Programming Flash Communication Server

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Status and People List

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When the client disconnects, the server-side Status.removeClient( ) method is called.

It removes the entry for the client from the

status shared object:

this.so.setProperty(client.user.userName, null);

That was a fair bit to follow, and it’s easy to lose track of the big picture. In sum-

mary, the Status component’s addClient( ) method sets up each server-side

client

object so it can receive setStatus( ) calls from the client-side part of the Status compo-

nent. The addClient( ) method also updates the

status shared object so that the

user’s initial status is “Online”. From then on, whenever the user changes his status,

the series of events in Figure 13-4 will occur. Have a look at Figure 13-4 from top to

bottom to see how one event leads to another.

That’s it—you’ve seen all the pieces that make the Status component work. It’s time

to turn to designing and building the PeopleList component that will listen to the

status shared object and display the right icon for each user.

Designing and Building a PeopleList Component

The SimplePeopleList component introduced earlier was designed to be as simple as

possible in order to introduce the basic requirements of building a v2 Flash compo-

nent. It was not responsible for adding data to the

userList shared object and was

not capable of showing a user’s status. The PeopleList component addresses both

shortcomings. A server-side PeopleList object is used to maintain a

people shared

object to which the client-side PeopleList object connects (this replaces the

userList

used in the SimplePeopleList component). Furthermore, if a Status component

passes a reference to the

status shared object to the PeopleList component, the lat-

ter also displays status icons; otherwise, PeopleList works correctly without display-

ing any icons.

Fortunately, the code for the PeopleList.asc file, which implements the server-side

PeopleList class is short and relatively simple, as shown in Example 13-7.

Example 13-7. The server-side PeopleList class definition from the PeopleList.asc file

function PeopleList(name) {

if (!name) name = "main";

this.name = name;

this.path = "pfcs/" + this.className + "/" + name;

this.so = SharedObject.get(this.path + "/people");

}

PeopleList.prototype.className = "PeopleList";

PeopleList.prototype.addClient = function (client) {

this.so.setProperty(client.pfcs.user.userName, client.pfcs.user);

};

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Chapter 13: Building Communication Components

The server-side PeopleList class does two things. It adds an entry for each user into

the

people shared object when the client connects, and it removes the entry when the

client disconnects. The entry it adds is an object that was passed into the application.

onConnect( ) method. (See the main.asc file listing in Example 13-5.) Creating a sepa-

rate shared object for the PeopleList component makes it possible to separate the

public from the private information passed in by the client and reduce shared object

updates to those needed by just the PeopleList component. In this example, the

user

object is just added to the PeopleList’s people shared object. In later chapters, only

public information is added.

The PeopleList component does not receive remote method calls from its client-side

counterpart the way the Status component does. The shared object path is in the

now-familiar path of pfcs/PeopleList/main/people.

The client-side PeopleList component contains the same asset as the

SimplePeopleList component—a List component. Much of the code in the client-side

PeopleList component is the same as the code in the SimplePeopleList component,

so the entire class definition is not reproduced here. See the PeopleList.as file in the

PeopleList.zip archive on the book’s web site for the complete listing. The setter

method that is passed a NetConnection object is almost identical. The only differ-

ence is that it gets a shared object at the path

path + "people" instead of the path

resourcePath + "userList" used by the SimplePeopleList component. In either case,

the client-side PeopleList component uses the NetConnection object to get a refer-

ence to the remote shared object, sets itself as listener on it, and connects it. The Peo-

pleList class has an additional setter method that can be used to pass a reference to a

status_so shared object to it, as shown in the client-side code in Example 13-8.

PeopleList.prototype.removeClient = function (client) {

this.so.setProperty(client.pfcs.user.userName, null);

};

PeopleList.prototype.close = function ( ) {

};

Example 13-8. Passing in a status shared object to the PeopleList component

public function set status_so (so:SharedObject) {

if (so instanceof SharedObject) {

__status_so = so;

__status_so.addEventListener("onSync", this);

list.iconFunction = function (item) {

var status = item.data.status;

if (status) {

return "Status_Person_" + status;

}

};

if (__status_so.isConnected) {

Example 13-7. The server-side PeopleList class definition from the PeopleList.asc file (continued)