BF self to static, which allows extendable models

src/Models/Product.php

@@ -134,12 +134,12 @@ class Product extends Model implements Purchasable, Cartable
 
     public function parent()
     {
-        return $this->belongsTo(self::class, 'parent_id');
+        return $this->belongsTo(static::class, 'parent_id');
     }
 
     public function children(): HasMany
     {
-        return $this->hasMany(self::class, 'parent_id');
+        return $this->hasMany(static::class, 'parent_id');
     }
 
     public function attributes(): HasMany

src/Models/ProductCategory.php

@@ -76,19 +76,19 @@ class ProductCategory extends Model
 
     public function parent(): BelongsTo
     {
-        return $this->belongsTo(self::class, 'parent_id');
+        return $this->belongsTo(static::class, 'parent_id');
     }
 
     public function children(): HasMany
     {
-        return $this->hasMany(self::class, 'parent_id')
+        return $this->hasMany(static::class, 'parent_id')
             ->where('is_visible', true)
             ->orderBy('sort_order');
     }
 
     public function allChildren(): HasMany
     {
-        return $this->hasMany(self::class, 'parent_id')
+        return $this->hasMany(static::class, 'parent_id')
             ->orderBy('sort_order');
     }
 

src/Traits/HasProductRelations.php

@@ -10,7 +10,7 @@ trait HasProductRelations
     public function productRelations(): BelongsToMany
     {
         return $this->belongsToMany(
-            self::class,
+            static::class,
             config('shop.tables.product_relations', 'product_relations'),
             'product_id',
             'related_product_id'

workbench/app/Models/Product.php

@@ -0,0 +1,5 @@
+<?php
+
+namespace App\Models;
+
+class Product extends \Blax\Shop\Models\Product {}