How to extract Text from a formula field before trigger?

Question

I'm trying to populate a field whith several others. I know nothing about coding so ... After few research I did that:

1 trigger Updatelookup on Event (before insert, before update){
2    for (event u : Trigger.new){
3        u.lookup_contact__c = u.WhoId;
4        u.Subject = u.Nom_formate__c + u.Raison_visite_formate__c;
5          }
6  } 

The line 1, 2 and 3 works well. It populaite my custom lookup field from the WhoId lookup field (Yes it's possible to create custom lookup fiel in event now. but you have to ask to enable it)

My problem come with the line 4. Nom_formate__c is a formula field that take first and last name through the "lookup_contact__c". Because the WhoID lookup is populated after the triger, this part stay empty exept if I update the event.

So, I need to know if it have a way to do the triger after the formula is populated. (I have an error ir I write " after insert"

Thx a lot for your help

Answer 1

Wow didn't know you can add a custom lookup on Event - this is new. I think you should pull the Contact Info by code and not with the Formula (Unless it is and update Trigger - and this is non-issue since formula already been calculated). To do this: Create a new Contact Instance and query for the attached contact in your custom field.

/*Make sure you perform the query outside of the loop so you won't hit "Too many SOQL Limit" */

Contact c = [Select Id,FirstName,LastName From Contact Where Id =: lookup_contact__c];

Then just use those fields in your code:

u.subject = c.FirstName +" "+c.LastName;