Proper way to use react-hook-form Controller with Material-UI Autocomplete

So, I fixed this. But it revealed what I believe to be an error in Autocomplete.

First... specifically to your issue, you can eliminate the MUI Error by adding a defaultValue to the <Controller>. But that was only the beginning of another round or problems.

The problem is that functions for getOptionLabel, getOptionSelected, and onChange are sometimes passed the value (i.e. the _id in this case) and sometimes passed the option structure - as you would expect.

Here's the code I finally came up with:

import React from "react";
import { useForm, Controller } from "react-hook-form";
import { TextField } from "@material-ui/core";
import { Autocomplete } from "@material-ui/lab";
import { Button } from "@material-ui/core";
export default function FormTwo({ options }) {
  const { register, handleSubmit, control } = useForm();

  const getOpObj = option => {
    if (!option._id) option = options.find(op => op._id === option);
    return option;
  };

  return (
    <form onSubmit={handleSubmit(data => console.log(data))}>
      <Controller
        name="country"
        as={
          <Autocomplete
            options={options}
            getOptionLabel={option => getOpObj(option).name}
            getOptionSelected={(option, value) => {
              return option._id === getOpObj(value)._id;
            }}
            renderInput={params => <TextField {...params} label="Country" />}
          />
        }
        onChange={([, obj]) => getOpObj(obj)._id}
        control={control}
        defaultValue={options[0]}
      />
      <Button type="submit">Submit</Button>
    </form>
  );
}

The accepted answer (probably) works for the bugged version of Autocomplete. I think the bug was fixed some time after that, so that the solution can be slightly simplified.

This is very useful reference/codesandbox when working with react-hook-form and material-ui: https://codesandbox.io/s/react-hook-form-controller-601-j2df5?

From the above link, I modified the Autocomplete example:

import TextField from '@material-ui/core/TextField';
import Autocomplete from '@material-ui/lab/Autocomplete';


const ControlledAutocomplete = ({ options = [], renderInput, getOptionLabel, onChange: ignored, control, defaultValue, name, renderOption }) => {
  return (
    <Controller
      render={({ onChange, ...props }) => (
        <Autocomplete
          options={options}
          getOptionLabel={getOptionLabel}
          renderOption={renderOption}
          renderInput={renderInput}
          onChange={(e, data) => onChange(data)}
          {...props}
        />
      )}
      onChange={([, data]) => data}
      defaultValue={defaultValue}
      name={name}
      control={control}
    />
  );
}

With the usage:

<ControlledAutocomplete
    control={control}
    name="inputName"
    options={[{ name: 'test' }]}
    getOptionLabel={(option) => `Option: ${option.name}`}
    renderInput={(params) => <TextField {...params} label="My label" margin="normal" />}
    defaultValue={null}
/>

control is from the return value of useForm(}

Note that I'm passing null as defaultValue as in my case this input is not required. If you'll leave defaultValue you might get some errors from material-ui library.

UPDATE:

Per Steve question in the comments, this is how I'm rendering the input, so that it checks for errors:

renderInput={(params) => (
                  <TextField
                    {...params}
                    label="Field Label"
                    margin="normal"
                    error={errors[fieldName]}
                  />
                )}

Where errors is an object from react-hook-form's formMethods:

const { control, watch, errors, handleSubmit } = formMethods