Socket.io-是否可以在套接字发出事件中将回调函数作为参数传递？

Question

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...

 // Client side code
 socket.emit('an event', required_data, function(){
   if(the string of text was included)
   {
      pass it as a parameter in the socket emit event
   }
 }, 
 function(){
    if(the image was included)
    {
      pass it as a parameter in the socket emit event
    }
 });

If anyone can offer some advice on how it can be done it would be appreciated. Regards,

Answer 1

I'm not realy sure what you want but as for an answer to your question title i would say yes you can have a callback to socket.emit like this

CLIENT :

socket.emit('event', data, function(response){
    do something
})

SERVER :

socket.on('event',function(data, fn) {
    // do whatever
    fn(response)     // callback of emit
})

Here whatever value you put as parameter 'response' in fn(response) would be available in clientside callback.