CSC152 2004F, Class 35: Weekly Project Discussion

Admin:
* It is bad to miss the weekly project discussion, even if you trust your groupmates (hint to BillupsM, ConorKev, BeckingE)
* Questions on the exam?  Tomorrow is your last real chance.
* Don't forget to vote!
* PolySci party tonight!
* Grade our homework, please!
  * Grade 223 exams
  * Prepare classes
  * Write paper
  * Grade 152 homework

Overview:
* Network group presents
* CRC card discussion

/Network Group/

* Code can be found in /home/poythres/CS152/Project
* Servers:
  * Create a ServerSocket
  * Accept on that socket
  * Build input and output
  * Use as normal.

/Sam attempts to record the board/

* UI communicates with anything that can implement the World interface
* Two implementations of World
  * The real implementation
  * The network client implementation
* World provides two important methods (so far)
  * interact(String actor, String verb)
  * interact(String actor, String verb, String object)
* UI reads user input, validates it, calls appropriate interact method
* Client packages up user input, sends it to server
* Server reads and unpackages users input, calls interact in RealWorld
* RealWorld validates action

* If the action fails, RealWorld throws an exception
* Server catches the exception and sends an exception object back to the client
* Client reads exception object and throws an exception
* UI catches exception and prints error message

* Suppose the action is SAM GET TAPE, which is legal
* RealWorld informs room that tape is no longer directly in the room (remove(thing))
  * How does room know what room Sam is in?
* RealWorld informs Sam that he now has the tape
* RealWorld identifies all the people in the room (by calling the contents() method) and tells them about the action.
  * We do this because the AI people will need to know about actions
* RealWorld tells all clients about the action (see below)
* RealWorld returns "Sam now has the tape" (or something similar) to server
* Server sends the reply back to client
* Client reads, unpacks, and returns to client.

* To inform all clients about an action, RealWorld calls the sendMessage() method in server.
* The server compiles a list of clients and sends a message to them
* Each client gets the message and calls the showMessage method in its corresponding user interface

* Rather than having methods that parse or unparse the action, we've decided to have a separate rebelsky.mug.Action object.