oox import/export of custom shape extrusion

[Miklos Vajna]

Hi Regina,

On Thu, Mar 18, 2021 at 04:24:38PM +0100, Regina Henschel <rb.henschel at t-online.de> wrote:
> I want to work on getting oox import/export of custom shape extrusion.

Great, much appreciated.

> In case a grabBag exists, it will be necessary to merge values from the
> internal "extrusion" property with values from the grabBag on export. In
> case no grabBag exists, writing OOXML from the internal properties is
> needed. In case no internal "extrusion" property exists, the current
> solution of writing the gragBag is OK.
> 
> Should I use separate solutions for the three cases? Advantage would be,
> that the development can be done without interfering the current solution
> for "only grabBag". But a solution for "merge" would be able to solve the
> situation "no grabBag" and "only grabBag" too, so doing only that might
> avoid code duplication.

The motivation bethind grab-bag is to preserve properties from OOXML,
which is not handled by libreoffice core. So in case there is a grab-bag
attached to a shape and you use the UI to modify the shape, it's
perfectly valid to just empty the grab-bag. This is predictable behavior
and you will never have to handle a mix of real document model and
grab-bag for the same shape.

As an example, we store smartart data in the shape grab-bag. But once
you edit the shape text, we empty the grab-bag, so your text edits are
not lost on save (since commit
a01ae07740e5c311fcc37f2ac2e2a0a2a1935920).

Does that help?

Regards,

Miklos