Efficiently define useCallback functions in React with loop-based parameters

Question

question

In React I do often need to use something like useCallback to remember a function in a list of items (created via a loop) to avoid single element occurrences due to reference identifier mismatches Change all components without re-rendering... Unfortunately, this is surprisingly hard to expire. For example, consider the following code:

const MyComp = memo({elements} => {
  {
    elements.map((elt, i) => {
      <>{elt.text}<Button onClick={(e) => dispatch(removeElement({id: i}))}> <>
    })
  }
})

Where Button is an external component provided by ant design, etc. This function reference will then be different on each render because it is inline, thus forcing a re-render.

A (Bad) Solution

To avoid this problem, I can think of another solution: create a new component MyButton, which accepts two properties index={i} and onClick instead of a single onClick and append the parameter index to any call to onClick:

const MyButton = ({myOnClick, id, ...props}) => {
  const myOnClickUnwrap = useCallback(e => myOnClick(e, id), [myOnClick]);
  return <Button onClick={myOnClickUnwrap} ...props/>
};

const MyComp = memo({elements} => {
  const myOnClick = useCallback((e, id) => dispatch(removeElement({id: id})), []);
  return 
    {
      elements.map((elt, i) => {
      <>{elt.text}<Button id={i} onClick={myOnClick}> <>
    })
  }
)

Why I want a better way

While this does work, it is very impractical for a number of reasons:

• Code confusion
• I would need to wrap all elements from external libraries like Button and rewrite components that were not originally intended to handle this nesting... This would break modularity and make the code more complex
• This combination is bad: if I wanted to nest elements in multiple lists, it would be even dirtier, since I would need to add a new index to each level of the list, like <MyButton index1= {index1} index2={index2} index3={index3 onClick={myFunction}>, which means I need to create a more complex version MyButton completely generic to check for nested levels quantity. I can't use index={[index1,index2,index3]} because this is an array and therefore has no stable reference.
• As far as I know, there is no naming convention for indexes, which means it is more difficult to share code or develop libraries between projects

Am I missing a better solution? Considering lists are everywhere, I can't believe there isn't a proper solution for this, and I'm surprised to see how little documentation there is on this.

edit I try to do this:

// Define once:
export const WrapperOnChange = memo(({onChange, index, Component, ...props}) => {
    const onChangeWrapped = useCallback(e => onChange(e, index), [onChange, index]);
    return <Component {...props} onChange={onChangeWrapped} />
});

export const WrapperOnClick = memo(({onClick, index, Component, ...props}) => {
    const onClickWrapped = useCallback(e => onClick(e, index), [onClick, index]);
    return <Component {...props} onClick={onClickWrapped} />
});

and use it like this:

const myactionIndexed = useCallback((e, i) => dispatch(removeSolverConstraint({id: i})), []);
return <WrapperOnClick index={i} Component={Button} onClick={myactionIndexed} danger><CloseCircleOutlined /></WrapperOnClick>

But it's still not perfect, in particular I need a wrapper for different nesting levels and I need to create a new version every time I target a new property (onClick, onChange,...), it doesn't work directly if I have multiple properties (e.g. onClick and onChange), I've never seen this before, so I guess there Better solution.

edit I tried various ideas, including using fast-memoize, but I still don't understand all the results: sometimes, fast-memoize works, sometimes it fails... and I don't know if fast-memoize is a recommended solution: It seems strange to use a third party tool for such a common use case. Check out my tests here https://codesandbox.io/embed/magical-dawn-67mgxp?fontsize=14&hidenavigation=1&theme=dark

Answer 1

1. First of all, it is not recommended to use index as a parameter or props or key, because when you delete the first one, all child components will be re-rendered.
2. And depending on your scenario if you want to avoid re-rendering, I have some ideas you can refer to, like this:

const WrapperEvent = (Component) => {
  return memo(function Hoc({ onClick, onChange, onOtherEvent, eventData, ...restProps }) {
    return (
      <Component onClick={() => onClick?.(eventData)} onChange={() => onChange?.(eventData)} onOtherEvent={() => onOtherEvent?.(eventData)} {...restProps} />
    )
  })
}

const WrapperButton = WrapperEvent(MyButton)

const Version2 = memo(({ deleteElement, elements }) => {
  return (
    <>
      <ul>
        {elements.map((e) => (
          <li key={e}>
            <Text>{e}</Text>{" "}
            <WrapperButton eventData={e} onClick={deleteElement}>Delete</WrapperButton>
          </li>
        ))}
      </ul>
    </>
  );
});

const initialState = ["Egg", "Milk", "Potatoes", "Tomatoes"].concat(
  [...Array(0).keys()].map((e) => e.toString())
);
export default function App() {
  const [elements, setElements] = useState(initialState);
  const restart = useCallback((e) => setElements(initialState), []);
  const deleteElement = useCallback(
    (name) => setElements((elts) => elts.filter((e, i) => e !== name)),
    []
  );
  return (
    <div className="App">
      <h1>Trying to avoid redraw</h1>
      <button onClick={restart}>Restart</button>
      <Version2 elements={elements} deleteElement={deleteElement} />
    </div>
  );
}

