ENG-7732: plumb through Upload.on_drop_rejected (#5806)

Allow user to supply an event handler for dropped files that do not meet the
defined criteria.

By default it will display an error toast with the file names and rejection
reasons.

Author: masenf

pyi_hashes.json

@@ -19,7 +19,7 @@
   "reflex/components/core/helmet.pyi": "43f8497c8fafe51e29dca1dd535d143a",
   "reflex/components/core/html.pyi": "ea5919db8c8172913185977df900f36b",
   "reflex/components/core/sticky.pyi": "a9b4492e423f1dd4ccbf270c8ea90157",
-  "reflex/components/core/upload.pyi": "360fb929edf960aca289a37d0433fc38",
+  "reflex/components/core/upload.pyi": "77e828bbc55dd6593efdba1504e0cb5e",
   "reflex/components/core/window_events.pyi": "76bf03a273a1fbbb3b333e10d5d08c30",
   "reflex/components/datadisplay/__init__.pyi": "52755871369acbfd3a96b46b9a11d32e",
   "reflex/components/datadisplay/code.pyi": "b86769987ef4d1cbdddb461be88539fd",

reflex/components/core/upload.py

@@ -17,6 +17,7 @@
 from reflex.components.core.cond import cond
 from reflex.components.el.elements.forms import Input
 from reflex.components.radix.themes.layout.box import Box
+from reflex.components.sonner.toast import toast
 from reflex.constants import Dirs
 from reflex.constants.compiler import Hooks, Imports
 from reflex.environment import environment
@@ -36,7 +37,8 @@
 from reflex.vars import VarData
 from reflex.vars.base import Var, get_unique_variable_name
 from reflex.vars.function import FunctionVar
-from reflex.vars.sequence import LiteralStringVar
+from reflex.vars.object import ObjectVar
+from reflex.vars.sequence import ArrayVar, LiteralStringVar
 
 DEFAULT_UPLOAD_ID: str = "default"
 
@@ -178,6 +180,34 @@ def _on_drop_spec(files: Var) -> tuple[Var[Any]]:
     return (files,)
 
 
+def _default_drop_rejected(rejected_files: ArrayVar[list[dict[str, Any]]]) -> EventSpec:
+    """Event handler for showing a toast with rejected file info.
+
+    Args:
+        rejected_files: The files that were rejected.
+
+    Returns:
+        An event spec that shows a toast with the rejected file info when triggered.
+    """
+
+    def _format_rejected_file_record(rf: ObjectVar[dict[str, Any]]) -> str:
+        rf = rf.to(ObjectVar, dict[str, dict[str, Any]])
+        file = rf["file"].to(ObjectVar, dict[str, Any])
+        errors = rf["errors"].to(ArrayVar, list[dict[str, Any]])
+        return (
+            f"{file['path']}: {errors.foreach(lambda err: err['message']).join(', ')}"
+        )
+
+    return toast.error(
+        title="Files not Accepted",
+        description=rejected_files.to(ArrayVar)
+        .foreach(_format_rejected_file_record)
+        .join("\n\n"),
+        close_button=True,
+        style={"white_space": "pre-line"},
+    )
+
+
 class UploadFilesProvider(Component):
     """AppWrap component that provides a dict of selected files by ID via useContext."""
 
@@ -191,6 +221,9 @@ class GhostUpload(Fragment):
     # Fired when files are dropped.
     on_drop: EventHandler[_on_drop_spec]
 
+    # Fired when dropped files do not meet the specified criteria.
+    on_drop_rejected: EventHandler[_on_drop_spec]
+
 
 class Upload(MemoizationLeaf):
     """A file upload component."""
@@ -234,6 +267,9 @@ class Upload(MemoizationLeaf):
     # Fired when files are dropped.
     on_drop: EventHandler[_on_drop_spec]
 
+    # Fired when dropped files do not meet the specified criteria.
+    on_drop_rejected: EventHandler[_on_drop_spec]
+
     # Style rules to apply when actively dragging.
     drag_active_style: Style | None = field(default=None, is_javascript_property=False)
 
@@ -295,6 +331,10 @@ def create(cls, *children, **props) -> Component:
                 on_drop[ix] = event
             upload_props["on_drop"] = on_drop
 
+        if upload_props.get("on_drop_rejected") is None:
+            # If on_drop_rejected is not provided, show an error toast.
+            upload_props["on_drop_rejected"] = _default_drop_rejected
+
         input_props_unique_name = get_unique_variable_name()
         root_props_unique_name = get_unique_variable_name()
         is_drag_active_unique_name = get_unique_variable_name()
@@ -313,22 +353,22 @@ def create(cls, *children, **props) -> Component:
                 ),
             )
 
-        event_var, callback_str = StatefulComponent._get_memoized_event_triggers(
-            GhostUpload.create(on_drop=upload_props["on_drop"])
-        )["on_drop"]
-
-        upload_props["on_drop"] = event_var
+        event_triggers = StatefulComponent._get_memoized_event_triggers(
+            GhostUpload.create(
+                on_drop=upload_props["on_drop"],
+                on_drop_rejected=upload_props["on_drop_rejected"],
+            )
+        )
+        callback_hooks = []
+        for trigger_name, (event_var, callback_str) in event_triggers.items():
+            upload_props[trigger_name] = event_var
+            callback_hooks.append(callback_str)
 
         upload_props = {
             format.to_camel_case(key): value for key, value in upload_props.items()
         }
 
-        use_dropzone_arguments = Var.create(
-            {
-                "onDrop": event_var,
-                **upload_props,
-            }
-        )
+        use_dropzone_arguments = Var.create(upload_props)
 
         left_side = (
             "const { "
@@ -344,11 +384,10 @@ def create(cls, *children, **props) -> Component:
                 imports=Imports.EVENTS,
                 hooks={Hooks.EVENTS: None},
             ),
-            event_var._get_all_var_data(),
             use_dropzone_arguments._get_all_var_data(),
             VarData(
                 hooks={
-                    callback_str: None,
+                    **dict.fromkeys(callback_hooks, None),
                     f"{left_side} = {right_side};": None,
                 },
                 imports={