What is service container, Service Provider, AppServiceProvider in laravel

service provider:
> A service that is provided to laravel ie Cache Service, Mail Service . They tell Laravel how to boot (initialize) services, bind things into the service container, register events, macros, etc.
Service container (its manage class dependencies)
    A container that make objects of service provider so we can use it in whole application

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AppServiceProvider: app/Providers/AppServiceProvider.php
It’s automatically loaded because it’s registered in config/app.php under providers.

It has two methods, register() For binding services, boot() → For initialization after services are registered

1. FORCE HTTPS
   
   

   if ($this->app->environment('production')) {
           URL::forceScheme('https');
   }

    
2. Custom Blade Directives
   

   use Illuminate\Support\Facades\Blade;
   public function boot(): void
   {
       Blade::directive('currency', function ($amount) {
           return "<?php echo '$' . number_format($amount, 2); ?>";
       });
   }
   
   @currency(1500)  <!-- outputs $1,500.00 -->
   

3. Cutom validation rule
   

   use Illuminate\Support\Facades\Validator;
   public function boot(): void
   {
       Validator::extend('even', function ($attribute, $value, $parameters, $validator) {
           return $value % 2 === 0;
       });
   }
   ####
   $request->validate([
       'number' => 'required|even'
   ]);
   

4. Share data with views
   

   // Share the `today_count` variable globally across all views
   // use any viewname in place of * to share only with that ie index
   \Illuminate\Support\Facades\View::composer('*', function ($view) { 
       $todo_list = \App\Models\Todo::where("is_completed","0");
   
       if (\Illuminate\Support\Facades\Auth::check()) {
               $todo_list = $todo_list->where("user_id", $user_id);
       }
       $today_count = $todo_list->count();
       $view->with('today_count', $today_count);
   });