react hook form controller validation code example

Example 1: react-hook-form material-ui

import React from "react";
import { useForm, Controller } from "react-hook-form";
import Select from "react-select";
import Input from "@material-ui/core/Input";
import { Input as InputField } from "antd";

export default function App() {
  const { control, handleSubmit } = useForm();
  const onSubmit = data => console.log(data);

  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      <Controller as={Input} name="HelloWorld" control={control} defaultValue="" />
      <Controller as={InputField} name="AntdInput" control={control} defaultValue="" />
      <Controller
        as={Select}
        name="reactSelect"
        control={control}
        onChange={([selected]) => {
          // React Select return object instead of value for selection
          return { value: selected };
        }}
        defaultValue={{}}
      />

      <input type="submit" />
    </form>
  );
}

Example 2: react hook form rating material ui

import React, { useState } from "react";
import Checkbox from "@material-ui/core/Checkbox";
import Button from "@material-ui/core/Button";
import TextField from "@material-ui/core/TextField";
import FormControlLabel from "@material-ui/core/FormControlLabel";
import Typography from "@material-ui/core/Typography";
import { makeStyles } from "@material-ui/core/styles";
import Container from "@material-ui/core/Container";
import { useForm } from "react-hook-form";
import Rating from "@material-ui/lab/Rating";
import StarBorderIcon from '@material-ui/icons/StarBorder';

const useStyles = makeStyles((theme) => ({
  paper: {
    marginTop: theme.spacing(8),
    display: "flex",
    flexDirection: "column",
    alignItems: "center"
  },
  form: {
    width: "100%", // Fix IE 11 issue.
    marginTop: theme.spacing(1)
  },
  submit: {
    margin: theme.spacing(3, 0, 2)
  }
}));

export default function Create() {
  const classes = useStyles();
  const [rating, setRating] = useState(2);
  const { register, handleSubmit } = useForm();
  const onSubmit = (data) => {
    console.log(data);
  };

  return (
    <Container component="main" maxWidth="xs">
      <div className={classes.paper}>
        <Typography component="h1" variant="h5">
          Form
        </Typography>
        <form
          className={classes.form}
          noValidate
          onSubmit={handleSubmit(onSubmit)}
        >
          <TextField
            variant="outlined"
            margin="normal"
            fullWidth
            id="title"
            label="Title"
            name="title"
            autoFocus
            inputRef={register()}
          />
          <FormControlLabel
            control={
              <Checkbox
                inputRef={register}
                name="remember"
                defaultValue={false}
              />
            }
            label="remember"
          />
          <br />
          <FormControlLabel
            control={
              <>
                <input
                  name="rating"
                  type="number"
                  value={rating}
                  ref={register}
                  hidden
                  readOnly
                />
                <Rating
                  name="rating"
                  value={rating}
                  precision={0.5}
                  onChange={(_, value) => {
                    setRating(value);
                  }}
                  icon={<StarBorderIcon fontSize="inherit" />}
                />
              </>
            }
            label="select rating"
          />
          <Button
            type="submit"
            fullWidth
            variant="contained"
            color="primary"
            className={classes.submit}
          >
            Submit
          </Button>
        </form>
      </div>
    </Container>
  );
}

Example 3: how to use error in react hook form

import {useForm} from 'react-hook-form';
const {register,handleSubmit,formState: { errors }} = useForm();
<form onSubmit={handleSubmit(onSubmit)}>
<input name='to' placeholder="To" type="text" {...register("to",{ required: true })}/>
{errors.to && <p className="sendMail_error">To is required</p>}
 </form>