Test here https://codesandbox.io /s/sharp-wind-rd48q4?file=/src/App.js

Answer 2

Warning: I'm not a React expert (hence my question!), so please leave a comment below and/or add a 1 if you think this solution is the canonical way to do it in React (or -1 Not ^^). I'm also curious why some other solutions fail (e.g. based on proxy-memoize (which actually takes 10x longer than no caching, and doesn't cache at all) or fast-memoize (which doesn't always cache, depending on how I use it )), so if you know I'm interested in knowing)

Since I have little interest in this problem, I tried benchmarking a bunch of solutions (14!) against various options (no memory, using external libraries (fast memory vs. proxy memory), using wrappers), Using external components etc...

The best way seems to be to create a new component containing the entire element of the list , not just the last button. This allows for pretty clean code (even if I need to create two components for the list and the item, at least it makes sense semantically), avoids external libraries, and seems to be more efficient than everything else I've tried (at least in my opinion (for example):

const Version13Aux = memo(({ onClickIndexed, index, e }) => {
  const action = useCallback((e) => onClickIndexed(e, index), [
    index,
    onClickIndexed
  ]);
  return (
    <li>
      <Text>{e}</Text>
      <Button onClick={action}>Delete</Button>
    </li>
  );
});

const Version13 = memo(({ deleteElement, elements }) => {
  const actionOnClickIndexed = useCallback((e, i) => deleteElement(i), [
    deleteElement
  ]);
  return (
      <ul>
        {elements.map((e, i) => (
          <Version13Aux index={i} onClickIndexed={actionOnClickIndexed} e={e} />
        ))}
      </ul>
  );
});

I still don't really like this solution because I need to forward a lot of content from the parent component to the child component, but this seems to be the best solution I can get...

You can see a list of my attempts here, I used the code below. Here is the view from the profiler (technically the time difference between all versions is not that big (except version 7 which uses proxy-memoize, I removed it because it was longer, maybe 10x, and was being made Charts are harder to read), but I expect this difference to be greater on longer lists, where the items are more complex to draw (here I only have one text and one button). Note that all versions are not exactly the same (some use , some use , some normal lists, some Ant designed lists...), so time to compare It only makes sense between versions that do the same thing. Anyway, my main concern is to see what's cached and what's not cached, which is clearly visible in the profiler (light gray blocks are cached):

Another interesting fact is that you may want to benchmark before memorizing, as the improvement may not be significant, at least for simple components (size 5 here, just one text and one button).

import "./styles.css";
import { Button, List, Typography } from "antd";
import { useState, useCallback, memo, useMemo } from "react";
import { memoize, memoizeWithArgs } from "proxy-memoize";
import memoizeFast from "fast-memoize";
const { Text } = Typography;

const Version1 = memo(({ deleteElement, elements }) => {
  return (
    <>
      <h2>
        Version 1: naive version that should be inneficient (normal button)
      </h2>
      <p>
        Interestingly, since button is not a component, but a normal html
        component, nothing is redrawn.
      </p>
      <ul>
        {elements.map((e, i) => (
          <li>
            <Text>{e}</Text>{" "}
            <button onClick={(e) => deleteElement(i)}>Delete</button>
          </li>
        ))}
      </ul>
    </>
  );
});

const Version2 = memo(({ deleteElement, elements }) => {
  return (
    <>
      <h2>
        Version 2: naive version that should be inneficient (Ant design button)
      </h2>
      <p>
        Using for instance Ant Design's component instead of button shows the
        issue. Because onClick is inlined, the reference is different on every
        call which triggers a redraw.
      </p>
      <ul>
        {elements.map((e, i) => (
          <li>
            <Text>{e}</Text>{" "}
            <Button onClick={(e) => deleteElement(i)}>Delete</Button>
          </li>
        ))}
      </ul>
    </>
  );
});

