Created
June 22, 2023 04:43
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| import { useEffect, useMemo, useState } from 'react' | |
| import { Forest } from '@wonderlandlabs/forest' | |
| import { leafConfig, leafI } from '@wonderlandlabs/forest/lib/types' | |
| type configArray = [initializer: (...args: any) => leafConfig, ...rest: any]; | |
| export default function useForest<valueType>( | |
| config: leafConfig | configArray, | |
| onCreate?: (leaf: leafI) => unknown | |
| ) | |
| : [value: valueType, state: leafI] { | |
| // --- state is created here ---- | |
| const state = useMemo(() => { | |
| let initializer = config; | |
| if (Array.isArray(config)) { | |
| initializer = config[0](...config.slice(1)) | |
| } | |
| return new Forest(initializer); | |
| }, []); | |
| const [value, setValue] = useState<valueType>(state.value); | |
| // -- and two things happen here: | |
| // (1) the state output is subscribed to | |
| // (2) the opttional passed-through functioon is called with the state to "initialize" it. | |
| useEffect(() => { | |
| const sub = state.subscribe(setValue); | |
| let onComplete: unknown = null; | |
| if (onCreate) { | |
| // ---- for some bizarre reason this is getting called TWICE. | |
| onComplete = onCreate(state); | |
| } | |
| return () => { | |
| sub.unsubscribe() | |
| if (typeof onComplete === 'function') { | |
| onComplete(); | |
| } | |
| }; | |
| }, [state]); | |
| return [value, state]; | |
| } |
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