Learning WardrobeCMS source code, how do they retrieve posts without db request? - laravel

Question

Newbie here. I'm learning Laravel and WardrobeCMS is a good one to study IMO. Just wondering if you guys could point me how they retrieve posts with requesting db?
In homepage, the HomeController has this line.
$posts = $this->posts->active(Config::get('core::wardrobe.per_page'));
In WardrobeServiceProvider, they bind PostRepoitory with DbPostRepository and here is their 'active' method.
public function active($per_page)
{
$per_page = is_numeric($per_page) ? $per_page : 5;
\Debugbar::info('calling posts active method');
return Post::with(array('tags', 'user'))
->where('active', 1)
->where('publish_date', '<=', new DateTime)
->orderBy('publish_date', 'desc')
->paginate($per_page);
}
The return statement looks like the Eloquent command but I don't see any db request in Debugbar console. How does this work? Please advise.
I am a designer trying to learn coding and Laravel 'illuminates' me. In my current dev project, I have around 4-10 db calls in each page. My goal here is to reduce db calls as much as possible and I think WardrobeCMS source code is my starting point.

Answer 1

Post::with()->where()->paginate(); doesn't always 'call' database?
In short: Yes it does!
Post is an Eloquent ORM because, basically every model (i.e. Post) in Laravel extends the Eloquent/Model class and this Eloquent/Model class uses Query Builder (DB in your case) class along with other classes to query the database and in your example, the Post is something like this:
class Post extends Eloquent {
// ...
}
SInce the Post class extends the Eloquent class so Post have access (inherited from Eloquent) to all (protected and public only) methods of Eloquent class, so, if the Eloquent has a function/method like this (actually has):
public function with($relation)
{
//...
}
Then the Post class can call that function/method like this:
Post::with()
So, actually Post::with()->where()->paginate() call interact with database in this case but it's not necessary that every database interaction has to be using DB::table(), instead, it's a convenient way to query the database using an ORM and don't forget that, the ORM is just a wrapper over the query builder, behind the scene, the Post Eloquent Model is using the query builder.
You should the manual instead of reading the source code of another application, once you get the basic idea then you may read source code of other Laravel applications to get some ideas that other developers uses.
Update: If you are not seeing any queries in the debugger then the application is using the caching feature of Laravel to cache database queries for a certain period of time so it can use those later without interacting with the database to speed up the process.