Fix upload cancellation by using refs instead of upload_controllers

reflex/.templates/web/utils/state.js

@@ -40,9 +40,6 @@ let event_processing = false;
 // Array holding pending events to be processed.
 const event_queue = [];
 
-// Pending upload promises, by id
-const upload_controllers = {};
-
 /**
  * Generate a UUID (Used for session tokens).
  * Taken from: https://stackoverflow.com/questions/105034/how-do-i-create-a-guid-uuid
@@ -485,7 +482,9 @@ export const uploadFiles = async (
     return false;
   }
 
-  if (upload_controllers[upload_id]) {
+  const upload_ref_name = `__upload_controllers_${upload_id}`
+
+  if (refs[upload_ref_name]) {
     console.log("Upload already in progress for ", upload_id);
     return false;
   }
@@ -537,7 +536,7 @@ export const uploadFiles = async (
   });
 
   // Send the file to the server.
-  upload_controllers[upload_id] = controller;
+  refs[upload_ref_name] = controller;
 
   try {
     return await axios.post(getBackendURL(UPLOADURL), formdata, config);
@@ -557,7 +556,7 @@ export const uploadFiles = async (
     }
     return false;
   } finally {
-    delete upload_controllers[upload_id];
+    delete refs[upload_ref_name];
   }
 };
 

reflex/components/core/upload.py

@@ -29,7 +29,7 @@
 from reflex.utils import format
 from reflex.utils.imports import ImportVar
 from reflex.vars import VarData
-from reflex.vars.base import CallableVar, LiteralVar, Var, get_unique_variable_name
+from reflex.vars.base import CallableVar, Var, get_unique_variable_name
 from reflex.vars.sequence import LiteralStringVar
 
 DEFAULT_UPLOAD_ID: str = "default"
@@ -108,7 +108,8 @@ def clear_selected_files(id_: str = DEFAULT_UPLOAD_ID) -> EventSpec:
     # UploadFilesProvider assigns a special function to clear selected files
     # into the shared global refs object to make it accessible outside a React
     # component via `run_script` (otherwise backend could never clear files).
-    return run_script(f"refs['__clear_selected_files']({id_!r})")
+    func = Var("__clear_selected_files")._as_ref()
+    return run_script(f"{func}({id_!r})")
 
 
 def cancel_upload(upload_id: str) -> EventSpec:
@@ -120,7 +121,8 @@ def cancel_upload(upload_id: str) -> EventSpec:
     Returns:
         An event spec that cancels the upload when triggered.
     """
-    return run_script(f"upload_controllers[{LiteralVar.create(upload_id)!s}]?.abort()")
+    controller = Var(f"__upload_controllers_{upload_id}")._as_ref()
+    return run_script(f"{controller}?.abort()")
 
 
 def get_upload_dir() -> Path: