Created
August 28, 2020 23:45
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useGlobalMemo is a React hook that lets you share memoizations across an entire app using a unique key.
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const cache = {} | |
export default function useGlobalMemo (key, fn, deps) { | |
if (!cache[key]) { | |
cache[key] = { | |
subs: 0, | |
deps, | |
value: fn(), | |
} | |
} else { | |
const oldDeps = cache[key].deps | |
if (oldDeps.length !== deps || oldDeps.some((d, i) => deps[i] !== d)) { | |
cache[key] = { | |
deps, | |
value: fn() | |
} | |
} | |
} | |
React.useEffect(() => { | |
cache[key].subs += 1 | |
return () => { | |
cache[key].subs -= 1 | |
if (!cache[key].subs) { | |
delete cache[key] | |
} | |
} | |
}, []) | |
return cache[key].value | |
} |
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there is a possible issue with
deps
, it would probably be better to replace deps with arevision
or aversion
key ( string | number ).the hook could also return a method to reset the cached method as well.