Update a more flexible way to customize folders accessibility (#19)

Author: bluehaha2

src/config/lfm.php

@@ -28,9 +28,11 @@
     // If true, share folder will be created when allow_multi_user is true.
     'allow_share_folder' => true,
 
-    // The database column to identify a user. Make sure the value is unique.
-    // Ex: When set to 'id', the private folder of user will be named as the user id.
-    'user_field' => 'id',
+    // Flexibla way to customize client folders accessibility
+    // Ex: The private folder of user will be named as the user id.
+    'user_field' => function() {
+        return empty(auth()->user()) ? '' : auth()->user()->id;
+    },
 
     /*
     |--------------------------------------------------------------------------

src/traits/LfmHelpers.php

@@ -378,9 +378,14 @@ public function sortFilesAndDirectories($arr_items, $sort_type)
 
     public function getUserSlug()
     {
-        $slug_of_user = config('lfm.user_field');
+        if (is_callable(config('lfm.user_field'))) {
+            $slug_of_user = call_user_func(config('lfm.user_field'));
+        } else {
+            $old_slug_of_user = config('lfm.user_field');
+            $slug_of_user = empty(auth()->user()) ? '' : auth()->user()->$old_slug_of_user;
+        }
 
-        return empty(auth()->user()) ? '' : auth()->user()->$slug_of_user;
+        return $slug_of_user;
     }
 
     public function error($error_type, $variables = [])