Apex Managed Sharing for detail object

Question

I am looking for a solution where I need to implement Apex Managed Sharing for a detail custom object whose master object is a standard object - in my case it is account.

I have an object say Meetings which has master-detail field which is set up with Account. I have done the apex managed sharing for a custom object but I am not sure how to proceed with this case. Few things I am curios about are:

1. When there is no apex sharing reason for standard objects how to proceed.
2. If there is no detail__Sharing table (meeting__share in my case) then how to develop.

It will be helpful if you can provide pseudocode for the same or a way to solve this.

Answer 1

You can't do it.

Master-detail follows the "all or nothing" philosophy.

All users who can see the master record (account) will be able to see all detail records (meetings). If they'll have right to edit - they'll be able to edit. (Well, of course assuming the Read & Edit checkboxes are selected on the profile but you get the idea). Etc. Simple really.

When you convert lookup to master-detail relationship these things happen:

1. OwnerId field disappears. This has some quite interesting impact on the business logic:
   • can't assign the records to queues
   • SF can't automatically assign them to current approver in approval processes _{(this doesn't seem like a big thing until the current approver needs to be able to edit that record to fix some data but the record is readonly for him; means some custom apex-managed sharing is needed to let him modify when he's the approver, revoke it when he's done...)}
   • all list views that relied on "My (meetings)", "My team's (meetings)" go bananas
   • same with reports
2. all sharing rules disappear
3. Meeting__Share table disappears too.

(Note that it's not the only situation where sharing rules & Meeting__Share will be invisible. Same happens if the object's Organization-Wide Defaults are set to "Public Read/Write").

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So - you need to get back to design phase. Do you need the Master-Detail in this relationship (rollup summaries, cascade delete, automatic sharing of detail records inherited from parent) or you need more fine-grained control but then you'll have to worry about all the components manually.

If you wish to stick to the M-D concept - write Apex-managed sharing code to share the master (Account) and maybe add some validations or something if you don't wish them to edit the accounts...