App Data, Everywhere: Cross-Device Content Sharing

We live in a cross-platform world, with users now expecting the data they create to follow them across various devices, browsers and even offline. Consumers’ data sync demands range from simple needs (i.e. accessing the most up-to-date documents anywhere) to more complicated scenarios (such as picking up a game right where it was left off on another device). As user demand for easy access to content from any device grows, managing data has moved from a pure storage problem to one of data synchronization.

SXSW, March 9, 2014
http://schedule.sxsw.com/2014/events/event_IAP23904

Transcript

1. App Data, Everywhere Leah Culver, Dropbox SXSW 2014
2. Dropbox “Your [digital] stuff everywhere”
3. Wherever you are
4. Safe and secure
5. Share with friends
6. • Filesystem that just works • “The magic folder” Then
7. • Multi-device world • Apps • Mobile storage and sync Now
8. • Cross-platform support • Store data • User auth and permissions • Sync across devices • Offline access Mobile backend challenges
9. Write your own backend API Solution
10. Mobile backend service
 (Parse, iCloud, Dropbox, etc.) Solution
11. Dropbox for your mobile apps
12. Store data in user’s own Dropbox • Free for developers • Access to files outside your app • User owns their data
13. How can I use Dropbox in my app?
14. Core API • REST-ish, OAuth 2.0, JSON • Android, iOS, OS X, Python, Ruby, Java, PHP • Community-supported libraries for C#, JavaScript, Perl, etc. HTTP API for files
15. • List files
 /metadata/<root>/<path> • Upload file
 /files_put/<root>/<path> • Get a thumbnail
 /thumbnails/<root>/<path> • Share via a link
 /shares/<root>/<path> Core API
16. Authentication and permissions • Connect with Dropbox • Full or limited access • Only request permissions that
 your app needs
17. Permissions
18. Permissions App folder
 Permission to a specific folder ! File types
 Permission to a class of files (e.g. images) ! Full Dropbox
 Permission to everything
19. Core API is great. So what now?
20. Sync across devices • Files available everywhere • Syncs across devices • Offline access
21. Sync API
22. Sync API (like Core API) • Files for your app in your user’s Dropbox • Store and sync photos, videos, files, etc.
23. • Handles offline caching and syncing • Notifications of changes Sync API
24. Image Grid Sample
26. Image Grid Sample code iOS
27. Initialize the filesystem
28. Listen for changes
29. Display thumbnail
30. Great for files… but what about data?
31. Sync API file system-like interface Datastore API structured data Mobile APIs
32. Bundled together for Android, iOS, OS X
33. Datastore API • Storage for structured data • Like a NoSQL database • Stored in the user’s Dropbox • Not files!
34. account→datastore→table→record→field→value Datastore API
35. Why not files? Monolithic → inefficient syncing Opaque → conflicts
36. Why not files? • Clearly defined structure • More efficient syncing • Advanced conflict resolution
37. Similar to Sync API … • Handles offline caching and syncing • Notifications of changes
38. Click the Box
40. Click the Box code JavaScript
41. Initialize datastore
42. Click listener
43. Listen for changes
44. Display level
45. Take it offline!
47. • Local changes cached when offline • Syncs changes with server when online • Automatically merge changes Offline / online syncing
