improve DatabasePlanRepository documentation

docs/12-faq.md

@@ -29,9 +29,9 @@ If required for your billable model, modify the cashier migrations for UUIDs:
 ```php
 // Replace this:
 $table->unsignedInteger('owner_id');
-    
+
 // By this:
-$table->uuid('owner_id');  
+$table->uuid('owner_id');
 ```
 And in your `Billable` model add
 ```php
@@ -62,19 +62,17 @@ Firstly you create your own implementation of the plan repository and implement
 Implement the methods according to your needs and make sure you'll return a `Laravel\Cashier\Plan\Contracts\Plan`.
 
 ```php
-use App\Plan;
+use App\Models\Plan;
 use Laravel\Cashier\Exceptions\PlanNotFoundException;
+use Laravel\Cashier\Plan\Contracts\Plan as PlanContract;
 use Laravel\Cashier\Plan\Contracts\PlanRepository;
 
 class DatabasePlanRepository implements PlanRepository
 {
-    public static function find(string $name)
+    public static function find(string $name): PlanContract
     {
-        $plan = Plan::where('name', $name)->first();
-
-        if (is_null($plan)) {
-            return null;
-        }
+        /** @var Plan $plan */
+        $plan = Plan::where('name', $name)->firstOrFail();
 
         // Return a \Laravel\Cashier\Plan\Plan by creating one from the database values
         return $plan->buildCashierPlan();
@@ -83,7 +81,7 @@ class DatabasePlanRepository implements PlanRepository
         return $plan;
     }
 
-    public static function findOrFail(string $name)
+    public static function findOrFail(string $name): PlanContract
     {
         if (($result = self::find($name)) === null) {
             throw new PlanNotFoundException;
@@ -95,15 +93,20 @@ class DatabasePlanRepository implements PlanRepository
 ```
 ::: details Example Plan model (app/Plan.php) with buildCashierPlan and returns a \Laravel\Cashier\Plan\Plan
 ```php
-<?php
-
-namespace App;
+namespace App\Models;
 
-use Laravel\Cashier\Plan\Plan as CashierPlan;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
+use Laravel\Cashier\Cashier;
+use Laravel\Cashier\Plan\Plan as CashierPlan;
+use Money\Currency;
+use Money\Money;
+use Laravel\Cashier\Order\OrderItemPreprocessorCollection as Preprocessors;
 
 class Plan extends Model
 {
+    use HasFactory;
+
     /**
      * Builds a Cashier plan from the current model.
      *
@@ -112,25 +115,64 @@ class Plan extends Model
     public function buildCashierPlan(): CashierPlan
     {
         $plan = new CashierPlan($this->name);
-        
-        return $plan->setAmount(mollie_array_to_money($this->amount))
+
+        return $plan->setAmount($this->getAmount())
             ->setInterval($this->interval)
             ->setDescription($this->description)
-            ->setFirstPaymentMethod($this->first_payment_method)
-            ->setFirstPaymentAmount(mollie_array_to_money($this->first_payment_amount))
-            ->setFirstPaymentDescription($this->first_payment_description)
-            ->setFirstPaymentRedirectUrl($this->first_payment_redirect_url)
-            ->setFirstPaymentWebhookUrl($this->first_payment_webhook_url)
-            ->setOrderItemPreprocessors(Preprocessors::fromArray($this->order_item_preprocessors));
+            ->setFirstPaymentMethod(config('cashier.first_payment.method'))
+            ->setFirstPaymentAmount($this->getAmount())
+            ->setFirstPaymentDescription($this->description)
+            ->setFirstPaymentRedirectUrl(route('plans-payment.success', ['plan' => $this->id]))
+            ->setFirstPaymentWebhookUrl(Cashier::firstPaymentWebhookUrl())
+            ->setOrderItemPreprocessors(Preprocessors::fromArray(config('cashier_plans.defaults.order_item_preprocessors')));
+    }
+
+    private function getAmount(): Money
+    {
+        return new Money($this->price, new Currency($this->currency));
     }
 }
 ```
 
-Note: In this case you'll need to add accessors for all the values (like amount, interval, fist_payment_method etc.)
-to make sure you'll use the values from your defaults (config/cashier_plans.php > defaults).
+The DB-schema for the above Model could look like the following.
+
+```php
+Schema::create('plans', function (Blueprint $table) {
+	$table->id();
+	$table->string('name');
+	$table->string('description');
+	$table->string('price');
+	$table->string('currency');
+	$table->string('interval');
+	$table->timestamps();
+});
+```
+
+You can also create a `PlanFactory`.
+
+```php
+class PlanFactory extends Factory
+{
+    /**
+     * Define the model's default state.
+     *
+     * @return array<string, mixed>
+     */
+    public function definition(): array
+    {
+        return [
+            'name' => $this->faker->name,
+            'description' => $this->faker->sentence,
+            'price' => '10.00',
+            'currency' => $this->faker->currencyCode,
+            'interval' => $this->faker->randomElement(['month', 'year']),
+        ];
+    }
+}
+```
 :::
 
-Then you just have to bind your implementation to the Laravel/Illuminate container by registering the binding in a service provider
+Then you have to bind your implementation to the Laravel/Illuminate container by registering the binding in a service provider
 
 ```php
 class AppServiceProvider extends ServiceProvider
@@ -142,5 +184,16 @@ class AppServiceProvider extends ServiceProvider
 }
 ```
 
+In order to test if your implementation is setup correctly, you can run the following code snippet.
+```php
+use Laravel\Cashier\Plan\Contracts\PlanRepository;
+use App\Models\Plan;
+
+Plan::factory()->create(["name" => "test"]);
+resolve(PlanRepository::class)->find("test");
+```
+
+---
+
 Cashier Mollie will now use your implementation of the PlanRepository. For coupons this is basically the same,
-just make sure you implement the CouponRepository contract and bind the contract to your own implementation.
+make sure you implement the CouponRepository contract and bind the contract to your own implementation.