Best way to store Badge criteria?

Question

I've been thinking about how to implement the badge feature similar to SO's on a new website. What is the best way to store criteria for badges?

Two ideas:

• All code
• 'Second system' - create a meta architecture for defining badges and their criteria. Store some info in the database and have code query it to figure out the badges and their criteria.

Are there better ways?

Answer 1

Rules.

You create events in the system, and use rules within an event stream processor.

Specifically, say you have a badge "made 10 posts". You don't run "select count(*) from posts where user = :user" for every post. Rather, you have a simple rule that watches each post come by, and "count them", storing the rules state in the user profile.

That way "made 10 posts" is as cheap as "made 1,000,000" posts.

This also makes the system much more extensible.

Answer 2

I agree with Will on this one.

Create "events" over the pages so every time an event happens ie. a user deletes a post, it will query the event module with the event, lets say, EVENT_USER_DELETE_POST and then you can select that event and build a query based on it. You can then decide if a badge is awarded or not.

This will keep the two logics seperate and keep a modular design. It should be very easy to implement this way.

The only downside is that if the event was not "captured" then a user may well have earned a badge criteria but it has not yet been rewarded. However, this should never occur. The only situation I can think of is if the database is manipulated manually.