A ProxyCommand is a proxy that retrieve a Proxy before the execution of the execute method. A ProxyCommand must be subclassed, because the constructor need a proxyName.

When PureMVC instanciate the ProxyCommand, the Proxy is retrieved from the facade. If the proxyName is null, or if the corresponding Proxy doesn't exists, an Error is throw at Runtime.

Before the execution of the 'execute()' method, we know that the proxy has been successfully retrieved.

public class AddSecurityCommand extends ProxyCommand {

    public function AddSecurityCommand() {

    override public function execute(note : INotification) : void {
        /* At this point, we are sure that the instance variable 'proxy' 
         * contains a reference to the proxy named SecuritiesListProxy