Design Problems

• Avoiding Hard-Wired Requests
  • How can coupling the invoker of a request to a request be avoided?
• Exchanging Requests at Run-Time
  • How can an object be configured with a request?
  • How can a request be selected and exchanged at run-time?
• Queuing or Logging Requests
  • How can requests be queued or logged?
  • How can undoable operations be supported?