Select posts based on selected categories - php

Question

I have following scenario:
user selects couple categories
user should see posts which belongs to these categories
post belong to one or more categories
I setup the database like this:
users -> category_user <- categories
posts -> categoriy_post <- categories
I managed to accomplish this, but I had to find all ids from these tables to find relevant posts. I need to make it simpler because this approach is blocking some other actions I need to do. This is my code:
$categoryIds = Auth::user()->categories;
$ids = array();
$t = array_filter((array)$categoryIds);
if(!empty($t)){
foreach ($categoryIds as $key => $value) {
$ids[] = $value->id;
}
}else{
return View::make("main")
->with("posts", null)
->with("message", trans("front.noposts"))->with("option", "Latest");
}
$t = array_filter((array)$ids);
if(!empty($t)){
$p = DB::table("category_post")->whereIn("category_id", $ids)->get();
}else{
return View::make("main")
->with("posts", null)
->with("message", trans("front.noposts"))->with("option", "Latest");
}
$postsIds = array();
foreach ($p as $key => $value) {
$postsIds[] = $value->post_id;
}
$t = array_filter((array)$postsIds);
if(!empty($t)){
$postIds = array_unique($postsIds);
$posts = Post::whereIn("id", $postsIds)
->where("published", "=", "1")
->where("approved", "=", "1")
->where("user_id", "!=", Auth::user()->id)
->orderBy("created_at", "desc")
->take(Config::get("settings.num_posts_per_page"))
->get();
return View::make("main")
->with("posts", $posts)->with("option", "Latest");
}else{
return View::make("main")
->with("posts", null)
->with("message", trans("front.noposts"))->with("option", "Latest");
}
How to do this properly without this bunch code?

Answer 1

Yes, there is Eloquent way:
$userCategories = Auth::user()->categories()
->select('categories.id as id') // required to use lists on belongsToMany
->lists('id');
if (empty($userCategories)) // no categories, do what you need
$posts = Post::whereHas('categories', function ($q) use ($userCategories) {
$q->whereIn('categories.id', $userCategories);
})->
... // your constraints here
->get();
if (empty($posts)) {} // no posts
return View::make() ... // with posts
Or even better with this clever trick:
$posts = null;
Auth::user()->load(['categories.posts' => function ($q) use (&$posts) {
$posts = $q->get();
}]);
if (empty($posts)) // no posts
return View... // with posts
Obviously, you can write joins, or even raw sql ;)

Answer 2

You can take those categories directly from the database from user records:
SELECT ...
FROM posts AS p
INNER JOIN category_post AS cp ON cp.id_post = p.id
INNER JOIN categories AS c on c.id = cp.id_category
INNER JOIN category_user AS cu ON cu.id_category = c.id
WHERE cu.id_user = 123 AND p.published = 1 AND ...
Joins in Laravel can be achieved, see the documentation: laravel.com/docs/queries#joins Maybe there is also an Eloquent way, I don't know, try searching :-)