Installation
Installing React Hook Form only takes a single command and you're ready to roll.
npm install react-hook-form
Example
The following code excerpt demonstrates a basic usage example:
import { useForm, SubmitHandler } from "react-hook-form"type Inputs = {example: stringexampleRequired: string}export default function App() {const {register,handleSubmit,watch,formState: { errors },} = useForm<Inputs>()const onSubmit: SubmitHandler<Inputs> = (data) => console.log(data)console.log(watch("example")) // watch input value by passing the name of itreturn (/* "handleSubmit" will validate your inputs before invoking "onSubmit" */<form onSubmit={handleSubmit(onSubmit)}>{/* register your input into the hook by invoking the "register" function */}<input defaultValue="test" {...register("example")} />{/* include validation with required or other standard HTML validation rules */}<input {...register("exampleRequired", { required: true })} />{/* errors will return when field validation fails */}{errors.exampleRequired && <span>This field is required</span>}<input type="submit" /></form>)}
React Web Video Tutorial
This video tutorial illustrates the basic usage and concepts of React Hook Form.
Register fields
One of the key concepts in React Hook Form is to register
your component into the hook. This will make its value available for both the form validation and submission.
Note: Each field is required to have a name
as a key for the registration process.
import ReactDOM from "react-dom"import { useForm, SubmitHandler } from "react-hook-form"enum GenderEnum {female = "female",male = "male",other = "other",}interface IFormInput {firstName: stringgender: GenderEnum}export default function App() {const { register, handleSubmit } = useForm<IFormInput>()const onSubmit: SubmitHandler<IFormInput> = (data) => console.log(data)return (<form onSubmit={handleSubmit(onSubmit)}><label>First Name</label><input {...register("firstName")} /><label>Gender Selection</label><select {...register("gender")}><option value="female">female</option><option value="male">male</option><option value="other">other</option></select><input type="submit" /></form>)}
Apply validation
React Hook Form makes form validation easy by aligning with the existing HTML standard for form validation.
List of validation rules supported:
- required
- min
- max
- minLength
- maxLength
- pattern
- validate
You can read more detail on each rule in the register section.
import { useForm, SubmitHandler } from "react-hook-form"interface IFormInput {firstName: stringlastName: stringage: number}export default function App() {const { register, handleSubmit } = useForm<IFormInput>()const onSubmit: SubmitHandler<IFormInput> = (data) => console.log(data)return (<form onSubmit={handleSubmit(onSubmit)}><input {...register("firstName", { required: true, maxLength: 20 })} /><input {...register("lastName", { pattern: /^[A-Za-z]+$/i })} /><input type="number" {...register("age", { min: 18, max: 99 })} /><input type="submit" /></form>)}
Integrating an existing form
Integrating an existing form should be simple. The important step is to register
the component's ref
and assign relevant props to your input.
import { Path, useForm, UseFormRegister, SubmitHandler } from "react-hook-form"interface IFormValues {"First Name": stringAge: number}type InputProps = {label: Path<IFormValues>register: UseFormRegister<IFormValues>required: boolean}// The following component is an example of your existing Input Componentconst Input = ({ label, register, required }: InputProps) => (<><label>{label}</label><input {...register(label, { required })} /></>)// you can use React.forwardRef to pass the ref tooconst Select = React.forwardRef<HTMLSelectElement,{ label: string } & ReturnType<UseFormRegister<IFormValues>>>(({ onChange, onBlur, name, label }, ref) => (<><label>{label}</label><select name={name} ref={ref} onChange={onChange} onBlur={onBlur}><option value="20">20</option><option value="30">30</option></select></>))const App = () => {const { register, handleSubmit } = useForm<IFormValues>()const onSubmit: SubmitHandler<IFormValues> = (data) => {alert(JSON.stringify(data))}return (<form onSubmit={handleSubmit(onSubmit)}><Input label="First Name" register={register} required /><Select label="Age" {...register("Age")} /><input type="submit" /></form>)}
Integrating with UI libraries
React Hook Form has made it easy to integrate with external UI component libraries. If the component doesn't expose input's ref
, then you should use the Controller component, which will take care of the registration process.
