Implement Expense Approval Workflow with Notifications

app/Filament/Resources/ExpenseResource.php

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+
+
+<?php
+
+namespace App\Filament\Resources;
+
+use App\Filament\Resources\ExpenseResource\Pages;
+use App\Models\Expense;
+use Filament\Forms;
+use Filament\Resources\Resource;
+use Filament\Tables;
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Model;
+
+class ExpenseResource extends Resource
+{
+    protected static ?string $model = Expense::class;
+
+    protected static ?string $navigationIcon = 'heroicon-o-currency-dollar';
+    protected static ?string $navigationGroup = 'Finance';
+
+    public static function form(Forms\Form $form): Forms\Form
+    {
+        return $form
+            ->schema([
+                Forms\Components\TextInput::make('amount')
+                    ->required()
+                    ->numeric()
+                    ->prefix('$')
+                    ->minValue(0.01)
+                    ->step(0.01),
+                Forms\Components\TextInput::make('description')
+                    ->required()
+                    ->maxLength(255),
+                Forms\Components\DatePicker::make('date')
+                    ->required()
+                    ->maxDate(now()),
+                Forms\Components\Select::make('approval_status')
+                    ->options([
+                        'pending' => 'Pending',
+                        'approved' => 'Approved',
+                        'rejected' => 'Rejected',
+                    ])
+                    ->disabled()
+                    ->dehydrated(false),
+                Forms\Components\Textarea::make('rejection_reason')
+                    ->visible(fn (?Model $record) => $record?->approval_status === 'rejected')
+                    ->maxLength(1000)
+                    ->columnSpanFull(),
+            ]);
+    }
+
+    public static function table(Tables\Table $table): Tables\Table
+    {
+        return $table
+            ->columns([
+                Tables\Columns\TextColumn::make('amount')
+                    ->money('USD')
+                    ->sortable(),
+                Tables\Columns\TextColumn::make('description')
+                    ->searchable(),
+                Tables\Columns\TextColumn::make('date')
+                    ->date()
+                    ->sortable(),
+                Tables\Columns\TextColumn::make('user.name')
+                    ->label('Submitted By')
+                    ->searchable(),
+                Tables\Columns\TextColumn::make('approval_status')
+                    ->badge()
+                    ->color(fn (string $state): string => match ($state) {
+                        'approved' => 'success',
+                        'rejected' => 'danger',
+                        default => 'warning',
+                    }),
+                Tables\Columns\TextColumn::make('approver.name')
+                    ->label('Approved By')
+                    ->visible(fn (Model $record): bool => $record->approved_by !== null),
+            ])
+            ->filters([
+                Tables\Filters\SelectFilter::make('approval_status')
+                    ->options([
+                        'pending' => 'Pending',
+                        'approved' => 'Approved',
+                        'rejected' => 'Rejected',
+                    ]),
+            ])
+            ->actions([
+                Tables\Actions\ViewAction::make(),
+                Tables\Actions\Action::make('approve')
+                    ->action(fn (Expense $record) => $record->approve())
+                    ->requiresConfirmation()
+                    ->visible(fn (Expense $record) => $record->isPending())
+                    ->color('success')
+                    ->icon('heroicon-o-check'),
+                Tables\Actions\Action::make('reject')
+                    ->form([
+                        Forms\Components\Textarea::make('reason')
+                            ->required()
+                            ->maxLength(1000)
+                            ->label('Rejection Reason'),
+                    ])
+                    ->action(fn (Expense $record, array $data) => $record->reject($data['reason']))
+                    ->visible(fn (Expense $record) => $record->isPending())
+                    ->color('danger')
+                    ->icon('heroicon-o-x-mark'),
+            ])
+            ->defaultSort('created_at', 'desc');
+    }
+
+    public static function getRelations(): array
+    {
+        return [];
+    }
+
+    public static function getPages(): array
+    {
+        return [
+            'index' => Pages\ListExpenses::route('/'),
+            'create' => Pages\CreateExpense::route('/create'),
+            'edit' => Pages\EditExpense::route('/{record}/edit'),
+        ];
+    }
+
+    public static function getNavigationBadge(): ?string
+    {
+        return static::getModel()::where('approval_status', 'pending')->count() ?: null;
+    }
+}

