I do this with our community, but we use Drupal and create an "organic group" for each event. We did some investigating of what it would take to migrate off Drupal and onto Wordpress, and group functionality was one of the difficult points.
In Wordpress, the closest I have found to this is the Group plugin. You could create a group for each event. Then you create a page or post for the event, and assign access to that page/post to the group.
You could write some small script to add users to a Group every time they register for an event. I would be inclined to do this via a nightly script, but you could also use CiviRules to automate creating the group every time a new event is created, and adding users every time they register.
If you name your event page/post as the event ID, you could even automate sending them an e-mail when they register to let them know the URL of the page. In fact, you could even automate creating the page and assigning access to the group.
Frankly you could automate the entire thing:
- When new event is created:
- Create new WP group, using event ID in the group name
- Create new WP page/post, using event ID in the page name
- Assign access to new page/post to group
- When user registers
- Add them to group
- Send them welcome email with private page URL
Someone who is familiar with coding using the Wordpress APIs should be able to do this without too much trouble. Coding this into a CiviRules rule or two would also be pretty easy.
(Having talked about scripts, I currently do the activities of setting up a new group and adding users who have registered to the group manually. Depending on your scale, it is not too time consuming.)