Socket.io - 是否可以将回调函数作为套接字发出事件中的参数传递？

I was wondering if anyone knew if it was possible to pass callback functions in a socket.emit event? The reason I'm asking is I would like to pass some data as a parameter ONLY IF it has been uploaded in the form. To be more specific, a user can create a status that allows him to upload an image and a string of text IF he wants to but it is NOT REQUIRED. Is something like this possible... I was wondering if anyone knew if it was possib