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Development of IFC 4.4
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Proposal to remove IfcApprovalRelationship and replace it with IfcRelNests #9

Open Moult opened 3 years ago

Moult commented 3 years ago

It seems to me that IfcApprovalRelationship does not serve any special purpose and could be generalised to IfcRelNests (or perhaps IfcRelAggregates?)

Can anybody confirm this, and spot if I have missed anything?

aothms commented 3 years ago

I think this applies to most of the resource level relationships. This has already been picked up by the IFC5 people, so now for 4.3 I don't think it requires our attention. Quite a few resources (looking at you IfcMaterial) will also be promoted to rooted things most likely so that a lot of the resource level relationships quite naturally disappear.

The only thing I'd say we can do for now is deprecate these, which I would support.

Moult commented 3 years ago

Ping @myoualid can you spot any reason why IfcApprovalRelationship still needs to exist, just in case I missed something?

If not, yes agree to deprecate. Thoughts, @berlotti ?

TLiebich commented 3 years ago

it is a broader issue caused by the strict separation of rooted and non-rooted entities. Agree with @aothms that this issues should be assigned to IFC5.

To @Moult - the nesting relationship only applies to rooted entities, and IfcApproval is not. This can be highly questionable, same with IfcMaterial, IfcCostValue, IfcProfile(Def), and finally IfcProperty (there is a similar issues about why IfcMaterial cannot be addressed directly under IfcContext using IfcRelDeclares).

not sure about deprecation - if doing so, several other resource relationships could fall into the same category. And if we keep IfcApproval (and someone wants to implement it for a use case) then there is the need to link two approvals ...

Moult commented 3 years ago

I've created a new "onhold" tag so that we can still keep track of, but skip issues that have wider implications and should be delayed until after 4.3.