Did you inherit from EPiServer.Cms.TinyMce.Core.XhtmlStringEditorDescriptor ?
var content = metadata.FindOwnerContent();
also returns null?
I have no answer direct to you question, but it is a recommendation try using ContentArea and block type instead of the generic PropertyList as your current implementation, see https://world.optimizely.com/documentation/developer-guides/CMS/Content/Properties/generic-propertylist/
OK, I managed to fix this.
Solution would be available in CMS UI 11.36.2
Available here: https://nuget.optimizely.com/package/?id=EPiServer.CMS.UI&v=12.0.2
Let's say that I have two page content types PageA and PageB. Both of them are having property defined like that:
with OfferDetailsItem defined like that:
I would like to customize TinyMCE editor for Value property of OfferDetailsItem class. I would like to do this depending on page context so there is different toolbar config when its used on PageA and different when its used on PageB.
I tried to use CustomEditorDescriptor for XhtmlString TargetType and override:
but in this case metadata.Parent is null so I can't reach content page context. For properties that are not collections this is possible.
Do you know if there is any other way to deal with this?