Improve object registry delete address issue #144

plexe/core/object_registry.py

@@ -111,18 +111,40 @@ def get_all(self, t: Type[T]) -> Dict[str, T]:
         """
         return {name: item.item for name, item in self._items.items() if name.startswith(str(t))}
 
-    def delete(self, t: Type[T], name: str) -> None:
+    def delete(self, t: Type[T], name: str, confirm: bool = False) -> None:
         """
         Delete an item by name.
 
         :param t: type prefix for the item
         :param name: the name of the item to delete
+        :param confirm: whether to show confirmation prompt (default: False for backward compatibility)
         """
         uri = self._get_uri(t, name)
+
         if uri in self._items:
+            item = self._items[uri]
+
+            if confirm:
+                print(f"About to delete: {uri}")
+                print(f"Item type: {type(item.item).__name__}")
+                print(f"Immutable: {item.immutable}")
+                response = input("Continue? (y/n): ")
+                if response.lower() != 'y':
+                    logger.info(f"Delete cancelled for: {uri}")
+                    return
+
             del self._items[uri]
+            logger.info(f"Registry: Deleted {uri}")
         else:
-            raise KeyError(f"Item '{uri}' not found in registry")
+            # Provide helpful error message with available items
+            similar_items = self.list_by_type(t)
+            if similar_items:
+                error_msg = f"Item '{uri}' not found. Available {t.__name__} items: {similar_items}"
+            else:
+                error_msg = f"No {t.__name__} items found in registry"
+
+            logger.warning(f"⚠️ {error_msg}")
+            raise KeyError(error_msg)
 
     def clear(self) -> None:
         """

plexe/ui/index.html

@@ -270,51 +270,74 @@
             const [messages, setMessages] = useState([]);
             const [input, setInput] = useState('');
             const [isLoading, setIsLoading] = useState(false);
+            const [userScrolledUp, setUserScrolledUp] = useState(false);
+            const [showScrollButton, setShowScrollButton] = useState(false);
             const messagesEndRef = useRef(null);
+            const messagesContainerRef = useRef(null);
 
             const scrollToBottom = () => {
                 messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' });
+                setShowScrollButton(false);
+            };
+
+            const handleScroll = (e) => {
+                const { scrollTop, scrollHeight, clientHeight } = e.target;
+                const isAtBottom = scrollHeight - scrollTop <= clientHeight + 10;
+                setUserScrolledUp(!isAtBottom);
             };
 
             useEffect(() => {
-                scrollToBottom();
-            }, [messages]);
+                if (messages.length > 0) {
+                    const lastMessage = messages[messages.length - 1];
+                    if (lastMessage.role === 'user') {
+                        // User sent message - always scroll to bottom
+                        scrollToBottom();
+                        setShowScrollButton(false);
+                    } else {
+                        // AI sent message - check if user scrolled up
+                        if (userScrolledUp) {
+                            setShowScrollButton(true);
+                        } else {
+                            scrollToBottom();
+                        }
+                    }
+                }
+            }, [messages, userScrolledUp]);
 
             useEffect(() => {
                 const unsubscribe = wsRuntime.subscribe((data) => {
                     if (data.type === 'status') return;
-
                     setMessages(prev => [...prev, {
                         id: data.id || Date.now().toString(),
                         role: data.role || 'assistant',
                         content: data.content
                     }]);
                     setIsLoading(false);
                 });
-
                 return unsubscribe;
             }, [wsRuntime]);
 
             const handleSubmit = (e) => {
                 e.preventDefault();
                 if (!input.trim() || isLoading) return;
-
                 const userMessage = {
                     id: Date.now().toString(),
                     role: 'user',
                     content: input.trim()
                 };
-
                 setMessages(prev => [...prev, userMessage]);
                 setInput('');
                 setIsLoading(true);
-
                 wsRuntime.send(userMessage.content);
             };
 
             return React.createElement('div', { className: 'flex flex-col h-full' },
                 // Messages area
-                React.createElement('div', { className: 'flex-1 overflow-y-auto p-4' },
+                React.createElement('div', {
+                    className: 'flex-1 overflow-y-auto p-4 relative',
+                    onScroll: handleScroll,
+                    ref: messagesContainerRef
+                },
                     messages.length === 0 && React.createElement('div', { className: 'text-center text-gray-500 mt-8' },
                         React.createElement('p', { className: 'text-lg mb-2' }, '👋 Hello! I\'m your Plexe Assistant.'),
                         React.createElement('p', { className: 'text-sm' }, 'I help you build machine learning models through natural conversation.'),
@@ -332,6 +355,11 @@
                     ),
                     React.createElement('div', { ref: messagesEndRef })
                 ),
+                // Scroll to bottom button
+                showScrollButton && React.createElement('button', {
+                    onClick: scrollToBottom,
+                    className: 'fixed bottom-20 right-4 bg-blue-500 text-white rounded-full p-3 shadow-lg hover:bg-blue-600 transition-colors z-10'
+                }, '↓'),
                 // Input area
                 React.createElement('form', { onSubmit: handleSubmit, className: 'border-t p-4' },
                     React.createElement('div', { className: 'flex space-x-2' },