Validate when editing the quantity of a component that the new quantity is > the amount checked out

app/Http/Controllers/Components/ComponentsController.php

@@ -8,6 +8,7 @@ use App\Models\Component;
 use Illuminate\Support\Facades\Auth;
 use Illuminate\Support\Facades\Input;
 use Illuminate\Support\Facades\Storage;
+use Illuminate\Support\Facades\Validator;
 
 /**
  * This class controls all actions related to Components for
@@ -121,6 +122,16 @@ class ComponentsController extends Controller
         if (is_null($component = Component::find($componentId))) {
             return redirect()->route('components.index')->with('error', trans('admin/components/message.does_not_exist'));
         }
+        $min = $component->numCHeckedOut();
+        $validator = Validator::make($request->all(), [
+            "qty" => "required|numeric|gt:$min"
+        ]);
+
+        if ($validator->fails()) {
+            return redirect()->back()
+                ->withErrors($validator)
+                ->withInput();
+        }
 
         $this->authorize('update', $component);
 

app/Models/Component.php

@@ -155,6 +155,23 @@ class Component extends SnipeModel
         return $this->hasMany('\App\Models\Actionlog', 'item_id')->where('item_type', Component::class)->orderBy('created_at', 'desc')->withTrashed();
     }
 
+    /**
+     * Check how many items within a component are checked out
+     *
+     * @author [A. Gianotto] [<snipe@snipe.net>]
+     * @since [v5.0]
+     * @return int
+     */
+    public function numCheckedOut()
+    {
+        $checkedout = 0;
+        foreach ($this->assets as $checkout) {
+            $checkedout += $checkout->pivot->assigned_qty;
+        }
+
+        return $checkedout;
+    }
+
     /**
      * Check how many items within a component are remaining
      *
@@ -164,16 +181,7 @@ class Component extends SnipeModel
      */
     public function numRemaining()
     {
-        $checkedout = 0;
-
-        foreach ($this->assets as $checkout) {
-            $checkedout += $checkout->pivot->assigned_qty;
-        }
-
-
-        $total = $this->qty;
-        $remaining = $total - $checkedout;
-        return $remaining;
+        return $this->qty - $this->numCheckedOut();
     }
 
     /**

resources/lang/en/validation.php

@@ -44,6 +44,9 @@ return array(
     'exists'               => 'The selected :attribute is invalid.',
     'file'                 => 'The :attribute must be a file.',
     'filled'               => 'The :attribute field must have a value.',
+    'gt'                   => [
+        'numeric' => 'The :attribute field must be greater than :value.'
+    ],
     'hashed_pass'          => 'Your password is incorrect.',
     'image'                => 'The :attribute must be an image.',
     'in'                   => 'The selected :attribute is invalid.',