Learning Python Design Patterns - Second Edition

Advantages and disadvantages of Command patterns

The Command pattern has the following advantages:

• It decouples the classes that invoke the operation from the object that knows how to execute the operation
• It allows you to create a sequence of commands by providing a queue system
• Extensions to add a new command is easy and can be done without changing the existing code
• You can also define a rollback system with the Command pattern, for example, in the Wizard example, we could write a rollback method

The following are the disadvantages of the Command pattern:

• There are a high number of classes and objects working together to achieve a goal. Application developers need to be careful developing these classes correctly.
• Every individual command is a ConcreteCommand ...