I used to customize the list item forms (new/edit/display) in the farm solution which is quite straight forward. Now, I am working on a project which only allows sandboxed solutions to customize the list item forms. Obviously, I am no longer able to deploy the dll to the GAC or bin. I think of two solutions, one is to create a visual webpart which requires quite a bit of heavy lifting work. The other solution would be using InfoPath form which require less coding and has the flexibility of adding repeated sections. I kind of prefer the InfoPath form approach. But I am not sure whether there will be some kind of difficulties/limitations during the development.
Did anyone ever customize the list item forms in the sandboxed solutions? Could you share your experience?
Thanks,
Perry
The third option would be to deploy the custom list forms made with SharePoint Designer. For that you just need the limited web part manager plus you can manage the forms in a centralized place.
I wrote an article how making custom list forms centralized management back in 2011: http://www.n8d.at/blog/make-custom-list-forms-centralized-manageable/
It would be might a option too for your use case. Overwrite the OOTB list forms with a customized version.
greetings
Stefan