Body: <p>We send out event registration links with checksums for our existing users.
  Those 'users' are kids who visit our summercamp. Their parents receive the email and register the kids with the personalised registration link.</p>
  
  <p>Now I was wondering, is there a way to 'log out'? the checksum login?
  With a variant of ?cid=0 (but that only works on an existing registration page an not in general. We have several different events going on)</p>
  
  <p>I'm asking because some parents go back in the form, change the name and think they register another kid, when instead they are changing the existing kid.</p>
  
  <p>Any help would be welcome!</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-01-31T22:37:48.740Z
Comments.Text: Is another way of saying this that you want the checksum to only be able to be used once?
Comments.UserDisplayName: petednz - fuzion
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-02-14T08:19:49.047Z
Comments.Text: Not really. We would like to offer a 'click here to register another child' link on the registration ThankYou page that invalidates/'logs out' the login by checksum (because of a registration link we sent by email)
Comments.UserDisplayName: Richard van Oosterhout
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-02-14T18:39:19.430Z
Comments.Text: I think that generally CiviCRM does not let the 'login' persist. I say that because we have had to force 'persist'. Therefore once the person has used their checksum link to register the first child, i would have thought if your directed them to a page where it said, do you want to register another child, it would log them out. Or if the problem is with them going back to the link in your email, would it work to give them two links. one with checksum 'for Johnny' and one without checksum for 'any other kids'?
Comments.UserDisplayName: petednz - fuzion
Tags: <civievent>
Title: How to invalidate (logout) a checksum login
ThreadText: # How to invalidate (logout) a checksum login
  
  (Asked by: username_0 on 2017-01-31)
  
  We send out event registration links with checksums for our existing users.
  Those 'users' are kids who visit our summercamp. Their parents receive the email and register the kids with the personalised registration link.
  
  Now I was wondering, is there a way to 'log out'? the checksum login?
  With a variant of ?cid=0 (but that only works on an existing registration page an not in general. We have several different events going on)
  
  I'm asking because some parents go back in the form, change the name and think they register another kid, when instead they are changing the existing kid.
  
  Any help would be welcome!
  
  **Tags:** civievent
  
  > **Comments:**
  > **username_1**: Is another way of saying this that you want the checksum to only be able to be used once?  
  > **username_0**: Not really. We would like to offer a 'click here to register another child' link on the registration ThankYou page that invalidates/'logs out' the login by checksum (because of a registration link we sent by email)  
  > **username_1**: I think that generally CiviCRM does not let the 'login' persist. I say that because we have had to force 'persist'. Therefore once the person has used their checksum link to register the first child, i would have thought if your directed them to a page where it said, do you want to register another child, it would log them out. Or if the problem is with them going back to the link in your email, would it work to give them two links. one with checksum 'for Johnny' and one without checksum for 'any other kids'?  
  
  ---
  
  ## 0 answers
  
  