v1.0 .

app.py

@@ -4,38 +4,9 @@ import time
 import os
 from opcua_connector import opcua_connector
 
-class app:
-    def __init__(self):
-        self.app_cfg = yaml.safe_load(open('./cfg.yaml')) or {}
-        self.OPCon = opcua_connector(self.app_cfg)
-
-    def initialize_connection(self):
-        """Initialize OPC UA connection"""
-        try:
-            self.OPCon.connect()
-            if self.OPCon.check_connection() == 1:
-                st.session_state.connection_status = "Connected"
-                print("🎉 Connection initialized successfully")
-                return True
-            st.session_state.connection_status = "Disconnected"
-            return False
-        except Exception as e:
-            print(f"❌ Failed to initialize connection: {e}")
-            st.session_state.connection_status = "Disconnected"
-            return False
-
-    def execute_button_action(self, button_name):
-        """Execute button action with proper error handling"""
-        if button_name == 'INIT':
-            self.OPCon.adapt_access_rights()
-            print(f"🔧 INIT button pressed - Access rights adapted")
-        else:
-            self.OPCon.press_btn(button_name)
-            print(f"🔘 {button_name} button pressed")
-        return True
-
 # Load config early for password if present
-app = app()
+app_cfg = yaml.safe_load(open('./cfg.yaml')) or {}
+
 
 # Page configuration
 st.set_page_config(
@@ -49,11 +20,19 @@ st.set_page_config(
 with open('styles.css') as f:
     st.markdown(f"<style>{f.read()}</style>", unsafe_allow_html=True)
 
-# Initialize session state
+
-if 'connection_status' not in st.session_state:
+def execute_button_action(button_name):
-    st.session_state.connection_status = "Disconnected"
+    """Execute button action with proper error handling"""
-if 'authenticated' not in st.session_state:
+    if st.session_state.opcon is None:
-    st.session_state.authenticated = False
+        return False
+        
+    if button_name == 'INIT':
+        st.session_state.opcon.adapt_access_rights()
+        print(f"🔧 INIT button pressed - Access rights adapted")
+    else:
+        st.session_state.opcon.press_btn(button_name)
+        print(f"🔘 {button_name} button pressed")
+    return True
 
 # Re-validate connection status each render (do this before rendering UI)
 def is_opcua_connected(conn) -> bool:
@@ -61,10 +40,21 @@ def is_opcua_connected(conn) -> bool:
         return bool(conn and conn.check_connection() == 1)
     except Exception:
         return False
+    
 
+# Initialize session state
+if 'opcon' not in st.session_state:
+    st.session_state.opcon = None
+if 'connection_status' not in st.session_state:
+    st.session_state.connection_status = "Disconnected"
+
+# Update connection status on each render
 st.session_state.connection_status = (
-    "Connected" if is_opcua_connected(app.OPCon) else "Disconnected"
+    "Connected" if is_opcua_connected(st.session_state.opcon) else "Disconnected"
 )
+if 'authenticated' not in st.session_state:
+    st.session_state.authenticated = False
+
 
 
 
@@ -75,16 +65,31 @@ with st.sidebar:
     # Initialize button
     if st.button("🔌 Initialize Connection", use_container_width=True):
         with st.spinner("Initializing connection..."):
-            app.initialize_connection()
+            try:
+                if st.session_state.opcon is None:
+                    st.session_state.opcon = opcua_connector(app_cfg)
+                
+                st.session_state.opcon.connect()
+                if st.session_state.opcon.check_connection() == 1:
+                    st.session_state.connection_status = "Connected"
+                    print("🎉 Connection initialized successfully")
+                else:
+                    st.session_state.connection_status = "Disconnected"
+                    print("❌ Connection failed")
+            except Exception as e:
+                print(f"❌ Failed to initialize connection: {e}")
+                st.session_state.connection_status = "Disconnected"
             st.rerun()
     
     # Disconnect button
     if st.button("🔌 Disconnect", use_container_width=True):
         try:
-            app.OPCon.disconnect()
+            if st.session_state.opcon:
-            print("🔌 Disconnected from OPC UA server")
+                st.session_state.opcon.disconnect()
+                print("🔌 Disconnected from OPC UA server")
         except Exception as e:
             print(f"⚠️ Warning during disconnect: {e}")
+        st.session_state.opcon = None
         st.session_state.connection_status = "Disconnected"
         print("🔌 Connection reset")
         st.rerun()
@@ -96,7 +101,7 @@ with st.sidebar:
 # Password gate
 # Prefer cfg.yaml cred.dashboard.password, else env DASHBOARD_PASSWORD, else 'admin'
 expected_password = (
-    (app.app_cfg.get('cred', {}).get('dashboard', {}) or {}).get('password')
+    (app_cfg.get('cred', {}).get('dashboard', {}) or {}).get('password')
     or 'admin'
 )
 ui_locked = not st.session_state.authenticated
@@ -120,19 +125,19 @@ if not ui_locked:
 
     with btn_col1:
         if st.button("🔧\n\nINIT", key="init_btn", use_container_width=True, disabled=buttons_disabled):
-            app.execute_button_action('INIT')
+            execute_button_action('INIT')
 
     with btn_col2:
         if st.button("▶️\n\nSTART", key="start_btn", use_container_width=True, disabled=buttons_disabled):
-            app.execute_button_action('BTN_START')
+            execute_button_action('BTN_START')
 
     with btn_col3:
         if st.button("⏹️\n\nSTOP", key="stop_btn", use_container_width=True, disabled=buttons_disabled):
-            app.execute_button_action('BTN_STOP')
+            execute_button_action('BTN_STOP')
 
     with btn_col4:
         if st.button("🔄\n\nRESET", key="reset_btn", use_container_width=True, disabled=buttons_disabled):
-            app.execute_button_action('BTN_RESET')
+            execute_button_action('BTN_RESET')
 
     st.markdown('</div>', unsafe_allow_html=True)