import Select from "react-select"import { useForm, Controller, SubmitHandler } from "react-hook-form"import { Input } from "@material-ui/core"interface IFormInput {firstName: stringlastName: stringiceCreamType: { label: string; value: string }}const App = () => {const { control, handleSubmit } = useForm({defaultValues: {firstName: "",lastName: "",iceCreamType: {},},})const onSubmit: SubmitHandler<IFormInput> = (data) => {console.log(data)}return (<form onSubmit={handleSubmit(onSubmit)}><Controllername="firstName"control={control}render={({ field }) => <Input {...field} />}/><Controllername="iceCreamType"control={control}render={({ field }) => (<Select{...field}options={[{ value: "chocolate", label: "Chocolate" },{ value: "strawberry", label: "Strawberry" },{ value: "vanilla", label: "Vanilla" },]}/>)}/><input type="submit" /></form>)}
Integrating Controlled Inputs
This library embraces uncontrolled components and native HTML inputs. However, it's hard to avoid working with external controlled components such as React-Select, AntD and MUI. To make this simple, we provide a wrapper component, Controller, to streamline the integration process while still giving you the freedom to use a custom register.
Using Component API
import { useForm, Controller, SubmitHandler } from "react-hook-form"import { TextField, Checkbox } from "@material-ui/core"interface IFormInputs {TextField: stringMyCheckbox: boolean}function App() {const { handleSubmit, control, reset } = useForm<IFormInputs>({defaultValues: {MyCheckbox: false,},})const onSubmit: SubmitHandler<IFormInputs> = (data) => console.log(data)return (<form onSubmit={handleSubmit(onSubmit)}><Controllername="MyCheckbox"control={control}rules={{ required: true }}render={({ field }) => <Checkbox {...field} />}/><input type="submit" /></form>)}
Using Hooks API
import * as React from "react"import { useForm, useController, UseControllerProps } from "react-hook-form"type FormValues = {FirstName: string}function Input(props: UseControllerProps<FormValues>) {const { field, fieldState } = useController(props)return (<div><input {...field} placeholder={props.name} /><p>{fieldState.isTouched && "Touched"}</p><p>{fieldState.isDirty && "Dirty"}</p><p>{fieldState.invalid ? "invalid" : "valid"}</p></div>)}export default function App() {const { handleSubmit, control } = useForm<FormValues>({defaultValues: {FirstName: "",},mode: "onChange",})const onSubmit = (data: FormValues) => console.log(data)return (<form onSubmit={handleSubmit(onSubmit)}><Input control={control} name="FirstName" rules={{ required: true }} /><input type="submit" /></form>)}
Integrating with global state
This library doesn't require you to rely on a state management library, but you can easily integrate with them.
import { useForm } from "react-hook-form"import { connect } from "react-redux"import updateAction from "./actions"export default function App(props) {const { register, handleSubmit, setValue } = useForm({defaultValues: {firstName: "",lastName: "",},})// Submit your data into Redux storeconst onSubmit = (data) => props.updateAction(data)return (<form onSubmit={handleSubmit(onSubmit)}><input {...register("firstName")} /><input {...register("lastName")} /><input type="submit" /></form>)}// Connect your component with reduxconnect(({ firstName, lastName }) => ({ firstName, lastName }),updateAction)(YourForm)
Handle errors
React Hook Form provides an errors
object to show you the errors in the form. errors
' type will return given validation constraints. The following example showcases a required validation rule.
import { useForm } from "react-hook-form"export default function App() {const {register,formState: { errors },handleSubmit,} = useForm()const onSubmit = (data) => console.log(data)return (<form onSubmit={handleSubmit(onSubmit)}><input{...register("firstName", { required: true })}aria-invalid={errors.firstName ? "true" : "false"}/>{errors.firstName?.type === "required" && (<p role="alert">First name is required</p>)}<input{...register("mail", { required: "Email Address is required" })}aria-invalid={errors.mail ? "true" : "false"}/>{errors.mail && <p role="alert">{errors.mail.message}</p>}<input type="submit" /></form>)}
Integrating with services
To integrate React Hook Form with a service, you can use the library's built-in submission handling. <Form />
component allow you to easily send form data to an API endpoint or other service. Find out more about Form component.
