categories for invoices/bills

app/Models/Expense/Bill.php

@@ -60,6 +60,11 @@ class Bill extends Model
      */
     protected $cloneable_relations = ['items', 'totals'];
 
+    public function category()
+    {
+        return $this->belongsTo('App\Models\Setting\Category');
+    }
+
     public function vendor()
     {
         return $this->belongsTo('App\Models\Expense\Vendor');

app/Models/Income/Invoice.php

@@ -61,6 +61,11 @@ class Invoice extends Model
      */
     protected $cloneable_relations = ['items', 'totals'];
 
+    public function category()
+    {
+        return $this->belongsTo('App\Models\Setting\Category');
+    }
+
     public function customer()
     {
         return $this->belongsTo('App\Models\Income\Customer');

app/Models/Setting/Category.php

@@ -22,9 +22,19 @@ class Category extends Model
      */
     public $sortable = ['name', 'type', 'enabled'];
 
-    public function revenues()
+    public function bills()
     {
-        return $this->hasMany('App\Models\Income\Revenue');
+        return $this->hasMany('App\Models\Expense\Bill');
+    }
+
+    public function invoices()
+    {
+        return $this->hasMany('App\Models\Income\Invoice');
+    }
+
+    public function items()
+    {
+        return $this->hasMany('App\Models\Item\Item');
     }
 
     public function payments()
@@ -32,9 +42,9 @@ class Category extends Model
         return $this->hasMany('App\Models\Expense\Payment');
     }
 
-    public function items()
+    public function revenues()
     {
-        return $this->hasMany('App\Models\Item\Item');
+        return $this->hasMany('App\Models\Income\Revenue');
     }
 
     /**