</> `setError:` `(name: string, error: FieldError, { shouldFocus?: boolean }) => void`

The function allows you to manually set one or more errors.

Props

Name	Type	Description
`name`	string	input's name.
`error`	`{ type: string, message?: string, types: MultipleFieldErrors }`	Set an error with its type and message.
config	`{ shouldFocus?: boolean }`	Should focus the input during setting an error. This only works when the input's reference is registered, it will not work for custom register as well.

RULES

This method will not persist the associated input error if the input passes register's associated rules.

register('registerInput', { minLength: 4 }});
setError('registerInput', { type: 'custom', message: 'custom message' });
// validation will pass as long as minLength requirement pass

An error that is not associated with an input field will be persisted until cleared with clearErrors. This behaviour is only applicable for built-in validation at field level.
```
setError("notRegisteredInput", { type: "custom", message: "custom message" })
// clearErrors() need to invoked manually to remove that custom error
```
You can set a server or global error with root as the key. This type of error will not persist with each submission.
```
setError("root.serverError", {
  type: "400",
})
setError("root.random", {
  type: "random",
})
```
Can be useful in the handleSubmit method when you want to give error feedback to a user after async validation. (ex: API returns validation errors)
shouldFocus doesn't work when an input has been disabled.
This method will force set isValid formState to false, however, it's important to aware isValid will always be derived by the validation result from your input registration rules or schema result.
There are certain keyword which need to avoid before conflicting with type check. They are type, types

Examples:

Single Error

CodeSandbox ^TS

import * as React from "react"
import { useForm } from "react-hook-form"

type FormInputs = {
  username: string
}

const App = () => {
  const {
    register,
    handleSubmit,
    setError,
    formState: { errors },
  } = useForm<FormInputs>()
  const onSubmit = (data: FormInputs) => {
    console.log(data)
  }

  React.useEffect(() => {
    setError("username", {
      type: "manual",
      message: "Dont Forget Your Username Should Be Cool!",
    })
  }, [setError])

  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      <input {...register("username")} />
      {errors.username && <p>{errors.username.message}</p>}

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

Multiple Errors

CodeSandbox ^TS

import * as React from "react"
import { useForm } from "react-hook-form"

type FormInputs = {
  username: string
  firstName: string
}

const App = () => {
  const {
    register,
    handleSubmit,
    setError,
    formState: { errors },
  } = useForm<FormInputs>()

  const onSubmit = (data: FormInputs) => {
    console.log(data)
  }

  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      <label>Username</label>
      <input {...register("username")} />
      {errors.username && <p>{errors.username.message}</p>}
      <label>First Name</label>
      <input {...register("firstName")} />
      {errors.firstName && <p>{errors.firstName.message}</p>}
      <button
        type="button"
        onClick={() => {
          const inputs = [
            {
              type: "manual",
              name: "username",
              message: "Double Check This",
            },
            {
              type: "manual",
              name: "firstName",
              message: "Triple Check This",
            },
          ]

          inputs.forEach(({ name, type, message }) => {
            setError(name, { type, message })
          })
        }}
      >
        Trigger Name Errors
      </button>
      <input type="submit" />
    </form>
  )
}

Single Field Errors

import * as React from "react"
import { useForm } from "react-hook-form"

type FormInputs = {
  lastName: string
}

const App = () => {
  const {
    register,
    handleSubmit,
    setError,
    formState: { errors },
  } = useForm<FormInputs>({
    criteriaMode: "all",
  })

  const onSubmit = (data: FormInputs) => console.log(data)

  React.useEffect(() => {
    setError("lastName", {
      types: {
        required: "This is required",
        minLength: "This is minLength",
      },
    })
  }, [setValue])

  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      <label>Last Name</label>
      <input {...register("lastName")} />
      {errors.lastName && errors.lastName.types && (
        <p>{errors.lastName.types.required}</p>
      )}
      {errors.lastName && errors.lastName.types && (
        <p>{errors.lastName.types.minLength}</p>
      )}
      <input type="submit" />
    </form>
  )
}

Server Error

import * as React from "react";
import { useForm } from "react-hook-form";

const App = () => {
  const { register, handleSubmit, setError, formState: { errors } } = useForm({
    criteriaMode: 'all',
  });
  const onSubmit = async () => {
    const response = await fetch(...)
    if (response.statusCode > 200) {
        setError('root.serverError', {
          type: response.statusCode,
        })
    }
  }

  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      <label>Last Name</label>
      <input {...register("lastName")} />

      {errors.root.serverError.type === 400 && <p>server response message</p>}

      <button>submit</button>
    </form>
  );
};

Video

The following video explain setError API in detail.

Thank you for your support

If you find React Hook Form to be useful in your project, please consider to star and support it.

setError

</> setError: (name: string, error: FieldError, { shouldFocus?: boolean }) => void

Props

Video

Thank you for your support

</> `setError:` `(name: string, error: FieldError, { shouldFocus?: boolean }) => void`