import { Form } from "react-hook-form"function App() {const { register, control } = useForm()return (<Formaction="/api/save" // Send post request with the FormData// encType={'application/json'} you can also switch to json objectonSuccess={() => {alert("Your application is updated.")}}onError={() => {alert("Submission has failed.")}}control={control}><input {...register("firstName", { required: true })} /><input {...register("lastName", { required: true })} /><button>Submit</button></Form>)}
Schema Validation
We also support schema-based form validation with Yup, Zod , Superstruct & Joi, where you can pass your schema
to useForm as an optional config. It will validate your input data against the schema and return with either errors or a valid result.
Step 1: Install Yup
into your project.
npm install @hookform/resolvers yup
Step 2: Prepare your schema for validation and register inputs with React Hook Form.
import { useForm } from "react-hook-form"import { yupResolver } from "@hookform/resolvers/yup"import * as yup from "yup"const schema = yup.object({firstName: yup.string().required(),age: yup.number().positive().integer().required(),}).required()export default function App() {const {register,handleSubmit,formState: { errors },} = useForm({resolver: yupResolver(schema),})const onSubmit = (data) => console.log(data)return (<form onSubmit={handleSubmit(onSubmit)}><input {...register("firstName")} /><p>{errors.firstName?.message}</p><input {...register("age")} /><p>{errors.age?.message}</p><input type="submit" /></form>)}
React Native
You will get the same performance boost and enhancement in React Native. To integrate with input component, you can wrap it with Controller
.
import { Text, View, TextInput, Button, Alert } from "react-native"import { useForm, Controller } from "react-hook-form"export default function App() {const {control,handleSubmit,formState: { errors },} = useForm({defaultValues: {firstName: "",lastName: "",},})const onSubmit = (data) => console.log(data)return (<View><Controllercontrol={control}rules={{required: true,}}render={({ field: { onChange, onBlur, value } }) => (<TextInputplaceholder="First name"onBlur={onBlur}onChangeText={onChange}value={value}/>)}name="firstName"/>{errors.firstName && <Text>This is required.</Text>}<Controllercontrol={control}rules={{maxLength: 100,}}render={({ field: { onChange, onBlur, value } }) => (<TextInputplaceholder="Last name"onBlur={onBlur}onChangeText={onChange}value={value}/>)}name="lastName"/><Button title="Submit" onPress={handleSubmit(onSubmit)} /></View>)}
TypeScript
React Hook Form is built with TypeScript
, and you can define a FormData
type to support form values.
import * as React from "react"import { useForm } from "react-hook-form"type FormData = {firstName: stringlastName: string}export default function App() {const {register,setValue,handleSubmit,formState: { errors },} = useForm<FormData>()const onSubmit = handleSubmit((data) => console.log(data))// firstName and lastName will have correct typereturn (<form onSubmit={onSubmit}><label>First Name</label><input {...register("firstName")} /><label>Last Name</label><input {...register("lastName")} /><buttontype="button"onClick={() => {setValue("lastName", "luo") // ✅setValue("firstName", true) // ❌: true is not stringerrors.bill // ❌: property bill does not exist}}>SetValue</button></form>)}
Design and philosophy
React Hook Form's design and philosophy focus on user and developer experience. The library aims to provide users with a smoother interaction experience by fine-tuning the performance and improving accessibility. Some of the performance enhancements include:
- Introducing form state subscription model through the proxy
- Avoiding unnecessary computation
- Isolating component re-rendering when required
Overall, it improves the user experience while users interact with the application. As for the developers, we introduce built-in validation and are closely aligned with HTML standards allowing further extension with powerful validation methods and integration with schema validation natively. In addition, having a strongly type-checked form with the help of typescript provides early build-time feedback to help and guide the developer to build a robust form solution.
The following talk given by Bill showcased some of the ideas and design patterns:
Thank you for your support
If you find React Hook Form to be useful in your project, please consider to star and support it.