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useEffect

React.js docs for useEffect

Here's a simple example of how to use React's useState with useEffects.

Cleaning up an Effect

[@react.component] let make = () => { React.useEffect0(() => { let id = subscription.subscribe(); /* clean up the subscription */ Some(() => subscription.unsubscribe(id)); }); } 

Conditionally Firing an Effect

With this, the subscription will only be recreated when ~source changes

[@react.component] let make = (~source) => { React.useEffect1(() => { let id = subscription.subscribe(); /* clean up the subscription */ Some(() => subscription.unsubscribe(id)); }, [|source|]); }