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Cover image for Fixing `Deprecated: React.Ref.setCurrent`
Alain
Alain

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Fixing `Deprecated: React.Ref.setCurrent`

#reason #rescript #bucklescript

I keep finding myself having looking this up so I'm writing this note to myself.

Bad Code

This code throws a warning:

let useIsMounted = () => { let ref = React.useRef(false); React.useEffect0(() => { ref->React.Ref.setCurrent(true); Some(() => ref->React.Ref.setCurrent(false)); }); ref; };
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Warning 

Warning 3: deprecated: React.Ref.setCurrent Please directly assign to ref.current insteadocamllsp
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The Fix

In ReasonML/Reason-React

let useIsMounted = () => { let ref = React.useRef(false); React.useEffect0(() => { ref.current = true; Some(() => ref.current = false); }); ref; };
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In Rescript

let useIsMounted = () => { let ref = React.useRef(false) React.useEffect0(() => { ref.current = true Some(() => ref.current = false) }) ref }
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Yes, they are the same except for the commas which the compiler will remove for you anyway.

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