const Version3AuxButton = memo(({ onClickIndexed, index }) => {
  const action = (e) => onClickIndexed(e, index);
  return <Button onClick={action}>Delete</Button>;
});

const Version3 = memo(({ deleteElement, elements }) => {
  const actionOnClickIndexed = useCallback((e, i) => deleteElement(i), [
    deleteElement
  ]);
  return (
    <>
      <h2>Version 3: works but really dirty (needs a new wrapper)</h2>
      <p>
        This works, but I don't like this solution because I need to manually
        create a new component, which makes the code more complicated, and it
        composes poorly since I need to create a new version for every
        nested-level.
      </p>
      <ul>
        {elements.map((e, i) => (
          <li>
            <Text>{e}</Text>
            <Version3AuxButton
              index={i}
              onClickIndexed={actionOnClickIndexed}
            />
          </li>
        ))}
      </ul>
    </>
  );
});

// We try to create a wrapper to automatically do the above code
const WrapperOnClick = memo(
  ({ onClickIndexed, index, Component, ...props }) => {
    const onClickWrapped = useCallback((e) => onClickIndexed(e, index), [
      onClickIndexed,
      index
    ]);
    return <Component {...props} onClick={onClickWrapped} />;
  }
);

const Version4 = memo(({ deleteElement, elements }) => {
  const actionOnClickIndexed = useCallback((e, i) => deleteElement(i), [
    deleteElement
  ]);
  return (
    <>
      <h2>Version 4: using a wrapper, it does work</h2>
      <p>
        Using a wrapper gives slightly less ugly code (at least I don’t need to
        redefine one wrapper per object), but still it’s not perfect (need to
        improve it to deal with nested level, different names (onChange,
        onClick, myChange…), multiple elements (what if you have both onClick
        and onChange that you want to update?), and still I don't see how to use
        it with List.item from Ant Design)
      </p>
      <ul>
        {elements.map((e, i) => (
          <li>
            <Text>{e}</Text>{" "}
            <WrapperOnClick
              Component={Button}
              index={i}
              onClickIndexed={actionOnClickIndexed}
            >
              Delete
            </WrapperOnClick>
          </li>
        ))}
      </ul>
    </>
  );
});

const Version5naive = memo(({ deleteElement, elements }) => {
  return (
    <>
      <h2>
        Version 5 naive: using no wrapper but List from Ant design. I don’t
        cache anything nor use usecallback: it does NOT work
      </h2>
      <p>
        Sometimes, with this version I got renders every second without apparent
        reason. Not sure why I don’t have this issue here.
      </p>
      <List
        header={<div>Header</div>}
        footer={<div>Footer</div>}
        bordered
        dataSource={elements}
        renderItem={(e, i) => (
          <List.Item>
            <Text>{e}</Text>{" "}
            <Button onClick={(e) => deleteElement(i)}>Delete</Button>
          </List.Item>
        )}
      />
    </>
  );
});

const Version5 = memo(({ deleteElement, elements }) => {
  const header = useMemo((e) => <div>Header</div>, []);
  const footer = useMemo((e) => <div>Footer</div>, []);
  const renderItem = useCallback(
    (e, i) => (
      <List.Item>
        <Text>{e}</Text>{" "}
        <Button onClick={(e) => deleteElement(i)}>Delete</Button>
      </List.Item>
    ),
    [deleteElement]
  );
  return (
    <>
      <h2>
        Version 5: like version 5 naive (using no wrapper but List from Ant
        design) with an additional useCallback: it does NOT work
      </h2>
      <p></p>
      <List
        header={header}
        footer={footer}
        bordered
        dataSource={elements}
        renderItem={renderItem}
      />
    </>
  );
});

const Version6 = memo(({ deleteElement, elements }) => {
  const header = useMemo((e) => <div>Header</div>, []);
  const footer = useMemo((e) => <div>Footer</div>, []);
  const actionOnClickIndexed = useCallback((e, i) => deleteElement(i), [
    deleteElement
  ]);
  const renderItem = useCallback(
    (e, i) => (
      <List.Item>
        <Text>{e}</Text>{" "}
        <WrapperOnClick
          Component={Button}
          index={i}
          onClickIndexed={actionOnClickIndexed}
        >
          Delete
        </WrapperOnClick>
      </List.Item>
    ),
    [actionOnClickIndexed]
  );
  return (
    <>
      <h2>Version 6: using a wrapper + List</h2>
      <p>
        This kind of work… at least the button seems to be cached, but not
        perfect as it shares all issues of the wrappers. I’m also unsure how to,
        e.g., memoize the whole item, and not just the button.
      </p>
      <List
        header={header}
        footer={footer}
        bordered
        dataSource={elements}
        renderItem={renderItem}
      />
    </>
  );
});