app/Models/Expense.php

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+
+
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Support\Facades\Auth;
+use App\Notifications\ExpenseApprovalNotification;
+
+class Expense extends Model
+{
+    protected $fillable = [
+        'amount',
+        'description',
+        'date',
+        'approval_status',
+        'rejection_reason',
+        'approved_by',
+        'approved_at'
+    ];
+
+    protected $casts = [
+        'date' => 'date',
+        'approved_at' => 'datetime',
+        'amount' => 'decimal:2'
+    ];
+
+    public function user(): BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    public function approver(): BelongsTo
+    {
+        return $this->belongsTo(User::class, 'approved_by');
+    }
+
+    public function approve()
+    {
+        $this->update([
+            'approval_status' => 'approved',
+            'approved_by' => Auth::id(),
+            'approved_at' => now(),
+        ]);
+
+        $this->user->notify(new ExpenseApprovalNotification($this, 'approved'));
+    }
+
+    public function reject($reason)
+    {
+        $this->update([
+            'approval_status' => 'rejected',
+            'rejection_reason' => $reason,
+            'approved_by' => Auth::id(),
+            'approved_at' => now(),
+        ]);
+
+        $this->user->notify(new ExpenseApprovalNotification($this, 'rejected'));
+    }
+
+    public function isPending(): bool
+    {
+        return $this->approval_status === 'pending';
+    }
+}

app/Notifications/ExpenseApprovalNotification.php

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+
+
+<?php
+
+namespace App\Notifications;
+
+use App\Models\Expense;
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Notifications\Notification;
+use Illuminate\Notifications\Messages\MailMessage;
+
+class ExpenseApprovalNotification extends Notification implements ShouldQueue
+{
+    use Queueable;
+
+    public function __construct(
+        protected Expense $expense,
+        protected string $status
+    ) {}
+
+    public function via($notifiable): array
+    {
+        return ['mail', 'database'];
+    }
+
+    public function toMail($notifiable): MailMessage
+    {
+        $message = $this->status === 'approved' 
+            ? 'Your expense has been approved.'
+            : 'Your expense has been rejected.';
+
+        return (new MailMessage)
+            ->subject("Expense {$this->status}")
+            ->greeting("Hello {$notifiable->name}")
+            ->line($message)
+            ->line("Amount: {$this->expense->amount}")
+            ->line("Description: {$this->expense->description}")
+            ->when($this->status === 'rejected', function($mail) {
+                return $mail->line("Reason: {$this->expense->rejection_reason}");
+            })
+            ->line("Date: {$this->expense->date->format('Y-m-d')}");
+    }
+
+    public function toArray($notifiable): array
+    {
+        return [
+            'expense_id' => $this->expense->id,
+            'status' => $this->status,
+            'amount' => $this->expense->amount,
+            'reason' => $this->expense->rejection_reason,
+            'approved_by' => $this->expense->approved_by,
+            'approved_at' => $this->expense->approved_at,
+        ];
+    }
+}

database/migrations/2024_01_10_000000_add_approval_fields_to_expenses_table.php

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+
+
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up()
+    {
+        Schema::table('expenses', function (Blueprint $table) {
+            $table->enum('approval_status', ['pending', 'approved', 'rejected'])->default('pending');
+            $table->text('rejection_reason')->nullable();
+            $table->foreignId('approved_by')->nullable()->constrained('users');
+            $table->timestamp('approved_at')->nullable();
+        });
+    }
+
+    public function down()
+    {
+        Schema::table('expenses', function (Blueprint $table) {
+            $table->dropColumn(['approval_status', 'rejection_reason', 'approved_by', 'approved_at']);
+        });
+    }
+};