What exactly does the parameter roomName in joinRoom(roomName) represent?
The joinRoom(roomName) may appear innocent at first look. One might think roomName must be a descriptive string that an application assigns to a room so users can distinguish each room. But in fact, the parameter roomName is instead a symbol for application to make the distinction. It is bound by the rule that it only accepts alphanumerical characters (A-Za-z_0-9). Because of the restriction an application should provide a mapping table to map the roomName used by Framework to the room name perceived by user. Suppose that we host a room whose topic is “Major League Baseball Playoff Talk”. A reasonable roomName used inside application may be mlbplayoff. At this point, the application has to provide a way to map these names so they are linked. Please See FAQ 3.2 for sample code.