const Version7 = memo(({ deleteElement, elements }) => {
  const header = useMemo((e) => <div>Header</div>, []);
  const footer = useMemo((e) => <div>Footer</div>, []);
  const renderItem = useMemo(
    () =>
      // if we use memoizeWithArgs from proxy-memoize instead, the preprocessing is much longer
      //  and does not even work.
      memoizeWithArgs((e, i) => (
        <List.Item>
          <Text>{e}</Text>{" "}
          <Button onClick={(e) => deleteElement(i)}>Delete</Button>
        </List.Item>
      )),
    [deleteElement]
  );
  return (
    <>
      <h2>
        Version 7: using no wrapper but memoizeWithArgs from proxy-memoize: it
        does NOT work, wayyy longer than anything else.
      </h2>
      <p>
        I don't know why, but using proxy-memoize gives a much bigger render
        time, and does not even cache the elements.
      </p>
      <List
        header={header}
        footer={footer}
        bordered
        dataSource={elements}
        renderItem={renderItem}
      />
    </>
  );
});

const Version8 = memo(({ deleteElement, elements }) => {
  const header = useMemo((e) => <div>Header</div>, []);
  const footer = useMemo((e) => <div>Footer</div>, []);
  const renderItem = useMemo(
    () =>
      // if we use memoizeWithArgs from proxy-memoize instead, the preprocessing is much longer
      //  and does not even work.
      memoizeFast((e, i) => (
        <List.Item>
          <Text>{e}</Text>{" "}
          <Button onClick={(e) => deleteElement(i)}>Delete</Button>
        </List.Item>
      )),
    [deleteElement]
  );
  return (
    <>
      <h2>
        Version 8: using no wrapper but memoize from fast-memoize: it does work
      </h2>
      <p></p>
      <List
        header={header}
        footer={footer}
        bordered
        dataSource={elements}
        renderItem={renderItem}
      />
    </>
  );
});

const Version9 = memo(({ deleteElement, elements }) => {
  const computeElement = useMemo(
    () =>
      memoizeFast((e, i) => (
        <li>
          <Text>{e}</Text>{" "}
          <Button onClick={(e) => deleteElement(i)}>Delete</Button>
        </li>
      )),
    [deleteElement]
  );
  return (
    <>
      <h2>
        Version 9: like version 2, but use fast-memoize on whole element: does
        NOT work
      </h2>
      <p>I don't understand why this fails while Version 8 works.</p>
      <ul>{elements.map(computeElement)}</ul>
    </>
  );
});

const Version10 = memo(({ deleteElement, elements }) => {
  const del = useMemo(() => memoizeFast((i) => (e) => deleteElement(i)), [
    deleteElement
  ]);
  return (
    <>
      <h2>
        Version 10: like version 2 (+Text), but use fast-memoize only on delete
      </h2>
      <p>
        I don't understand why this fails while Version 8 works (but to be
        honest, I'm not even sure if it fails, since buttons sometimes just
        don't appear at all, while other renders from scratch without saying
        why): to be more precise, it does not involve caching from the library…
        or maybe this kind of cache is not shown by the tools since it is done
        by another external library? But then, why are the item grey in version
        8?
      </p>
      <ul>
        {elements.map((e, i) => (
          <li>
            <Text>{e}</Text> <Button onClick={del(i)}>Delete</Button>
          </li>
        ))}
      </ul>
    </>
  );
});

const Version11 = memo(({ deleteElement, elements }) => {
  const del = useMemo(() => memoizeFast((i) => (e) => deleteElement(i)), [
    deleteElement
  ]);
  const computeElement = useMemo(
    () =>
      memoizeFast((e, i) => (
        <li>
          <Text>{e}</Text> <Button onClick={del(i)}>Delete</Button>
        </li>
      )),
    [del]
  );
  return (
    <>
      <h2>Version 11: like version 9 + 10, does NOT work</h2>
      <p>Not sure why it fails, even worse than 9 and 10 separately.</p>
      <ul>{elements.map(computeElement)}</ul>
    </>
  );
});

