react-native.md

id	title	custom_edit_url	original_id
version-2.0.3-react-native	React Native	https://github.com/jaredpalmer/formik/edit/master/docs/guides/react-native.md	react-native

Formik is 100% compatible with React Native and React Native Web. However, because of differences between ReactDOM's and React Native's handling of forms and text input, there are some differences to be aware of. This section will walk you through them and what we consider to be best practices.

The gist

Before going any further, here's a super minimal gist of how to use Formik with React Native that demonstrates the key differences:

// Formik x React Native example
import React from 'react';
import { Button, TextInput, View } from 'react-native';
import { Formik } from 'formik';

export const MyReactNativeForm = props => (
  <Formik
    initialValues={{ email: '' }}
    onSubmit={values => console.log(values)}
  >
    {({ handleChange, handleBlur, handleSubmit, values }) => (
      <View>
        <TextInput
          onChangeText={handleChange('email')}
          onBlur={handleBlur('email')}
          value={values.email}
        />
        <Button onPress={handleSubmit} title="Submit" />
      </View>
    )}
  </Formik>
);

As you can see above, the notable differences between using Formik with React DOM and React Native are:

1. Formik's handleSubmit is passed to a <Button onPress={...} /> instead of HTML <form onSubmit={...} /> component (since there is no <form /> element in React Native).
2. <TextInput /> uses Formik's handleChange(fieldName) and handleBlur(fieldName) instead of directly assigning the callbacks to props, because we have to get the fieldName from somewhere and with React Native we can't get it automatically like in web (using input name attribute). You can also use setFieldValue(fieldName, value) and setFieldTouched(fieldName, bool) as an alternative.