app/Http/Controllers/LessonController.php

@@ -33,6 +33,7 @@ class LessonController extends Controller
         return view('grade-lesson.index', [
             'lessons' => $this->service->getAll($grade),
             'grade' => $grade,
+            'subjects' => $grade->subjects,
         ]);
     }
 

app/Models/Lesson.php

@@ -2,6 +2,7 @@
 
 namespace App\Models;
 
+use Illuminate\Contracts\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
@@ -40,4 +41,13 @@ class Lesson extends Model
     {
         return $this->belongsTo(Subject::class);
     }
+
+    public function scopeFilter(Builder $query): void
+    {
+        $subject_id = request('subject_id');
+
+        $query->when($subject_id, function (Builder $query, $subject_id) {
+            $query->where('subject_id', $subject_id);
+        });
+    }
 }

app/Services/LessonService.php

@@ -12,7 +12,7 @@ class LessonService implements ServiceInterface
 
     public function getAll(?Grade $grade = null): Collection
     {
-        return $grade->lessons;
+        return $grade->lessons()->filter()->get();
     }
 
     public function getGrades(): Collection

resources/views/grade-lesson/index.blade.php

@@ -1,4 +1,4 @@
-@extends('layouts.app')
+`@extends('layouts.app')
 
 @section('content')
     <div class="container col-md-5">
@@ -9,6 +9,27 @@
                     <a href="{{ route('grades.lessons.create', $grade) }}" class="btn btn-success">Добавить</a>
                 </div>
             </div>
+            <div class="card mt-4">
+                <div class="card-header">{{__('Фильтрация')}}</div>
+                <div class="card-body">
+                    <form action="{{ route('grades.lessons.index', $grade) }}" method="GET">
+                        <div class="mb-3">
+                            <label for="subject_id" class="form-label">Предмет:</label>
+                            <select id="subject_id" name="subject_id" class="form-select" required>
+                                <option value="">Выберите предмет</option>
+                                @foreach($subjects as $subject)
+                                    <option value="{{ $subject->id }}"> {{ $subject->id == request('subject_id') ? 'selected' : ''}}
+                                        {{ $subject->name }}
+                                    </option>
+                                @endforeach
+                            </select>
+                        </div>
+                        <div>
+                            <button type="submit" class="btn btn-primary">Фильтр</button>
+                        </div>
+                    </form>
+                </div>
+            </div>
             @if(count($lessons))
                 @foreach($lessons as $lesson)
                     <a href="{{ route('grades.lessons.show', [$grade, $lesson]) }}" class="text-decoration-none">
@@ -33,3 +54,4 @@
     </div>
 @endsection
 
+`