NAME

       LWP::Authen::OAuth2::ServiceProvider::Google - Google OAuth2

VERSION

       version 0.20

SYNOPSIS

       See LWP::Authen::OAuth2 for basic usage.  The one general note is that "scope" is "scope" is optional in
       the specification, but required for Google.  Beyond that Google supports many client types, and their
       behavior varies widely.

       See <https://developers.google.com/accounts/docs/OAuth2> for Google's own documentation.  The
       documentation here is a Cliff Notes version of that, so look there for any necessary clarification.

REGISTERING

       Before you can use OAuth 2 with Google you need to register yourself as a client.  For that, go to
       <https://code.google.com/apis/console>.  Follow their directions to create a project, choose your "flow"
       (which is called your "client_type" in this document - look ahead for advice on available types), and
       then you'll be given a "client_id" and "client_secret".  If you're in the Login, WebServer or Client
       client types you'll also need to register a "redirect_uri" with them, which will need to be an
       "https://..." URL under your control.

       At that point you have all of the facts that you need to use this module.  Be sure to keep your
       "client_secret" secret - if someone else gets it and starts abusing it, Google reserves the right to
       block you.

       This module only handles the authorization step, after which it is up to you to figure out how to use
       whatever API you want to access.

CLIENT TYPES

       Google offers many client types.  Here is the status of each one in this module:

       Login
           This is for applications that want to let Google manage their logins.  See
           <https://developers.google.com/accounts/docs/OAuth2Login> for Google's documentation.

           This is not yet supported, and would require the use of JSON Web Tokens to support.

       Web Server Application
           This is intended for applications running on web servers, with the user sitting behind a browser
           interacting with you.  See <https://developers.google.com/accounts/docs/OAuth2WebServer> for Google's
           documentation.

           It can be specified in the constructor with:

               client_type => "web server",

           however that is not necessary since it is also the assumed default if no client_type is specified.

           After registering yourself as a client with Google, you will need to specify the "redirect_uri" as an
           https URL under your control.  If you just need this for one or two accounts there is no need to
           actually build anything at that URL - just go through the authorization as those accounts and grab
           your "code" from the URL.  If you will support many, making that URL useful is your responsibility.

           With this client type you are not guaranteed a refresh token, so the constructor does not require
           "client_id" and "client_secret".  (Passing them there is still likely to be convenient for you.)
           However there are several optional arguments available to "$oauth2->authorization_url(...)" that are
           worth taking note of:

           "access_type"
               Pass "access_type => "offline"," to "$oauth2-"request_tokens(...)> to request offline access.
               This means that you get a "refresh_token" which can be used to refresh the access token without
               help from the user.  The intent of this option is to support things like software that delays
               posting a blog entry until a particular time.

               In light testing this did not work for me until I passed the next argument, but then it worked
               perfectly.

           "approval_prompt"
               Pass "approval_prompt => "force"," to "$oauth2-"request_tokens(...)> to force the user to see the
               approval screen.  The default behavior without this is that the user sees the approval screen the
               first time through, and on subsequent times just gets an immediate redirect.

           "login_hint"
               If you think you know who the user is, you can pass an email in this parameter to let Google know
               which account you are trying to access.  Google thinks this may be helpful if someone is logged
               into multiple accounts at the same time.

       Client-side Application
           This client type is only for JavaScript applications.  See
           <https://developers.google.com/accounts/docs/OAuth2UserAgent> for Google's documentation.

           This is not supported since Perl is not JavaScript.

       Installed Application
           This client type is for applications that run on the user's machine, which can control a browser.
           See <https://developers.google.com/accounts/docs/OAuth2InstalledApp> for Google's documentation.

           It can be specified in the constructor with:

               client_type => "installed",

           On the first time it is the client's responsibility to open a browser and send the user to
           "$oauth2-"authorization_url(...)>.  If you pass in "redirect_uri => "http://localhost:$port"," then
           your application is expected to be listening on that port.  If you instead pass in "redirect_uri =>
           "urn:ietf:wg:oauth:2.0:oob"," then the code you need will be in the "title" inside of the page the
           browser is redirected to, and you'll need to grab it from there.

           The returned tokens always give you a refresh token, so you only have to go through this once per
           user.

           The only special authorization argument is "login_hint", which means the same thing that it does for
           webserver applications.

       Devices
           This client_type is for applications that run on the user's machine, which do not control a browser.
           See <https://developers.google.com/accounts/docs/OAuth2ForDevices> for Google's documentation.

           This client_type is not supported because I have not yet thought through how to handle the required
           polling step of setting up permissions.

       Service Account
           This client_type is for applications that login to the developer's account using the developer's
           credentials.  See <https://developers.google.com/accounts/docs/OAuth2ServiceAccount> for Google's
           documentation.

           This is not yet supported, and would require the use of JSON Web Tokens to support.

AUTHORS

       •   Ben Tilly, <btilly at gmail.com>

       •   Thomas Klausner <domm@plix.at>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2013 - 2022 by Ben Tilly, Rent.com, Thomas Klausner.

       This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5
       programming language system itself.