[QUESTION] Cannot read properties of undefined (reading 'value') - i18n locales

[Marcin Niedbalec]

I'd like to change the locale: "en" and "pl" but I occured an error Cannot read properties of undefined (reading 'value')
here

  const changeLanguage = e => {
> 63 |     const locale = e.target.value
     |                            ^
  64 |     router.push(router.pathname, router.asPath, { locale })
  65 |   }

changing the locale logic

const Navbar = props => {
  const { path } = props
  const router = useRouter()
  const { locale } = router
  const t = locale === 'en' ? en : pl

  const changeLanguage = e => {
    const locale = e.target.value
    router.push(router.pathname, router.asPath, { locale })
  }

Here is my Select component

<Select
  onChange={changeLanguage}
  defaultValue={locale}
  width="74px"
  display={{ base: 'none', md: 'inline-block' }}
  variant="outline"
  cursor="pointer"
  ml="30px"
  options={[
    {
      label: 'EN',
      value: 'en'
    },
    {
      label: 'PL',
      value: 'pl'
    }
  ]}
/>

the previous one chakra's one orginal which worked

<Select
  onChange={changeLanguage}
  defaultValue={locale}
  width="74px"
  display={{ base: 'none', md: 'inline-block' }}
  variant="outline"
  cursor="pointer"
  ml="30px"
  _focus={{
    boxShadow: 'teal'
  }}
>
  <option value="en">EN</option>
  <option value="pl">PL</option>
</Select>

[Chris Sandvik]

Unlike the Chakra UI Select which is a wrapper for the native HTML <select> element, this component doesn't return a change event (with how you're getting e.target.value). It instead just returns the object itself from your list of options. So in order for this to work right, you'll need to change your changeLanguage function like so:

/**
 * newLanguage = {
 *    label: 'EN',
 *    value: 'en'
 *  }
 */

const changeLanguage = newLanguage => {
  const locale = newLanguage.value; // <-- just .value not .target.value
  router.push(router.pathname, router.asPath, { locale })
}