I need to develop some new web parts for SharePoint 2013, and they should be developed in such a way that they can be easily migrated to SharePoint Online at a later point. The webparts need to ideally have custom properties for configuration. I'm looking for a good approach which will involve minimum migration effort later. As I understand, the ideal approach for webpart development now is to develop client web parts with SPFx, but SPFx cannot be used with SharePoint 2013. I'm thinking of the following options:
- Develop an Add-in part (Client Webpart). But the Add-in parts are rendered as Iframes and also I'm not sure if this is the way to go for future webpart development considering SPFx is now the modern framework for client webpart development.
So I'm a bit unsure which approach I should take. Any inputs about the options above or any other suggestions/hints would be greatly appreciated. Thanks a lot.