Question

I try to post several scope values to allow my application for some google service…

I tried with two input field

<input type="hidden" name="scope" value="https://www.googleapis.com/auth/calendar" />  
<input type="hidden" name="scope" value="https://www.googleapis.com/auth/userinfo.email" />

and with one input field with + separator

<input type="hidden" name="scope" value="https://www.googleapis.com/auth/calendar+https://www.googleapis.com/auth/userinfo.email" />  

When I send my form with only one scope It work.
otherwise with sereval scope value google redirect me with this error description :

http://localhost:49972/redirect.aspx#error=invalid_request&error_description=OAuth+2+parameters+can+only+have+a+single+value:+scope&error_uri=http://code.google.com/apis/accounts/docs/OAuth2.html 

In the google getting started with oAuth2 it works with two scope values.

Here is my code :

  <form id="form1" method="post" action="https://accounts.google.com/o/oauth2/auth?" >
    <div>
        <input type="hidden" name="response_type" value="code" />
        <input type="hidden" name="client_id" value="my client id" />
        <input type="hidden" name="redirect_uri" value="http://localhost:49972/redirect.aspx" />
        <input type="hidden" name="scope" value="https://www.googleapis.com/auth/calendar" />
        <input type="hidden" name="scope" value="https://www.googleapis.com/auth/userinfo.email" />
        
        <input type="hidden" name="state" value="/profile" />
        <input type="submit" value="go" />
    </div>
    </form>

Answer 1

You were on the right track when you combined them to a single field
. There should be only one scope parameter in the request, with the values separated by spaces. If you’re putting it in a form like that, the browser will take care of encoding the space for you.

<input type="hidden" name="scope" value="https://www.googleapis.com/auth/calendar https://www.googleapis.com/auth/userinfo.email" />