Installation
@mantine/form
package does not depend on any other libraries, you can use it with or without @mantine/core
inputs:
yarn add @mantine/form
Usage
import { Button, Checkbox, Group, TextInput } from '@mantine/core';
import { useForm } from '@mantine/form';
function Demo() {
const form = useForm({
mode: 'uncontrolled',
initialValues: {
email: '',
termsOfService: false,
},
validate: {
email: (value) => (/^\S+@\S+$/.test(value) ? null : 'Invalid email'),
},
});
return (
<form onSubmit={form.onSubmit((values) => console.log(values))}>
<TextInput
withAsterisk
label="Email"
placeholder="your@email.com"
key={form.key('email')}
{...form.getInputProps('email')}
/>
<Checkbox
mt="md"
label="I agree to sell my privacy"
key={form.key('termsOfService')}
{...form.getInputProps('termsOfService', { type: 'checkbox' })}
/>
<Group justify="flex-end" mt="md">
<Button type="submit">Submit</Button>
</Group>
</form>
);
}
API overview
All examples below use the following example use-form hook.
import { useForm } from '@mantine/form';
const form = useForm({
mode: 'uncontrolled',
initialValues: {
path: '',
path2: '',
user: {
firstName: 'John',
lastName: 'Doe',
},
fruits: [
{ name: 'Banana', available: true },
{ name: 'Orange', available: false },
],
accepted: false,
},
});
Values
// get current form values
form.getValues();
// Set all form values
form.setValues(values);
// Set all form values using the previous state
form.setValues((prev) => ({ ...prev, ...values }));
// Set value of single field
form.setFieldValue('path', value);
// Set value of nested field
form.setFieldValue('user.firstName', 'Jane');
// Resets form values to `initialValues`,
// clears all validation errors,
// resets touched and dirty state
form.reset();
// Sets initial values, used when form is reset
form.setInitialValues({ values: 'object' });
List items
// Inserts given list item at the specified path
form.insertListItem('fruits', { name: 'Apple', available: true });
// An optional index may be provided to specify the position in a nested field.
// If the index is provided, item will be inserted at the given position.
// If the index is larger than the current list, the element is inserted at the last position.
form.insertListItem('fruits', { name: 'Orange', available: true }, 1);
// Removes the list item at the specified path and index.
form.removeListItem('fruits', 1);
// Swaps two items of the list at the specified path.
// You should make sure that there are elements at at the `from` and `to` index.
form.reorderListItem('fruits', { from: 1, to: 0 });
Validation
import { useForm } from '@mantine/form';
const form = useForm({
mode: 'uncontrolled',
initialValues: {
email: '',
user: {
firstName: '',
lastName: '',
},
},
validate: {
email: (value) => (value.length < 2 ? 'Invalid email' : null),
user: {
firstName: (value) =>
value.length < 2
? 'First name must have at least 2 letters'
: null,
},
},
});
// Validates all fields with specified `validate` function or schema, sets form.errors
form.validate();
// Validates single field at specified path, sets form.errors
form.validateField('user.firstName');
// Works the same way as form.validate but does not set form.errors
form.isValid();
form.isValid('user.firstName');
Errors
Validation errors occur when defined validation rules were violated, initialErrors
were specified in useForm properties
or validation errors were set manually.
// get current errors state
form.errors;
// Set all errors
form.setErrors({ path: 'Error message', path2: 'Another error' });
// Set error message at specified path
form.setFieldError('user.lastName', 'No special characters allowed');
// Clears all errors
form.clearErrors();
// Clears error of field at specified path
form.clearFieldError('path');
onReset and onSubmit
Wrapper function for form onSubmit
and onReset
event handler. onSubmit
handler accepts as second argument a function
that will be called with errors object when validation fails.
import { useForm } from '@mantine/form';
function Demo() {
const form = useForm({ mode: 'uncontrolled' });
const handleSubmit = (values: typeof form.values) => {
console.log(values);
};
return (
<>
{/* Supply handle submit as a single argument to receive validated values */}
<form onSubmit={form.onSubmit(handleSubmit)} />
{/* Supply second argument to handle errors */}
<form
onSubmit={form.onSubmit(
(values, event) => {
console.log(
values, // <- form.getValues() at the moment of submit
event // <- form element submit event
);
},
(validationErrors, values, event) => {
console.log(
validationErrors, // <- form.errors at the moment of submit
values, // <- form.getValues() at the moment of submit
event // <- form element submit event
);
}
)}
/>
{/* form.onReset calls form.reset */}
<form onReset={form.onReset}></form>
</>
);
}
Touched and dirty
// Returns true if user interacted with any field inside form in any way
form.isTouched();
// Returns true if user interacted with field at specified path
form.isTouched('path');
// Set all touched values
form.setTouched({ 'user.firstName': true, 'user.lastName': false });
// Clears touched status of all fields
form.resetTouched();
// Returns true if form values are not deep equal to initialValues
form.isDirty();
// Returns true if field value is not deep equal to initialValues
form.isDirty('path');
// Sets dirty status of all fields
form.setDirty({ 'user.firstName': true, 'user.lastName': false });
// Clears dirty status of all fields, saves form.values snapshot
// After form.resetDirty is called, form.isDirty will compare
// form.getValues() to snapshot instead of initialValues
form.resetDirty();
UseFormReturnType
UseFormReturnType
can be used when you want to pass form
as a prop to another component:
import { TextInput } from '@mantine/core';
import { useForm, UseFormReturnType } from '@mantine/form';
interface FormValues {
name: string;
occupation: string;
}
function NameInput({
form,
}: {
form: UseFormReturnType<FormValues>;
}) {
return (
<TextInput
key={form.key('name')}
{...form.getInputProps('name')}
/>
);
}
function OccupationInput({
form,
}: {
form: UseFormReturnType<FormValues>;
}) {
return (
<TextInput
key={form.key('occupation')}
{...form.getInputProps('occupation')}
/>
);
}
function Demo() {
const form = useForm<FormValues>({
mode: 'uncontrolled',
initialValues: { name: '', occupation: '' },
});
return (
<>
<NameInput form={form} />
<OccupationInput form={form} />
</>
);
}
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