react-handler-hooks

🐱 react-handler-hooks

React hooks for persistent and parameterizable callbacks - useCallback on steroids!

Installation

npm i react-handler-hooks

yarn add react-handler-hooks

What are these?

Two hooks that fully replace the useCallback hook: useHandler and useParamsHandler. And they have many benefits!

Pros

• Hooks will return the same function on each render, this means children will never rerender because of a callback change.
• No dependency list needed, because hooks always use fresh callbacks internally. Your state values from useState will always be fresh in your callbacks.
• Supports passed parameters and they can even be dynamic.
• Full type safety with TypeScript.
• Optional dependency list, useful for render props.
• useHandler is fully reverse compatible with useCallback.
• Cleaner code, easier debugging, less headaches!

Cons

• useParamsHandler needs a unique key. You need to be cautious with it, just like with the key property for JSX elements.
• The hooks by themselves are technically (but barely) slower than useCallback, but they will give you the lost (and much more) performance back in lack of re-renders.

useHandler

Works and looks just like a normal useCallback, but you don't need to put dependencies.

useHandler(() => {
  // no params
});

useHandler((event: React.MouseEvent) => {
  // single param
});

useHandler((num: number, str: string) => {
 // two params etc...
});

const [clicks, setClicks] = useState<number>(0);
const [timestamp, setTimestamp] = useState<number>(0);

const onClick = useHandler((event: React.MouseEvent) => {
  // no need for function (clicks => clicks + 1) in setter
  // nor adding clicks to dep list!
  setClicks(clicks + 1);
  setTimestamp(Math.floor(event.timeStamp));
});

return (
  <h1 onClick={onClick}>
    Click count: {clicks} ({timestamp})
  </h1>
);

useParamsHandler

Allows for passing parameters that don't originate from the original callback. First parameter is a key or object with your params that has a key property. The hook returns a callback creator which returns the same callback for each unique key.

useParamsHandler((userId: string | number) => {
  // 1 passed param (which is the key)
});

useParamsHandler((params: { key: number, str: string }) => {
  // passed params object if you need multiple params
});

useParamsHandler((params: { key: string, num: number }, e: React.MouseEvent) => {
  // passed params and callback params
});

useParamsHandler((key: number, usersIds: string[], data: any) => {
 // 1 passed param and 2 callback params
});

const [clickedName, setClickedName] = useState<string>();
const [timestamp, setTimestamp] = useState<number>(0);

const onClick = useParamsHandler((name: string, event: React.MouseEvent) => {
  setClickedName(name);
  setTimestamp(Math.floor(event.timeStamp));
});

return (
  <>
    <h1 onClick={onClick('Ariel')}>
      Ariel
    </h1>
    <h1 onClick={onClick('John')}>
      John
    </h1>
    <h1 onClick={onClick('Mary')}>
      Mary
    </h1>
    {clickedName && `Clicked on ${clickedName} at ${timestamp}!`}
  </>
);

DependencyList

Both hooks support an optional second parameter with a DependencyList that is just like the DependencyList in useEffect, useLayoutEffect or useCallback.

This is only useful when you actually do want to get a brand new function into your child components. A very good examples are render props.

These hooks still have advantages over useCallback even if you're using a deplist, but they're mainly for you to not switch back between useCallback and these hooks.

Benchmark

Check out the benchmark folder.

Contact

E-mail: [e-mail]
Send me a nice message if you're using this!

License

MIT