Created
November 21, 2021 18:43
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useHistoryState.ts
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| import { useCallback, useState } from "react"; | |
| //value for the initial value, is either T or a function that returns T | |
| type InitialValueType<T> = T | ((prev?: T) => T); | |
| //the return value type it's an array with an element | |
| //of type T, a setter for the element, two functions (undo and redo) | |
| //the array of history and the current value | |
| type ReturnValueType<T> = [ | |
| T, | |
| (value: InitialValueType<T>) => void, | |
| () => void, | |
| () => void, | |
| InitialValueType<T>[], | |
| number | |
| ]; | |
| const useHistoryState: <T>( | |
| initialValue?: InitialValueType<T> | |
| ) => ReturnValueType<T> = <T>(initialValue?: InitialValueType<T>) => { | |
| const [state, _setState] = useState<T>(initialValue); | |
| const [history, setHistory] = useState<InitialValueType<T>[]>( | |
| initialValue !== undefined && initialValue !== null ? [initialValue] : [] | |
| ); | |
| const [pointer, setPointer] = useState<number>( | |
| initialValue !== undefined && initialValue !== null ? 0 : -1 | |
| ); | |
| const setState: (value: InitialValueType<T>) => void = useCallback( | |
| (value: InitialValueType<T>) => { | |
| let valueToAdd = value; | |
| if (typeof value === "function") { | |
| valueToAdd = (value as (prev?: T) => T)(state); | |
| } | |
| setHistory((prev) => [...prev.slice(0, pointer + 1), valueToAdd]); | |
| setPointer((prev) => prev + 1); | |
| _setState(value); | |
| }, | |
| [setHistory, setPointer, _setState, state, pointer] | |
| ); | |
| const undo: () => void = useCallback(() => { | |
| if (pointer <= 0) return; | |
| _setState(history[pointer - 1]); | |
| setPointer((prev) => prev - 1); | |
| }, [history, pointer, setPointer]); | |
| const redo: () => void = useCallback(() => { | |
| if (pointer + 1 >= history.length) return; | |
| _setState(history[pointer + 1]); | |
| setPointer((prev) => prev + 1); | |
| }, [pointer, history, setPointer]); | |
| return [state, setState, undo, redo, history, pointer]; | |
| }; | |
| export default useHistoryState; |
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