topic Changing elements in Archicad C++ API

Changing elements

vdentello — Mon, 16 Sep 2024 12:29:05 GMT

Hello! I've been struggling to make things work here.

The code builds, the command runs without trouble and I get the dialog at the end. But I get no changes to my element. can't figure out what's still missing. I've used most of the code from the examples.

I'm not using 'ACAPI_Element_Edit', cause I warns that:

No matching function for call to 'ACAPI_Element_Edit'

#include "basicgeometry.h"

void EditWall () { API_Element element, mask; API_ElementMemo memo; // GSErrCode err = NoError; element = {}; memo = {}; ACAPI_Element_Get (&element); ACAPI_Element_GetMemo (element.header.guid, &memo); ACAPI_ELEMENT_MASK_CLEAR (mask); ACAPI_ELEMENT_MASK_SET (mask, API_WallType, thickness); element.wall.thickness = 1.0; // ACAPI_Element_Edit(&element, &mask); ACAPI_Element_Change (&element, &mask, &memo, 0, true); DG::InformationAlert ("Exit", "Click ok to continue", "OK"); }

Re: Changing elements

BerndSchwarzenbacher — Fri, 20 Oct 2023 06:28:07 GMT

Hi Vítor,

The element.header.guid is empty since you didn't assign anything.
So both ACAPI_Element_Get and ACAPI_Element_GetMemo won't know which element to look for.
You'll have to get a guid of a wall first.

There are a lot of possibilities for this.

E.g. iterate through all walls with ACAPI_Element_GetElemList or get the guid from a selection with ACAPI_Selection_Get

There's a good code example for it on the linked documentation page.

The rest of your code seems fine for changing the wall thickness.

If you want to use ACAPI_Element_Edit you will have to pass different arguments as documented here: https://graphisoft.github.io/archicad-api-devkit/group___element.html#gaf661e412a0e3a3f6979444c67ec6d7f0

Best,
Bernd

Re: Changing elements

vdentello — Fri, 20 Oct 2023 18:36:12 GMT

It finally worked!
Another very important detail that was missing, from the beginning, was that it needs a ACAPI_CallUndoableCommand before everything, followed by a ACAPI_DisposeElemMemoHdls as it seems. Found many occurrences of this issue in the forum. I guess that should be more explicit within the first steps.

Re: Changing elements

poco2013 — Fri, 20 Oct 2023 21:18:06 GMT

Another point -- for cleaner code: API_ElementMemo is not required and should be replaced with nullptr. It's only required if your going to replace some of the attributes in the Memo structure.