I’ve just been trying to figure out how to trigger some action on User creation. For example, imagine you want to make sure that a new user automatically follows some important folk in Chatter! (signed up yet?) It turns out to be a little tricky because the User object is a little special.

The documentation states that some objects “require that you perform DML operations on only one type per transaction” – the User object is one of these objects. So if I want to manipulate other objects (I do), I have to use a second method (that uses a @future).

Here’s the basic outline of what I did. Here’s the trigger, on a after insert of a User object:

Now all we need is to make sure that the addFriendstoUsers() uses the @future annotation:

As you can see, I’m not actually befriending the user – but I do create another record just to test that this all works. Which it appears to do!

Postscript

• Don’t forget about the Chatter Developer Preview Tech Talk on March 15
• Check out the An Introduction to Salesforce Chatter article for some real Chatter code snippets