org.elkoserver.server.context.mods
Class Census

java.lang.Object
  org.elkoserver.server.context.Mod
      org.elkoserver.server.context.mods.Census

All Implemented Interfaces:

Cloneable, DispatchTarget, Encodable, ContextMod, GeneralMod, ItemMod, UserMod

public class Census
extends Mod
implements GeneralMod

Mod to enable tracking a context's population. This mod may be attached to a context, user or item.

Constructor Summary

Census()
JSON-driven constructor.

Method Summary

void	census(User from) Message handler for the 'census' message.
JSONLiteral	encode(EncodeControl control) Encode this mod for transmission or persistence.

Methods inherited from class org.elkoserver.server.context.Mod

attachTo, clone, context, ensureHolding, ensureInContext, ensureReachable, ensureSameContext, ensureSameUser, holder, isEphemeral, markAsChanged, markAsEphemeral, object

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Census

@JSONMethod
public Census()

JSON-driven constructor.

Method Detail

encode

public JSONLiteral encode(EncodeControl control)

Encode this mod for transmission or persistence.

Specified by:

encode in interface Encodable

Parameters:

control - Encode control determining what flavor of encoding should be done.

Returns:

a JSON literal representing this mod.

census

@JSONMethod
public void census(User from)
            throws MessageHandlerException

Message handler for the 'census' message. This message requests the current number of users in the context where this mod resides.

recv: { to:REF, op:"census" }
send: { to:REF, op:"census", occupancy:int }

Parameters:

from - The user requesting the census.

Throws:

MessageHandlerException - if 'from' is not in the same context as this mod, or if this mod is attached to a user and 'from' is not that user.