# Method Web.Auth.OAuth2.Base()->refresh_access_token()

Method refresh_access_token

  ``string` refresh_access_token(`string` `oauth_token_uri`, `void`|`function`(``bool``, `string`:`void`) `async_cb`)`

Description

  Refreshes the access token, if a refresh token exists in the object.

Parameter `oauth_token_uri`

  Endpoint of the authentication service.

Parameter `async_cb`

  If given an async request will be made and this function will be called when the request is finished. The first argument passed to the callback will be `true` or `false` depending on if the request was successfull or not. The second argument will be a string. If the request failed it will be an error message. If it succeeded it will be the result as a string encoded with encode_value().