MicroFrameWork/app/services/PostService.php

<?php

namespace app\services;

use app\models\Post;
use kernel\FormModel;

class PostService
{
    public function create(FormModel $form_model): false|Post
    {
        $model = new Post();
        $model->content = $form_model->getItem('content');
        $model->user_id = $form_model->getItem('user_id');
        if ($model->save()){
            return $model;
        }

        return false;
    }

    public function update(FormModel $form_model, Post $post): false|Post
    {
        $post->content = $form_model->getItem('content');
        $post->user_id = $form_model->getItem('user_id');
        if ($post->save()){
            return $post;
        }

        return false;
    }
}