Clojurescript, Om and the future of the SPA
How did I get here?
The Guardian
The Guardian is...
- shockingly...
The Guardian is...
- shockingly...
- hiring!
The Guardian is...
- shockingly...
- hiring!
http://developers.theguardian.com
Clojure Exchange talk
- Use Wisp to get macros and better functions
- Use Mori to get great data structures
- Ship the result via NPM modules
No code
No demos
All talk
OM
David Nolan
React
Immutablity
CSP
Improve your SPA performance with this one weird trick
How do we render our content?
When should we render our content?
How should we model our app?
The takeaway
- State should be singular and atomic
- Rendering should be deferred until necessary and avoid access mutable low-level APIs
- Events should be abstracted to a higher-level and only the abstraction should be used in code
Making it happen
They told me I had to use Clojure
And I said...
- No
- No
- No
But I already know Javascript!
And Attwood's Law
Javascript
How much does syntax matter?
Languages
- Javascript
- Clojurescript
- Elm
- Purescript
Dialects
- Typescript
- Coffeescript/LiveScript
- ES6/7
Web
Assembly
Does anyone read source code now?
"I installed it via NPM"
Re-implementing all the things in Javascript
Pros & Cons
The three pillars
- Immutable data
- Event streams
- DOM rendering
Immutable
data
Immutable data and React
Lee Byron
Mori versus ImmutableJS
We need immutable data
- To reason about code
- To simplify scope
- And equality
- To reduce bugs
- And make us think about state transistions
There is no sensible reason to not use ImmutableJS
Event
handling
Why can't we just get by with events?
"Functional reactive programming"
"Reactive programming"
Why event buses don't work
- Queues
- Bounded
- Unbounded
CSP
Communicating Sequential Processes
Clojurescript or ES6 (js-csp)
The evolution of events
- Callbacks
- Listeners
- Observables
- Event streams
The trouble with observables
- Complex stream combinations (RxMarbles)
- Require care to separate reading from writing
- No access to events before subscribing
- Stateful and complex
Implementations
- RxJS
- Bacon/Kefir
- One hundred homebrews
- es-observable
No recommendations
Rendering
HTML
What's wrong with React?
- Component model
- Difference computations
- Doesn't use templating
- Mutable by default
- Unopinionated about state
The Reactive Loop
Sébastien Cevey
http://slides.com/theefer/reactive-loop-jscamp#/
Model
Events
View
Intents
To Virtual-Dom or not
FFS... yes
Frameworks that dom-diff
- RiotJS
- Deku
- Ractive
- Omniscient
- Mithril
- Mercury
- Cycle
Frameworks that dom-diff and integrate immutable data
- Omniscient
Frameworks that dom-diff and integrate immutable data and use lightweight vdom rendering
- Well...
Final thoughts
What can browsers and standards do for us?
- New DOM APIs
- Immutable data structures in ES
What can we do for ourselves?
- Get behind native observables
- Develop a habit of const
- Use immutable data
The three pillars
- Immutable data
- Unidirectional event streams
- Data-driven atomic model rendering
Thank you!
- Twitter/Github: rrees
- Blog: rrees.me
Clojurescript, Om and the future of the SPA
By Robert Rees
Clojurescript, Om and the future of the SPA
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