48. • List of changes - “delta” • Client sends delta with “parent revision” on sync • Server rejects a delta if parent revision doesn’t match • Server sends list of deltas to catch up • Client resolves conflict, sends new delta Conflict resolution
49. Device A Server Device B Visually 2 r: 2 2 r: 2 2 r: 2
50. Device A Server Device B Visually 2 r: 2 2 r: 2 2 r: 2 2 r: 2 2 r: 2 3 r: 2
51. Device A Server Device B Visually 2 r: 2 2 r: 2 2 r: 2 3 r: 3 3 r: 3 2 r: 2 2 r: 2 3 r: 2
52. Device A Server Device B Visually 2 r: 2 2 r: 2 2 r: 2 3 r: 3 3 r: 3 2 r: 2 2 r: 2 3 r: 2 4 r: 2
53. Device A Server Device B Visually 2 r: 2 2 r: 2 2 r: 2 3 r: 3 3 r: 3 2 r: 2 2 r: 2 3 r: 2 4 r: 2 3 r: 3 3 r: 3 4 r: 2
54. Device A Server Device B Visually 2 r: 2 2 r: 2 2 r: 2 3 r: 3 3 r: 3 2 r: 2 2 r: 2 3 r: 2 4 r: 2 3 r: 3 3 r: 3 4 r: 2 3 r: 3 3 r: 3 * r: 2
55. Device A Server Device B Visually 2 r: 2 2 r: 2 2 r: 2 3 r: 3 3 r: 3 2 r: 2 2 r: 2 3 r: 2 4 r: 2 3 r: 3 3 r: 3 4 r: 2 3 r: 3 3 r: 3 * r: 2 * Client resolves to new delta
56. Device A Server Device B Visually 2 r: 2 2 r: 2 2 r: 2 3 r: 3 3 r: 3 2 r: 2 2 r: 2 3 r: 2 4 r: 2 3 r: 3 3 r: 3 4 r: 2 3 r: 3 3 r: 3 * r: 2 * Client resolves to new delta 3 r: 3 3 r: 3 4 r: 3
57. Device A Server Device B Visually 2 r: 2 2 r: 2 2 r: 2 3 r: 3 3 r: 3 2 r: 2 2 r: 2 3 r: 2 4 r: 2 3 r: 3 3 r: 3 4 r: 2 3 r: 3 3 r: 3 * r: 2 * Client resolves to new delta 3 r: 3 3 r: 3 4 r: 3 4 r: 4 3 r: 3 4 r: 4
58. Device A Server Device B Visually 2 r: 2 2 r: 2 2 r: 2 3 r: 3 3 r: 3 2 r: 2 2 r: 2 3 r: 2 4 r: 2 3 r: 3 3 r: 3 4 r: 2 3 r: 3 3 r: 3 * r: 2 * Client resolves to new delta 3 r: 3 3 r: 3 4 r: 3 4 r: 4 3 r: 3 4 r: 4 4 r: 4 4 r: 4 4 r: 4
59. • Server rejects delta • Server sends delta to catch up • Client resolves conflict • Client sends new delta • Server accepts new delta Conflict resolution
60. • Changes to different records commute • Deletions win • Changes to the same field are merged Conflict resolution rules
61. Customizable per-field: • Remote (default) - server wins • Local - client wins • Max - greater value wins • Min - lesser value wins • Sum - adds differences together Conflict resolution
62. Custom resolution rule
63. Powerful stuff…
64. • Cross-platform SDKs • Both files and data • Users’ own Dropbox • Handles offline access, sync, and conflict resolution Sync and Datastore APIs
65. Questions? dropbox.com/developers leah@dropbox.com
66. Photos http://www.flickr.com/photos/kky/704056791/ http://www.flickr.com/photos/ianmalcm/3829590116/ http://www.flickr.com/photos/doug88888/3130802503/ http://www.flickr.com/photos/eulothg/5906431611/ http://www.flickr.com/photos/tambako/2844515466/ http://www.flickr.com/photos/7447470@N06/2059257387/ http://www.flickr.com/photos/billy_wilson/4123838868/ http://www.flickr.com/photos/yourdon/10018150113/ http://www.flickr.com/photos/mager/2659619029/ http://www.flickr.com/photos/ben_grey/4582294721/ http://www.flickr.com/photos/adactio/12674602864/ http://www.flickr.com/photos/mako_side_b/2332323845/ http://www.flickr.com/photos/coofdy/11492948263/ http://www.flickr.com/photos/arts/42217172/ http://www.flickr.com/photos/drachmann/327122302/ http://www.flickr.com/photos/evergreenkamal/395448039/ http://www.flickr.com/photos/aliaholle/5888906660/ http://www.flickr.com/photos/vinothchandar/5148046888/