const Version12 = memo(({ deleteElement, elements }) => {
  const MemoizedList = useMemo(
    () => () => {
      return elements.map((e, i) => (
        <li key={e}>
          <Text>{e}</Text>{" "}
          <Button onClick={(e) => deleteElement(i)}>Delete</Button>
        </li>
      ));
    },
    [elements, deleteElement]
  );
  return (
    <>
      <h2>Version 12: memoize the whole list: not what I want</h2>
      <p>
        Answer proposed in
        https://stackoverflow.com/questions/76446359/react-clean-way-to-define-usecallback-for-functions-taking-arguments-in-loop/76462654#76462654,
        but it fails as if a single element changes, the whole list is redrawn.
      </p>
      <ul>
        <MemoizedList />
      </ul>
    </>
  );
});

const Version13Aux = memo(({ onClickIndexed, index, e }) => {
  const action = useCallback((e) => onClickIndexed(e, index), [
    index,
    onClickIndexed
  ]);
  return (
    <li>
      <Text>{e}</Text>
      <Button onClick={action}>Delete</Button>
    </li>
  );
});

const Version13 = memo(({ deleteElement, elements }) => {
  const actionOnClickIndexed = useCallback((e, i) => deleteElement(i), [
    deleteElement
  ]);
  return (
    <>
      <h2>
        Version 13: simple list (not Ant): works but I don’t like the fact that
        we need to create auxiliary elements.
      </h2>
      <p>
        This works, but I don't like this solution because I need to manually
        create a new component, which can make the code more complicated.
      </p>
      <ul>
        {elements.map((e, i) => (
          <Version13Aux index={i} onClickIndexed={actionOnClickIndexed} e={e} />
        ))}
      </ul>
    </>
  );
});

const Version14Aux = memo(({ onClickIndexed, index, e }) => {
  const action = useCallback((e) => onClickIndexed(e, index), [
    index,
    onClickIndexed
  ]);
  return (
    <List.Item>
      <Text>{e}</Text> <Button onClick={action}>Delete</Button>
    </List.Item>
  );
});

const Version14 = memo(({ deleteElement, elements }) => {
  const actionOnClickIndexed = useCallback((e, i) => deleteElement(i), [
    deleteElement
  ]);

  const header = useMemo((e) => <div>Header</div>, []);
  const footer = useMemo((e) => <div>Footer</div>, []);
  const renderItem = useCallback(
    (e, i) => (
      <Version14Aux index={i} onClickIndexed={actionOnClickIndexed} e={e} />
    ),
    [actionOnClickIndexed]
  );
  return (
    <>
      <h2>Version 14: like version 13, but for Ant lists</h2>
      <p>
        This works, but I don't like this solution so much because I need to
        manually create a new component, which can make the code slightly more
        complicated. But it seems the most efficient solution (better than
        memoize etc), and the code is still not too bloated while avoiding third
        party libraries… So it might be the best solution.
      </p>
      <List
        header={header}
        footer={footer}
        bordered
        dataSource={elements}
        renderItem={renderItem}
      />
    </>
  );
});

const initialState = ["Egg", "Milk", "Potatoes", "Tomatoes"];
export default function App() {
  const [elements, setElements] = useState(initialState);
  const restart = useCallback((e) => setElements(initialState), []);
  const deleteElement = useCallback(
    (index) => setElements((elts) => elts.filter((e, i) => i !== index)),
    []
  );
  return (
    <div className="App">
      <h1>Trying to avoid redraw</h1>
      <button onClick={restart}>Restart</button>
      <Version1 elements={elements} deleteElement={deleteElement} />
      <Version2 elements={elements} deleteElement={deleteElement} />
      <Version3 elements={elements} deleteElement={deleteElement} />
      <Version4 elements={elements} deleteElement={deleteElement} />
      <Version5naive elements={elements} deleteElement={deleteElement} />
      <Version5 elements={elements} deleteElement={deleteElement} />
      <Version6 elements={elements} deleteElement={deleteElement} />
      <Version8 elements={elements} deleteElement={deleteElement} />
      <Version9 elements={elements} deleteElement={deleteElement} />
      <Version10 elements={elements} deleteElement={deleteElement} />
      <Version11 elements={elements} deleteElement={deleteElement} />
      <Version12 elements={elements} deleteElement={deleteElement} />
      <Version13 elements={elements} deleteElement={deleteElement} />
      <Version14 elements={elements} deleteElement={deleteElement} />
      {
        // Version 7 is soo long that I need to put it in the end or
        // on the profiler I can’t click on other items that
        // are too close to the scroll bar
        // <Version7 elements={elements} deleteElement={deleteElement} />
      }
    </div>
  );
}