Best design pattern for "undo" feature

Question

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Design Pattern for Undo Engine

In general, how do you deal with supporting an "undo" feature in your application? I have worked on web apps and desktop apps alike, and I have never really felt comfortable with any "undo" system I've made.

Answer 1

I believe it should be Command design pattern.

Here is article about multilevel Undo/Redo with Command pattern.

EDIT: Here is second about multilevel Undo/Redo with Memento pattern.

So probably it can be done with both.

Answer 2

Check out the Memento Pattern

Answer 3

I'd vote in favor of Command pattern over Memento. Memento pattern would be much costlier then Command patterns for Undo/Redo functionality.

Capturing and Restoring object state will be quite an expensive affair compared to just doing or undoing an action on any compatible object.