Allow multiple 'Added By' for an activity
The way some clients are using the CRM, the 'Added By' person(s) is/are really the person(s) responsible for making the activity happen, and the 'Assigned To' are people that participate in the activity but are not directly responsible for it.
The issues is that the CRM only allows ONE Added By, so they rely on some custom contact reference fields 'Partnered With' to supplement the Added By. But this is not a good solution and has many limitations e,g not being able to see the activity in Partner tab etc.
Therefore the best way to move forward is to allow multiple 'Added By' for an activity. The database schema already allows for that with the activity_contact table.
From technical perspective, I reckon it was an oversight to not allow multiple contacts for Contact Source as we had moved civicrm_activity.source_contact_id (single), civicrm_activity_target.contact_id, civicrm_activity_assignee.contact_id (dropped civicrm_activity_target/civicrm_activity_assignee tables) in favor of civicrm_activity_contact table.
Screens that need to be modified:
- Activity tab in the Contact screen
- Activity View screen
- Activity Edit screen
- Activities reports
- Activities result