momento_pattern

Memento Pattern

The Memento Pattern is a behavioral design pattern that allows an object to save and restore its previous state without exposing its internal structure. It is particularly useful for implementing undo/redo functionality, snapshots, or checkpoints in applications.

🔧 Structure

The Memento pattern consists of three main components:

• Originator:

  • The object whose state needs to be saved.
  • Creates a Memento containing a snapshot of its current state.
  • Can restore its state from a Memento.

• Memento:

  • A lightweight, immutable object that stores the state of the Originator.
  • Provides methods to retrieve the saved state (but only the Originator can modify it).

• Caretaker:

  • Manages and keeps track of multiple Mementos.
  • Never modifies or examines the contents of a Memento.
  • Requests a Memento from the Originator and stores it.
  • Can pass a Memento back to the Originator to restore its state.