main repo

node_modules/use-callback-ref/dist/es2019/useMergeRef.js

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+import * as React from 'react';
+import { assignRef } from './assignRef';
+import { useCallbackRef } from './useRef';
+const useIsomorphicLayoutEffect = typeof window !== 'undefined' ? React.useLayoutEffect : React.useEffect;
+const currentValues = new WeakMap();
+/**
+ * Merges two or more refs together providing a single interface to set their value
+ * @param {RefObject|Ref} refs
+ * @returns {MutableRefObject} - a new ref, which translates all changes to {refs}
+ *
+ * @see {@link mergeRefs} a version without buit-in memoization
+ * @see https://github.com/theKashey/use-callback-ref#usemergerefs
+ * @example
+ * const Component = React.forwardRef((props, ref) => {
+ *   const ownRef = useRef();
+ *   const domRef = useMergeRefs([ref, ownRef]); // 👈 merge together
+ *   return <div ref={domRef}>...</div>
+ * }
+ */
+export function useMergeRefs(refs, defaultValue) {
+    const callbackRef = useCallbackRef(defaultValue || null, (newValue) => refs.forEach((ref) => assignRef(ref, newValue)));
+    // handle refs changes - added or removed
+    useIsomorphicLayoutEffect(() => {
+        const oldValue = currentValues.get(callbackRef);
+        if (oldValue) {
+            const prevRefs = new Set(oldValue);
+            const nextRefs = new Set(refs);
+            const current = callbackRef.current;
+            prevRefs.forEach((ref) => {
+                if (!nextRefs.has(ref)) {
+                    assignRef(ref, null);
+                }
+            });
+            nextRefs.forEach((ref) => {
+                if (!prevRefs.has(ref)) {
+                    assignRef(ref, current);
+                }
+            });
+        }
+        currentValues.set(callbackRef, refs);
+    }, [refs]);
+    return callbackRef;
+}