The document discusses the advantages of using Om with ClojureScript for functional frontend engineering, emphasizing simplicity and performance, particularly with the implementation of an undo feature. It highlights key elements of the ClojureScript ecosystem, including macros and persistent data structures as significant benefits. Additionally, various references and resources for further exploration of the topics are provided.

1. OM
@TAKUFUKUSHIMA

3. OM ADDS MORE VALUES
TO REACT.JS

4. OM SWEET OM: (HIGH-)FUNCTIONAL
FRONTEND ENGINEERING WITH
CLOJURESCRIPT AND REACT

5. CONCLUSION:
SIMPLICITY WINS

7. PERFORMANCE

9. UNDO
THE BIGGEST
DIFFERENTIATOR OF OM

10. WHO DOES NEED UNDO
ON THE CLIENT-SIDE?

12. SHIFT TO THE WEB
TECHNOLOGIES

16. UNDO MADE
EASY

18. ClojureScript was a big enabler.
— David Nolen, Creator of Om

19. TIME TRAVEL
;; Initial state.
(def app-history (atom [@app-state]))
;; When the state is changed, it's added to the history.
(add-watch app-state :history
(fn [_ _ _ n]
(when-not (= (last @app-history) n)
(swap! app-history conj n))
(set! (.-innerHTML (.getElementById js/document "message"))
(let [c (count @app-history)]
(str c " Saved " (pluralize c "State"))))))
;; If the undo button is pressed, pop the state.
(aset js/window "undo"
(fn [e]
(when (> (count @app-history) 1)
(swap! app-history pop)
(reset! app-state (last @app-history)))))

20. CLOJURESCRIPT ROCKS
1. ClojureScript ecosystem
2. Macros
3. Persistent data structures

21. 1. CLOJURESCRIPT
ECOSYSTEM

22. GOOD PARTS OF CLOJURESCRIPT
▸ Clojure
▸ 3rd party libraries
▸ Source Map
▸ Interop with JavaScript

23. 2. MACROS

24. MACRO SAVES YOUR TIME
COMPILATION TIME META PROGRAMMING,
WHICH IS HARD IN JAVASCRIPT.
▸ prismatic/om-tools

25. 3. PERSISTENT DATA
STRUCTURES

29. PERSISTENT DATA
STRURCTURES ARE
MEMORY EFFICIENT

30. GET UNDO
NOW

31. WRAP-UP
SIMPLICITY AND UNDO

32. THE END OF
SLIDES; ANY
QUESTION?

33. REFERENCES
▸ Om sweet Om: (high-)functional frontend engineering
with ClojureScript and React - http://
blog.getprismatic.com/om-sweet-om-high-functional-
frontend-engineering-with-clojurescript-and-react/
▸ PrismaticEngineering Tweet - https://twitter.com/
PrismaticEng/status/478988034407276546
▸ Vue.js Performance Comparisons - http://vuejs.org/
perf/

34. REFERENCES
▸ IMMUTABILITY, INTERACTIVITY & JAVASCRIPT,
Balcerona Future JS: http://futurejs.org/agenda/
immutability-interactivity-javascript
▸ GoyaPixel - http://jackschaedler.github.io/goya/
▸ Time Travel, dosync - http://swannodette.github.io/
2013/12/31/time-travel/
▸ Adobe Photoshop.com - http://www.photoshop.com/

35. REFERENCES
▸ Google Docs - https://docs.google.com/
▸ Atom - https://atom.io/
▸ Git - http://git-scm.com/
Other pictures are distributed under © Taku Fukushima