by Ihor Vasylyk

1. CouchDB/PouchDB
approach for hybrid
mobile applications
Ihor Vlasyuk, SoftServe

2. Who I am?
Technical Lead at SoftServe.
Involved to mobile development.

3. Agenda
● Modern solution architecture overview
● Typical Problems
● Quick solutions overview
● PouchDB/CouchDB concept
● QA

4. Typical Modern Solution

5. Let’s Digg

6. What we have?
● Server side API code
● Frontend code
● Native mobile code
● Database code

7. What With Mobile Code?

8. What With Developers?

9. What Are Results?
● Lot of platform specific code
● Problem with synchronization
● Lot of peoples involved to project
● Lot of different technologies used

10. And What to Do?

11. And What to Do?
Don’t ask me I don’t know. No Pain No Gain.

12. Let’s think together
● We need to minimize number of
technologies used on project
● Nice to have one code base

13. Cross Platform Solutions

14. Let’s Holy War begin

15. Quick Overview

16. Quick Overview
● Native applications
● Web based applications
● Hybrid applications

17. Native Applications
Pros
● Offers best user experience to build
complex, reach and responsive applications
that offer the best performance
● Has access to all native features provided
by platform

18. Native Applications
Cons
● Its typically device and platform specific
● Requires installation, upgrading and
uninstallation
● Distribution of the application is more
cumbersome and it’s often depended from
AppleStore, Android market etc.

19. Web Based Applications
Pros
● Reuses existing web applications
● Minor tweaks to CSS and HTML are enough
to change UI experience
● No installation, upgrade, uninstall
● HTML5 can take advantage some native
features like geolocation, local storage etc.

20. Web Based Applications
Cons
● Even with HTML5, access to native features
is very limited
● Difficult to implement application that will
work in disconnected state
● Performance and usability is not as good as
native applications

21. Hybrid Applications
Hybrid applications are built by combining
native components and web components. Web
components are built using HTML, CSS, and
JavaScript and wrapped by a native container
(internal browser) that not only displays them
but also gives them access to native
functionality through JavaScript.

22. Hybrid Applications
Pros
● Existing web assets can be used.
● Access to all native features.
● Can provide a rich user experience by using
native components intelligently

23. Hybrid Applications
Cons
● Accessing native functionality using
JavaScript comes with a certain overhead
and is not as efficient as a native app.
● UI with HTML5 and CSS still not so
responsive as native

24. No Silver Bullet

25. So we went with Cordova

26. Stop! And What With This?
● Lot of platform specific code
● Problem with synchronization
● Lot of peoples involved to project
● Lot of different technologies used

27. Aha Unresolved Problem
● Lot of platform specific code
● Problem with synchronization
● Lot of peoples involved to project
● Lot of different technologies used

28. Welcome CouchDB

29. What is CouchDB?
CouchDB is one of what many are calling
NoSQL solutions. Specifically, CouchDB is a
document-oriented database and within each
document fields are stored as key-value maps.
Fields can be either a simple key/value pair,
list, or map.

30. What is CouchDB?
CouchDB offers us these features:
● Easy replication of a database across
multiple server instances
● REST-like interface for document insertion,
updates, retrieval and deletion
● JSON-based document format (easily
translatable across different languages)

31. Sync Problem

32. Sync Problem

33. Sync Problem

34. Welcome PouchDB

35. WTF?
You Said that we are trying to decrease
number of technologies used in solution?

36. What is PouchDB?
PouchDB is a JavaScript implementation of
CouchDB. Its goal is to emulate the CouchDB
API with near-perfect fidelity, while running in
the browser or in Node.js.

37. What is PouchDB?
PouchDB and CouchDB were designed for one
main purpose: sync. Jason Smith has a great
quote about this:
The way I like to think about CouchDB is this: CouchDB is
bad at everything, except syncing. And it turns out that's
the most important feature you could ever ask for, for
many types of software."

38. PouchDB concept

39. With PouchDB

40. CouchDB, PouchDB and Cordova

41. Setup
<script src="pouchdb-3.5.0.min.js"></script>

42. Synchronization

43. Conflicts

44. Messaging (pub/sub)

45. Questions?