I've dealt with such a guy during a freelance project. Heck my situation was worse. The boss and his whole team of 6 members were like an expired drug who couldn't even read the docs of a framework or language and would get excited and choose a framework in an (unstable) ver 0.1 for production env. Everytime I had to tell/explain the right way of doing things I had to explain to boss+6 guys. So I hit upon two options.
Let him run/test the web app or QUIT
Option-1: LET HIM RUN/test the webapp. When errors pop he'll surely come to you. Then explain the right way to him and don't tell him anything more than what he needs to know about the error. This is peaceful and will make your boss more happy that he has a guy who's capable of doing stuff. Days later you'll be called the hero who could do things the right way (yeah like Hancock coming thru the door and not breaking a wall to get in). I chose this. So now whenever there's anything wrong they call me for help even to this day long after the project is over.
Option-2: QUIT. There's no way you can work with these guys if you can't convince them.
I would suggest choosing the first option. Means a lot professionally.
Let him run/test the web app or QUIT
Option-1: LET HIM RUN/test the webapp. When errors pop he'll surely come to you. Then explain the right way to him and don't tell him anything more than what he needs to know about the error. This is peaceful and will make your boss more happy that he has a guy who's capable of doing stuff. Days later you'll be called the hero who could do things the right way (yeah like Hancock coming thru the door and not breaking a wall to get in). I chose this. So now whenever there's anything wrong they call me for help even to this day long after the project is over.
Option-2: QUIT. There's no way you can work with these guys if you can't convince them.
I would suggest choosing the first option. Means a lot professionally.