Need to get to fields from the Related To Object on both Tasks and Events

Question

I understand the polymorphic field issue around tasks and activities (sort of). I've been able to get around what I need using a custom report type so far, however, I now have a new requirement. I need to display a field that is on the Account record that the activity is related to and/or a checkbox field that is on the opportunity object that the task or event is related to. How can I do this? Thank you in advance for any help! I've not written a trigger but would be willing to try if I have guidance.

Answer 1

I'm afraid I still don't understand what exactly gives you trouble :/

I need to display a field that is on the Account record that the activity is related to and/or a checkbox field that is on the opportunity object that the task or event is related to.

Task and Event objects have these weird polymorphic fields WhoId/WhatId. But if you'll read the Task spec you'll realize there's a hidden field AccountId:

ID of the related Account. This is the account of WhatId if it exists, otherwise it’s the account of WhoId if it exists, otherwise it’s set to null.

So - even though the formula editor doesn't indicate it's possible - you can create custom field on activity of type formula and have there Account.Priority__c for example. And creation of such fields usually is easier than making a trigger to fill them in.

You can also access it in queries:

SELECT AccountId, Account.Name
FROM Task
WHERE WhatId = '0067000000AH3ME'

And last but not least - the standard "Activities with Opportunities" report type should out-of-the-box allow you to use Activity, Opportunity and Account fields in the report?

Have you tried making a report with filters "(Opportunity) Priority = true OR (Account) Priority = true"? The "OR" can be set by using the dropdown next to "Filter: Add" in the report builder, you need to select "Filter logic".

Answer 2

Use Describe results to determine what the RelatedTo ID type is...

i.e.

if(t.WhatID != null){
   if( ( (String)t.whatID).startsWith(Account.sObjectType.getDescribe().getKeyPrefix()){
        //This is an account, process here
   }else if( ( (String)t.whatID).startsWith(Opportunity.sObjectType.getDescribe().getKeyPrefix()){
         //This is an Opportunity process here
   }
}