If user-A uses my app and likes a post of user-B. But user-A has no active connection to the Internet. Is it best practice to just show him a message like "No connection to the internet" or should i cache his Interaction in some way and if he gets back online transmit it to the server ? Are there some good Tutorials out there which describe this Problem? I really want to know more about this Topic. Please tell me which approach you are using and how you implemented it ?
It depends a lot on your user experience design. Facebook messenger does not allow interaction without connection. Whatsapp let you text and will send the message when it gets online. You can either way, but it all depends on your application design and user experience.