Dumb and smart components + redux (1)
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The document discusses refactoring Angular applications to use components instead of controllers and templates. It recommends building applications as trees of reusable components, with each component containing related HTML, JavaScript, and CSS. Dumb components focus on visualization, while smart components handle data fetching and state management. The document then introduces Flux architecture and Redux for managing state in a predictable, centralized way using immutable data and reducer functions. Components interact by dispatching actions that update the single source of truth Redux store.
Dumb and smart components + redux (1)
- 1. Dumb and smart components & redux Brecht Billiet
- 2. About me Brecht Billiet Frontend Architect - Coach - Trainer http://brecht.io @brechtbilliet
- 3. Who still uses ng- controller and ng- include?
- 4. Doesn’t that bother you? ● What HTML belongs to what JS? ● Where do the templates live? ● Absolute template-paths are not maintainable ● What logic belongs in a controller or directive? ● This template should contain... oh wait, there is an ng-include there. ● How do you pass data to your controllers?
- 5. Think in components... ● 1 piece HTML + 1 piece LOGIC = COMPONENT ● You know it as: element directives ● Custom DOM tags ● A component has a single responsability ● We could use webcomponents + shadow DOM ● Sandboxed work ● Note: angular 1.5 has new component syntax
- 6. What should you refactor to components?
- 8. Everything is a component ● Your application is a tree of components ● Your pages are components ● Even your application is a component
- 9. application Html + js + css html + js + css html + js + css html + js + css html + js + css html + js + css html + js + css html + js + css html + js + css html + js + css html + js + css
- 10. application Html + js + css fooPage html + js + css html + js + css barPage html + js + css html + js + css html + js + css html + js + css html + js + css html + js + css Routingconfig: template: ‘<foo-page/>’ Routingconfig: template: ‘<bar-page/>’
- 11. Easier to debug
- 12. Other advantages ● No scope soup ● Nice hierarchy view ● Single responsability ● No more absolute paths ● Easier to reason about ● Easier to refactor ● Easier to upgrade to ng2
- 13. What about attribute-directives? ● Let’s call them behaviors from now ● They add some logic to existing or custom components ● Separate them from your components folder
- 14. DEMO
- 17. Any rules of thumb?
- 20. Keep them dumb where possible...
- 21. Dumb component Smart component (container) Doesn’t know about the application Knows about the application Doesn’t do data fetching Does data fetching Main purpose is visualization Interacts the application Reusable Not reusable Only communicates with its direct parent Passes state and data to its children Doesn’t do state management Does state management
- 24. State management ● State is very hard to manage in SPA’s ● State can be ○ data: results from REST calls ○ “sidebar is collapsed” or “spinner is active” ○ Which tab is currently active
- 25. State management ● 3 types of state ○ Data state ○ Application state ○ Inner state (e.g value of textbox) We don’t have to persist nor manage that
- 26. Why is it so hard to manage? ● 1-way databinding and 2-way databinding ● javascript references that are being broken and sometimes kept ● We can mutate the data in a million different ways ● No structure ● Data flows in different directions
- 27. application state & logic state & logic state & logic state & logic state & logic state & logic state & logic state & logic state & logic state & logic Without flux
- 28. 1 2 5 6 3 7 8 4 9 10 11 Without flux
- 29. 1 2 5 6 3 7 8 4 9 10 11 I changed Without flux
- 30. 1 2 5 6 3 7 8 4 9 10 11 I changed So did I Without flux
- 31. 1 2 5 6 3 7 8 4 9 10 11 I changed So did I My changes should reflect 6 and 4 Without flux
- 32. 1 2 5 6 3 7 8 4 9 10 11 I changed So did I My changes should reflect 6 and 4 I have to subscribe before 8 sends a message Without flux
- 33. 1 2 5 6 3 7 8 4 9 10 11 I changed So did I My changes should reflect 6 and 4 I have to subscribe before 8 sends a message I’m sending an event upwards Without flux
- 34. 1 2 5 6 3 7 8 4 9 10 11 I changed So did I My changes should reflect 6 and 4 I have to subscribe before 8 sends a message I’m sending an event upwards I’m sending events downwards Without flux
- 35. 1 2 5 6 3 7 8 4 9 10 11 I changed So did I My changes should reflect 6 and 4 I have to subscribe before 8 sends a message I’m sending an event upwards Without flux I’m sending events downwards
- 36. 1 2 5 6 3 7 8 4 9 10 11 I changed So did I My changes should reflect 6 and 4 I have to subscribe before 8 sends a message I’m sending an event upwards I get my data from model x and I can update it here I get my data from model z Without flux I’m sending events downwards I get my data from model y
- 37. 1 2 5 6 3 7 8 4 9 10 11 I changed So did I My changes should reflect 6 and 4 I have to subscribe before 8 sends a message I’m sending an event upwards I get my data from model x and I can update it here I get my data from model z Without flux My data is passed by twoway binding I’m sending events downwards I get my data from model y My data is passed by oneway binding My data is passed by twoway binding
- 38. Where do those states/events come from?
- 39. Who updated my state??
- 40. Who updated/notified which component?
- 42. Flux helps with that ● Brings structure in data flow ● Not a framework but an architecture by facebook ● Unidirectional dataflow, oneway databinding ● Data flows from the top down ● Easier to reason about state
- 43. ● Action ○ Has an action type and a payload ● Dispatcher ○ Dispatches the actions to the store ● Store ○ Contains state ● View Components
- 44. ● The unidirectional dataflow makes it easy to reason about
- 45. I use Redux! Redux is based on flux, but it’s easier
- 46. Redux ● Written by Dan Abramov (Facebook) ● Easier to use and less bloat ● Only has one store!! ● Completely Immutable data structure ● Uses reducers (pure functions) ● Flux approves
- 47. 1 2 5 6 3 7 8 4 9 10 11 STORE
- 48. 1 2 5 6 3 7 8 4 9 10 11 Me too Me too Me too Me too STORE I only send actions upwards to the store I’m the single- source-of-truth in your application!! ;-)
- 49. 1 2 5 6 3 7 8 4 9 10 11 Me too Me too I’m dumb I’m dumb I’m dumb I’m dumb I’m dumb I’m dumb STORE Me too I only send actions upwards to the store Me too I’m the single- source-of-truth in your application!! ;-) Dumb components only notify their direct parents! No state management needed here :-)
- 50. What’s different? ● We have one single source of truth: the store ● We don’t update state ourselves anymore, the store handles all the state of our application ● State is immutable ● Actions are always sent upwards
- 51. What’s different? ● Dumb components don’t do state management ● State is being updated by pure functions (reducers) ● When the store is updated it notifies all the smart components
- 53. Actions ● Actions have a type and a payload ● Keep the types together, gives clear overview
- 54. Actions
- 55. Reducers ● Pure functions ● reducer(state: MyState, action: Action): MyState ● they update the state ● Completely immutable
- 56. Reducers
- 58. Middleware ● Easy logging, debugging ● Reproducible action state (pushable to server) ● Timetraveling with redux-devtools (requires react to be bundled in the angular project)
- 59. Check it out ● egghead.io course (Free) ○ https://egghead.io/series/getting-started-with-redux
- 60. Special thanks to ● Kwinten Pisman (@kwintenp) ● Jurgen Van de Moere (@jvandemo)
- 61. Questions?
- 62. One more thing Angular2, rxjs, redux, @ngrx/store, Typescript, webpack http://workshop.brecht.io @brechtbilliet Workshop June 2016
- 63. Thank you!