Merge branch 'master' into aarav_edit

1 files changed, 2 insertions, 1 deletions

diff --git a/src/client/views/collections/CollectionSubView.tsx b/src/client/views/collections/CollectionSubView.tsx
index bc7d6f897..e79d0a76d 100644
--- a/src/client/views/collections/CollectionSubView.tsx
+++ b/src/client/views/collections/CollectionSubView.tsx
@@ -58,6 +58,7 @@ export interface CollectionViewProps extends React.PropsWithChildren<FieldViewPr
     childOpacity?: () => number;
     childContextMenuItems?: () => { script: ScriptField; label: string }[];
     childLayoutTemplate?: () => Doc | undefined; // specify a layout Doc template to use for children of the collection
+    childRejectDrop?: (de: DragManager.DropEvent, subView?: DocumentView) => boolean; // whether a child document can be dropped on this document
     childHideDecorationTitle?: boolean;
     childHideResizeHandles?: boolean;
     childHideDecorations?: boolean;
@@ -323,7 +324,7 @@ export function CollectionSubView<X>() {
 
         protected onInternalDrop(e: Event, de: DragManager.DropEvent): boolean {
             const { docDragData } = de.complete;
-            if (docDragData && !docDragData.draggedDocuments.includes(this.Document)) {
+            if (docDragData && !docDragData.draggedDocuments.includes(this.Document) && !this._props.rejectDrop?.(de, this.DocumentView?.())) {
                 let added;
                 const dropAction = docDragData.dropAction || docDragData.userDropAction;
                 const targetDocments = DocListCast(this.dataDoc[this._props.fieldKey]);