ActionScript 3.0 Design Patterns

Information Shared Over the Internet | 483

TheRPSclass overrides thedoWinnermethod developed in theRefereeclass. The

other two methods in theRefereeclass are usable without any changes. A single

algorithm determines which side has won or if a tie occurred, and then transfers the

information into an array element that is then stored in a Stringvariable and

returned.

If you’re wondering whether it would be easier simply to make the

winnervariable a string and return it, you’re absolutely right. How-

ever, we liked the idea of being able to have a single array in one place

where you could add your own “smack” or “trash talk” to be dis-

played. So instead of simply displaying, “p1 Wins!” you could have

something like, “The Mighty Player 1 Conquers All!” Of course you

can be more creative than that.

When employing theRPSclass, we will observe the dictum to program to the inter-

face and not the implementation. So, in typing any instance where we would use the

RPSclass, we will type it asRefereeand instantiate it asRPS. (Look for this instantia-

tion of theRPS class in theSymPlayer1 andSymPlayer2 classes.)

Information Shared Over the Internet

At this point we need to take a little detour to discuss the techniques we used to send

data over the Internet for proxy work. As noted earlier in this chapter, we have chosen

to use Flash Media Server 2 to pass the move information from a player to its proxy

over the Internet. In order to see the relationships involved, we will show the purely

FMS2 server-side script and those portions of the player/proxy class that use it.

To begin, Example 13-4 shows theproxygame.ascfile (all lowercase). It is written in

ActionScript 1.0 because, at the time of this writing, all the code written for the

server-side could only be written in Server Side Communication ActionScript

(SSCA). The client-side counterpart is all ActionScript 3.0. This file sits in the server-

side location of the FMS2 host server. Generally, the host for the SWF files contain-

ing the compiled application and the server-side.ascfile are on the same host, but

not always. The connection to the server is through an RTMP protocol that’s part of

the client-side script.

gameOver=new Array("p1 Wins!","p2 Wins!","Tie!");
winNow=gameOver[winner];
return winNow;
}
}
}

Example 13-3. RPS.as (continued)