chinese work permit and residence permit

Hi, i was just offered to work in Shanghai as snr manager... my future employer told me to resign and then travel to Shanghai using tourist visa where they will help me to apply for work permit and residence permit. My wife has reminded me to get the work permit approved first prior resign current jobs ( as my contract mention for any reasons if i can get work permit, the work contract is null) please advise me possibility to get the work permit first in home country ?