exchangeToken returns null

[confile]

I have a valid access token

def accessToken = facebookContext.user.token

When I request an exchange Token I got null

def exchangeToken = facebookContext.user.exchangeToken()

What do I have to do to get the exchange Token?

[benorama]

Indeed, exchangeToken() does not return any value. It sets the corresponding properties in ContextUser.

println "Old token $facebookContext.user.token"
println "Old expiration time ${new Date(facebookContext.user.tokenExpirationTime)}"

facebookContext.user.exchangeToken()

println "New token $facebookContext.user.token"
println "New expiration time ${new Date(facebookContext.user.tokenExpirationTime)}"

[confile]

@benorama

I use your code above and I get the following:

grails> Old token AAAEqZBHQL4O8BAMo1ZCaZABi0rZAUIRs3yZBsBrVBqPjOiQBvCZCIzNaqNnxIZCPqvcKr5cIZBZCEDYlVdByN4wJ3r1vAe7aMnVZBZCWlMEfHQBPgZDZD
grails> Old expiration time Sat Apr 06 00:24:14 CEST 2013
grails> New token AAAEqZBHQL4O8BAMo1ZCaZABi0rZAUIRs3yZBsBrVBqPjOiQBvCZCIzNaqNnxIZCPqvcKr5cIZBZCEDYlVdByN4wJ3r1vAe7aMnVZBZCWlMEfHQBPgZDZD
grails> New expiration time Sat May 25 17:27:01 CEST 2013

Why is the old and the new token the same? Is this correct?

[benorama]

May be the old token has been already exchanged? Could you try with a brand new Facebook session?

If you want to debug a token, you can use this great tool: https://developers.facebook.com/tools/debug/access_token

Enter the token, and it will give you the app/user/token and expiration info about this token.

[confile]

@benorama But when you look at the expiration time you see that they are different. How can this be even if the token is equal?

[benorama]

The first "old expiration time" is clearly not correct. How did you get it? Those value are stored in session server-side, there was perhaps a mismatch between old and new session.

You might start the authentication process from a fresh session (kill your cookies/browser) to see if you still have the issue.