fix: RangeCalendar external value updates (#851)

.changeset/selfish-boxes-cheat.md

@@ -0,0 +1,5 @@
+---
+"bits-ui": patch
+---
+
+fix: Range Calendar external value updates

packages/bits-ui/src/lib/bits/range-calendar/components/range-calendar.svelte

@@ -63,8 +63,6 @@
 		}
 	}
 
-	value === undefined && (value = { start: undefined, end: undefined });
-
 	const rootState = useRangeCalendarRoot({
 		id: box.with(() => id),
 		ref: box.with(

packages/bits-ui/src/lib/bits/range-calendar/range-calendar.svelte.ts

@@ -188,6 +188,23 @@ export class RangeCalendarRootState {
 			node.textContent = this.fullCalendarLabel;
 		});
 
+		/**
+		 * Synchronize the start and end values with the `value` in case
+		 * it is updated externally.
+		 */
+		$effect(() => {
+			const value = this.value.current;
+			untrack(() => {
+				if (value.start && value.end) {
+					this.startValue.current = value.start;
+					this.endValue.current = value.end;
+				} else if (value.start) {
+					this.startValue.current = value.start;
+					this.endValue.current = undefined;
+				}
+			});
+		});
+
 		/**
 		 * Synchronize the placeholder value with the current start value
 		 */