Improve Salesforce connection error handling and logging

app.py

@@ -36,9 +36,19 @@ class SalesforceDataLoader:
             return f"✅ Successfully connected to Salesforce as {username}", gr.update(visible=True), gr.update(choices=self.available_objects, value=None)
             
         except Exception as e:
-            logger.error(f"Connection failed: {str(e)}")
+            error_msg = str(e)
+            logger.error(f"Connection failed: {error_msg}")
             self.connected = False
-            return f"❌ Connection failed: {str(e)}", gr.update(visible=False), gr.update(choices=[], value=None)
+            
+            # Provide more helpful error messages
+            if "INVALID_LOGIN" in error_msg:
+                return f"❌ Invalid credentials. Please check your username, password, and security token.", gr.update(visible=False), gr.update(choices=[], value=None)
+            elif "API_DISABLED_FOR_ORG" in error_msg:
+                return f"❌ API access is disabled for your organization. Please contact your Salesforce admin.", gr.update(visible=False), gr.update(choices=[], value=None)
+            elif "LOGIN_MUST_USE_SECURITY_TOKEN" in error_msg:
+                return f"❌ Security token required. Please append your security token to your password.", gr.update(visible=False), gr.update(choices=[], value=None)
+            else:
+                return f"❌ Connection failed: {error_msg}", gr.update(visible=False), gr.update(choices=[], value=None)
     
     def _get_available_objects(self):
         """Get list of available Salesforce objects"""
@@ -50,9 +60,11 @@ class SalesforceDataLoader:
             for obj_name in common_objects:
                 try:
                     # Test if object exists and is accessible
-                    getattr(self.sf, obj_name).describe()
+                    obj = getattr(self.sf, obj_name)
+                    obj.describe()
                     self.available_objects.append(obj_name)
-                except:
+                except Exception as e:
+                    logger.debug(f"Object {obj_name} not accessible: {str(e)}")
                     continue
                     
         except Exception as e: