diff --git a/stand/tblctrl.py b/stand/tblctrl.py
index 5c956f8..0bc8166 100644
--- a/stand/tblctrl.py
+++ b/stand/tblctrl.py
@@ -1,7 +1,7 @@
 import cherrypy as cp
 
 from utils.dfh import DateFrameHolder
-from utils.st_utils import rerun
+from utils.st_utils import rerunall, get_session_ids
 
 
 @cp.expose
@@ -9,22 +9,33 @@ class TableController:
 
     def __init__(self):
         self.dfh = DateFrameHolder("output.h5")
-        self.sid = None
-        self.changed = True
+#        self.changed = True
+        self.sids = get_session_ids()
 
-    @property
-    def data(self):
-        self.changed = False
+    def get(self, sid):
+        changed = self.get_changed(sid)
+        data = self.get_data(sid)
+        return changed, data
+
+    def get_changed(self, sid):
+        return (sid in self.sids)
+
+    def get_data(self, sid):
+#        self.changed = False
+        try:
+            self.sids.remove(sid)
+        except KeyError as e:
+            if self.sids:
+                raise RuntimeError(f"{self.sids} is not empty") from e
         return self.dfh.df
 
-    @data.setter
-    def data(self, df):
+    def set_data(self, df):
         if self.dfh.df.equals(df):
             print("<<< skipping dump because dataframe did not change")
             return
         self.dfh.df = df
         self.dfh.dump()
-
+        self._trigger_changed()
 
     def GET(self):
         return str(self.dfh.df)
@@ -44,8 +55,9 @@ class TableController:
 
 
     def _trigger_changed(self):
-        self.changed = True
-        rerun(self.sid)
+#        self.changed = True
+        self.sids = get_session_ids()
+        rerunall()
 
 
 
diff --git a/stand/webapp.py b/stand/webapp.py
index 53d3f0b..1482240 100644
--- a/stand/webapp.py
+++ b/stand/webapp.py
@@ -24,10 +24,8 @@ st.set_page_config(
 hide_UI_elements()
 
 
-restapi.sid = get_session_id() # rest api needs current session ID to trigger the next rerun
-
-changed = restapi.changed
-df = restapi.data
+sid = get_session_id() # rest api needs current session IDs to trigger reruns
+changed, df = restapi.get(sid)
 
 
 download(df)
@@ -77,7 +75,7 @@ response = aggrid(
 
 new_df = response["data"]
 if not new_df.equals(df) and not changed:
-    restapi.data = new_df
+    restapi.set_data(new_df)
 
 
 print(">>> end of streamlit run")