bl' => [
'className' => 'File',
'path' => CACHE . 'bl/',
'url' => env('CACHE_DEFAULT_URL', null),
'duration' => '+1 week',
],
src/Controller/UsersController.php :
use Cake\Cache\Cache;
...
public function test()
{
$this->autoRender = false;
$this->loadModel('Users');
$Users = $this->Users->find('all');
$Users->cache('test', 'bl');
debug(Cache::read('test', 'bl'));
}
The debug return "false".
tmp/cache/bl/ directory were well created, but no cache files were generated.
Am I missing something ?

Answer 1

Your query is never being executed, hence it's never going to be cached. Run the query by invoking all(), or toArray(), or by iterating over it, etc...
See also
Cookbook > Database Access & ORM > Query Builder > How Are Queries Lazily Evaluated

Answer 2

You are not calling the proper method, you need to use Cache::write() not Users->cache(). I updated your code below:
use Cake\Cache\Cache;
...
public function test()
{
$this->autoRender = false;
$this->loadModel('Users');
$Users = $this->Users->find('all');
Cache::write('cache_key_name', $Users, 'bl');
debug(Cache::read('cache_key_name', 'bl'));
}
See https://book.cakephp.org/3.0/en/core-libraries/caching.html#writing-to-a-cache

Answer 3

I was able to find the solution with your 2 answers, the final code is :
public function test()
{
$this->autoRender = false;
$users = $this->Users->find('all')->toArray();
Cache::write('test_cache', $users, 'bl');
debug(Cache::read('test_cache', 'bl'));
}