Fix validate event (#338)

pynecone/components/component.py

@@ -157,9 +157,10 @@ class Component(Base, ABC):
         Raises:
             ValueError: If the value is not a valid event chain.
         """
-        # If it's already an event chain, return it.
-        if isinstance(value, Var):
-            return value
+        # If it's a custom component and var, return it.
+        if isinstance(self, CustomComponent):
+            if isinstance(value, Var):
+                return value
 
         arg = self.get_controlled_value()