How to list related blog posts in OctoberCMS - laravel

Question

I am building an App with OctoberCMS and wanted to list related blog posts at the bottom of each post page basing on categories. I figured out rainlab_blog_posts table does not have a foreign key pointing to blog categories table. To achieve what wanted I thought of extending the blog_posts table and added category_id as foreign key using a plugin. I defined foreign key constraints in table migration. Everthing seem to be fine. My challenge is, How can I insert category id in posts table each time a new post is created. OctoberCMS create post backend has an option where the author assigns a category to a new blog post by selecting from list. Just don't understand how to pass this category id and insert into rainlab_blog_posts table in category_id field.
This is what I want to achieve in my API:
routes.php
use Rainlab\Blog\Models\Post;
Route::get('apiv1/related-posts/{postid}',function($id)
{
$post = Post::where('id',$id)->first();
$posts = Post::where('category_id',$post->category_id)
->where('id','!=',$id)
->orderBy('views','desc')
->get()->take(5);
return $posts;
});
Or if there is a better way of achieving this will appreciate. Cheers!

Answer 1

Hmm seems something wrong here,
As first I can see from Blog Plugin that Blog <=> Category it is MM relation so you will not find category_id in rainlab_blog_posts table as all relation is maintained by this mm-relation table rainlab_blog_posts_categories.
So I think you will select only one category for blog so you can get related blogs for only that category. [ assuming from your code and description ]
we can utilize relationships for that.
So your code can look like this
use Rainlab\Blog\Models\Post;
Route::get('apiv1/related-posts/{postid}', function($id)
{
$post = Post::where('id',$id)->first();
// we need this because there will be mm relation so
// we fetch first category and this will be based on
// [ name sorting - does not matter as there will be only one cat. ]
$firstCategory = $post->categories()->first();
// now we fetch only that post which are related to that category
// but we skip current post and sort them and pick 5 posts
$posts = $firstCategory->posts()
->where('id', '!=', $id)
->orderBy('views','desc')
->limit(5) // use limit instead of take()
->get();
// use limit instead of take() as we don't need extra data so
// just put limit in sql rather fetching it from db then
// putting limit by code - limit() is more optimised way
return $posts;
});
Good thing now you don't need to add that category_id field on rainlab_blog_posts. So, I guess now you Also don't need to worry about adding it during post insertion.
if any doubts please comment.

Answer 2

Incase you simply want to display related blog posts without having to customize the blog database, there is an OctoberCMS plugin called Related Articles
that requires rainlab blog plugin. It will display all the other articles belonging to the post's category.
On your Backend menu, go to settings,on System, go to Updates and Plugins.
Go to Install plugins. Search for plugin Related articles. The creator is Tallpro. Install it.
Go to CMS. On the page you want related articles, go to components and drag Related articles. Save and preview it. You can also fork the component to edit how you want your related articles to be displayed. You will find more information on the documentation.
If you encounter any problems feel free to inquire or you can check out the plugin reviews for problems faced and their solution.