API_IFCProperty missing deprecation mark | Alternative for AC29

[Emkave]

Hello guys. I was looking around the new Archicad API for AC29 and I noticed that they have removed API_IFCProperty for some reason. I checked the older API for AC28 and I found out that API_IFCProperty is not marked as deprecated or to be deleted in the future versions. Who can explain this weird discrepancy and what can I use instead of API_IFCProperty for AC29? 

[Hiromichi Shinkawa]

Hi, I'd like suggest you to check the following documentation for the changes. Also, you can check the example code (IFC_Test) in API29.

Archicad 29 C++ API: New API features in Archicad 29

HTH.

[petrvokoun]

We tested several approaches with our bimproject.cloud plugin in past 3 months.

If I understand it correctly, the old ACAPI_Element_GetIFCxxx set of calls were refering to the only existing "IFC storage" which is internal, user's. This worked until AC28 included. The new IFCAPI if referring to new "API-created" storage, which we had to create for this purpose. 

Lets say we create IFCProperty1 and IFCProperty2 with our plugin:

- both properties are not transferred with the injection tool

- if user changes value of IFCProperty1, it becomes the internal property:

-- we cannot edit it with plugin anymore

-- when user uses injection tool now, he gets only IFCProperty1 in the new element - the one he changed

so he basically has 2 different properties in his element shown, but they look similar and he cannot distinguish between them visually

Therefore we would have to tell the user: dont touch IFC properties we created by plugin + if you want them in another element instance, insert them again

This is also crippling the Undoable actions, because our own storage is isolated and not tracked 

The question is - do you guys know about it? Is it a bug or a purpose? What should we tell the users, that it will be fixed or they should work differently or that IFC Properties are deprecated in API in AC29 so they must use Classifications & Properties?