feat: Enhance ConditionalRouterComponent with Regex Matching and UI Improvements (#5217)

* fix: revert response return type to Message for compatibility

* Change the max_iterations and case_sensitive advanced options

* feat: add regex matching and real-time refresh functionality

* Refactor evaluate_condition method to use elif statements for clarity

- Changed if statements to elif in the evaluate_condition method to improve readability and indicate mutually exclusive conditions.

- Removed redundant advanced=True line from BoolInput for case sensitivity.

* [autofix.ci] apply automated fixes

* Format code using make format

- Applied code formatting to ensure consistency and adherence to style guidelines.

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Eric Hare <ericrhare@gmail.com>

src/backend/base/langflow/components/logic/conditional_router.py

@@ -1,3 +1,5 @@
+import re
+
 from langflow.custom import Component
 from langflow.io import BoolInput, DropdownInput, IntInput, MessageInput, MessageTextInput, Output
 from langflow.schema.message import Message
@@ -27,16 +29,16 @@ class ConditionalRouterComponent(Component):
         DropdownInput(
             name="operator",
             display_name="Operator",
-            options=["equals", "not equals", "contains", "starts with", "ends with"],
+            options=["equals", "not equals", "contains", "starts with", "ends with", "matches regex"],
             info="The operator to apply for comparing the texts.",
             value="equals",
+            real_time_refresh=True,
         ),
         BoolInput(
             name="case_sensitive",
             display_name="Case Sensitive",
             info="If true, the comparison will be case sensitive.",
             value=False,
-            advanced=True,
         ),
         MessageInput(
             name="message",
@@ -49,6 +51,7 @@ class ConditionalRouterComponent(Component):
             display_name="Max Iterations",
             info="The maximum number of iterations for the conditional router.",
             value=10,
+            advanced=True,
         ),
         DropdownInput(
             name="default_route",
@@ -69,7 +72,7 @@ class ConditionalRouterComponent(Component):
         self.__iteration_updated = False
 
     def evaluate_condition(self, input_text: str, match_text: str, operator: str, *, case_sensitive: bool) -> bool:
-        if not case_sensitive:
+        if not case_sensitive and operator != "matches regex":
             input_text = input_text.lower()
             match_text = match_text.lower()
 
@@ -83,6 +86,11 @@ class ConditionalRouterComponent(Component):
             return input_text.startswith(match_text)
         if operator == "ends with":
             return input_text.endswith(match_text)
+        if operator == "matches regex":
+            try:
+                return bool(re.match(match_text, input_text))
+            except re.error:
+                return False  # Return False if the regex is invalid
         return False
 
     def iterate_and_stop_once(self, route_to_stop: str):
@@ -90,11 +98,10 @@ class ConditionalRouterComponent(Component):
             self.update_ctx({f"{self._id}_iteration": self.ctx.get(f"{self._id}_iteration", 0) + 1})
             self.__iteration_updated = True
             if self.ctx.get(f"{self._id}_iteration", 0) >= self.max_iterations and route_to_stop == self.default_route:
-                # We need to stop the other route
                 route_to_stop = "true_result" if route_to_stop == "false_result" else "false_result"
             self.stop(route_to_stop)
 
-    def true_response(self) -> Message | str:
+    def true_response(self) -> Message:
         result = self.evaluate_condition(
             self.input_text, self.match_text, self.operator, case_sensitive=self.case_sensitive
         )
@@ -103,9 +110,9 @@ class ConditionalRouterComponent(Component):
             self.iterate_and_stop_once("false_result")
             return self.message
         self.iterate_and_stop_once("true_result")
-        return ""
+        return Message(content="")
 
-    def false_response(self) -> Message | str:
+    def false_response(self) -> Message:
         result = self.evaluate_condition(
             self.input_text, self.match_text, self.operator, case_sensitive=self.case_sensitive
         )
@@ -114,4 +121,18 @@ class ConditionalRouterComponent(Component):
             self.iterate_and_stop_once("true_result")
             return self.message
         self.iterate_and_stop_once("false_result")
-        return ""
+        return Message(content="")
+
+    def update_build_config(self, build_config: dict, field_value: str, field_name: str | None = None) -> dict:
+        if field_name == "operator":
+            if field_value == "matches regex":
+                if "case_sensitive" in build_config:
+                    del build_config["case_sensitive"]
+            # Ensure case_sensitive is present for all other operators
+            elif "case_sensitive" not in build_config:
+                case_sensitive_input = next(
+                    (input_field for input_field in self.inputs if input_field.name == "case_sensitive"), None
+                )
+                if case_sensitive_input:
+                    build_config["case_sensitive"] = case_sensitive_input.to_dict()
+        return build_config