Mastering JavaScript Design Patterns

Command

The command pattern is a method of encapsulating both the parameters to a method and the current object state, and the method to be called. In effect, the command pattern packs up everything needed to call a method at a later date into a nice little package. Using this approach, one can issue a command and wait until a later date to decide which piece of code will execute the command. This package can then be queued or even serialized for later execution. Having a single point of command execution also allows us to easily add functionality such as undo or command logging.

This pattern can be a bit difficult to imagine, so let's break it down into its components, as shown in the following diagram:

The command message

The first component of ...