adjusted file_storage.py all() to handle class specifier

models/engine/file_storage.py

@@ -1,16 +1,23 @@
 #!/usr/bin/python3
 """This module defines a class to manage file storage for hbnb clone"""
 import json
+from console import HBNBCommand
 
 
 class FileStorage:
     """This class manages storage of hbnb models in JSON format"""
     __file_path = 'file.json'
     __objects = {}
 
-    def all(self):
-        """Returns a dictionary of models currently in storage"""
-        return FileStorage.__objects
+    def all(self, cls=None):
+        """Returns a dictionary of models (of a class) currently in storage"""
+        if cls in HBNBCommand.classes:
+            cls_dict = {key: value for key, value in
+                        FileStorage.__objects.items()
+                        if isinstance(value, cls)} 
+            return cls_dict
+        else:
+            return FileStorage.__objects
 
     def new(self, obj):
         """Adds new object to storage dictionary"""
@@ -48,3 +55,9 @@ def reload(self):
                     self.all()[key] = classes[val['__class__']](**val)
         except FileNotFoundError:
             pass
+
+    def delete(self, obj=None):
+        """Deletes object in database"""
+        if obj and obj in FileStorage.__objects:
+            del self.all()[obj.id]
+            self.save()