Temporal composability
- 1. Temporal Composability Undo / Redo in angular with promises and the command pattern Image by Gossins: Flow of Time
- 2. Undo / Redo Native apps (including browser) support undo Web apps and Mobile apps do not Power users produce more errors than consumers Power users on a computer with native app What happens when a power user uses a web app?
- 3. Power User
- 4. Use Case I want to be able to build a collection I want to be able to undo a price change without having to remember which price I destroyed.
- 5. Sets all items to 222% margin
- 7. invertable x f(x) f-1(f(x))
- 8. State Machine Dual Transitions
- 10. Double Stack
- 11. Double Stack asdf
- 12. Discontinuity Creating a collection ID is returned asynchronously as a promise ID not specified until after creation but needed for deletion
- 13. Promises and double closure *Each function has the result of its inverse as input msg Results Promise Context Arguments Function Results Promise inverse msg
- 14. Promises
- 15. Reusablility & Composiblity F -> $q(f) - Function that generates a promise (reuse allows for unlimited undo/redo) Asynchronous actions are handled (composition) Anything can undo/redo if providing 2 functions User messaging for current state of undo/redo