클래스 사전<T>

라이브 collection 인스턴스가 변경될 때 호출될 리스너 callback 를 추가합니다.

참고

deletions and oldModificationsreport the indices in the collection before the change happened, while삽입andnewModificationsreport the indices into the new version of the collection. @throws A {@link TypeAssertionError} if콜백 is not a function. @example wines.addListener((collection, changes) => { // collection === wines console.log(${change.insertions.Length} 삽입); console.log(${changes.oldModifications.Length} oldModifications); console.log(${changes.newModifications.Length} newModifications); console.log(${changes.deletions.Length} 삭제); console.log(새로운 컬렉션 크기: ${collection.Length}); }); @example wines.addListener((collection, changes) => { console.log("A wine's brand might have changed"); }, ["brand"]); @note Adding the listener is an asynchronous operation, so the callback is invoked the first time to notify the caller when the listener has been added. Thus, when the callback is invoked the first time it will contain empty arrays for each property in the 변경 사항` 객체.

collection 인스턴스에서 모든 callback 리스너를 제거합니다.

collection 인스턴스에서 callback 리스너를 제거합니다.

스로우

TypeAssertionError callback 가 함수가 아닌 경우.