How to leave a php application running on the client's pc even if the connection to the server goes down? [closed]

If you want to make your webapp available even if the server is off or the client is not using the internet, you must use HTML5 local storage . And of course, remember to only use local storage to save user data such as id, and user name, never save password or personal data. Remember to use javascript on the client to detect offline submissions ok?

What you want, is not easy to get. I understand the motivation (keep the application available when Internet or server fails) but the application architecture would have to be considerably more complex to achieve this result. Imagine for example the situation: the system falls out of the air, two users change the same register while the system is out. How will these conflicting changes be reconciled? It's a sample of the kind of thing a distributed system has to deal with.