Using a custom widget causes re-render and loses focus

[macintushar]

Prerequisites

• I have searched the existing issues
• I understand that providing a SSCCE example is tremendously useful to the maintainers.
• I have read the documentation
• Ideally, I'm providing a sample JSFiddle, Codesandbox.io or preferably a shared playground link demonstrating the issue.

What theme are you using?

chakra-ui

Version

5.x

Current Behavior

I have added a custom widget. When I type in it in the form, it re-renders the field, which causes it to lose focus on the input field and moves the cursor's current position to the beginning of the input field. Note: If autofocus is not present in the input props, it completely loses focus and I can't type at all.

Screen.Recording.2024-09-12.at.12.03.24.PM.mov

Expected Behavior

Ideally, it should work the same way the default input function works. It shouldn't lose focus and shouldn't rerender.

Steps To Reproduce

1. Register a Custom Widget
2. Use custom widget in a form

Environment

- OS: macOS Sonoma
- Node: v22.3.0
- npm: 10.8.1

Anything else?

I followed the code written in the docs here
https://rjsf-team.github.io/react-jsonschema-form/docs/advanced-customization/custom-widgets-fields

[heath-freenome]

@macintushar Without looking at the code of your widget we can't help you. I'm guessing that having the field rerender itself is the cause of the issue. React is really picky about how rerenders work especially around focus/blur behaviors and how callbacks work. I would focus on that first

[macintushar]

Hey @heath-freenome, this is the code i'm using. It's from the docs.

const MyCustomWidget = (props: WidgetProps) => {
    return (
      <input
        type='text'
        className='custom'
        value={props.value}
        required={props.required}
        onChange={(event) => props.onChange(event.target.value)}
      />
    );
  };

  const widgets: RegistryWidgetsType = {
    customWidget: MyCustomWidget,
  };

Screen.Recording.2024-09-15.at.6.46.31.PM.mov

[macintushar]

Hey @heath-freenome, did you get some time to check out the issue? ^

[macintushar]

Hey @heath-freenome, could you please check this out? ^

[heath-freenome]

React can be picky about rendering when props change. The onChange is not a callback function so that might be the issue. How does this work?:

const MyCustomWidget = (props: WidgetProps) => {
    const { onChange, value, required } = props;
   const handler = React.useCallback((event) => onChange(event.target.value));
    return (
      <input
        type='text'
        className='custom'
        value={value}
        required={required}
        onChange={handler}
      />
    );
  };

  const widgets: RegistryWidgetsType = {
    customWidget: MyCustomWidget,
  };

[macintushar]

Hey @heath-freenome, I tested out the code you gave me with some minor changes to make it work properly (adding deps to useCallback), it seems to be working fine only if I use autoFocus as a prop. Please check out the two videos below to see what I mean:

Code v1:

  const MyCustomWidget = (props: WidgetProps) => {
    const { onChange, value, required } = props;
    const handler = useCallback((event) => onChange(event.target.value), [onChange]);
    return (
      <>
        <label>Custom Widget</label>
        <input
          type='text'
          className='custom'
          value={value}
          required={required}
          onChange={handler}
        />
      </>
    );
  };

Output for v1

Screen.Recording.2024-10-03.at.1.35.11.PM.mov

Code for v2

  const MyCustomWidget = (props: WidgetProps) => {
    const { onChange, value, required } = props;
    const handler = useCallback((event) => onChange(event.target.value), [onChange]);
    return (
      <>
        <label>Custom Widget</label>
        <input
          type='text'
          className='custom'
          value={value}
          required={required}
          onChange={handler}
          autoFocus
        />
      </>
    );
  };

Output for v2

Screen.Recording.2024-10-03.at.1.35.54.PM.mov

The diff between the two is only the autoFocus prop. It seems to loose focus anytime there is a change and the only reason it's working is because of the autoFocus. Is this expected behaviour?

Is there a way to get this to work without using the autoFocus prop?

[macintushar]

@heath-freenome noticed another issue.

If i use a Textarea instead of an input, it results in some pretty weird behavior. It sends my cursor to the first character position every time i type. Please check out the video below

Screen.Recording.2024-10-03.at.4.18.56.PM.mov

Code:

const MyCustomWidget = (props: WidgetProps) => {
    const { onChange, value, required } = props;
    const handler = useCallback(
      (event: { target: { value: any } }) => onChange(event.target.value),
      [onChange],
    );
    return (
      <>
        <label>Custom Widget</label>
        <textarea
          className='custom'
          value={value}
          required={required}
          onChange={handler}
          autoFocus
        />
      </>
    );
  };

[heath-freenome]

@macintushar Everything you are describing lends me to believe that something in how you are wrapping the Form is breaking the rules of React and causing the focus to be disrupted. I really do not have a lot of resources to help you debug this. Do you have a way to provide a reproducible test case using codesandbox.io?

[macintushar]

@heath-freenome this is for something on the Multiwoven platform. It is open source but it's difficult for me to run this on a codesanbox. I'm not sure how i'd be able to show you this occurring without me getting on a call or something with you. You can run our code locally to try and emulate my steps if required.

[macintushar]

I don't see any issues in the console w.r.t. React or me breaking the Rules of React with my code change. Please let me know how we can proceed further.

[macintushar]

@heath-freenome All I see is this in the console which seems related to RJSF. The ID error was due to something I was testing but the other two still remain.

Screen.Recording.2024-10-03.at.11.01.04.PM.mov