So if I have 2 custom content types book and review, I’d like a user(when viewing a specific book) to be able to create/attach a review to the book.
I’ve tried a few options.
1) Created a “create review” formblock and using panels made a custom node view panel for review, but I couldn’t get the relationship to work.
2) I also tried overriding comments on the book type with the node type review, the problem with this is I’d like users to be also be able to comment on the book and I couldn’t see the ability to add multiple comment types.
This seems pretty easy to do on node edit with node reference extension so I’m hoping this isn’t a big ask.
You need nodereference and nodereference_url modules.
You can simply create a nodereference field in your review content type, and configure it with nodereference_url widget.