The proliferation of mobile devices and the Internet of Things has created a new set of requirements for todays IT infrastructure. Scalability and the need to adapt to rapidly changing data requirements have popularized a wave of NoSQL backend datastores. Typically though, this kind of datastore has been difficult to use with mobile devices. In this talk I want to present Couchbase as a solution to many mobile NoSQL problems. It provides disconnected and connected operation, high scalability and all the flexibility that any NoSQL solution provides, and it does this without requiring the developer to write complicated synchronization code between the mobile client and the backend datastore. Couchbase and its sync gateway handles all of this for you leaving you to focus on your business logic. In addition, this power can be leveraged across Android, Windows, Linux and others. I will present a short intro on the power and scalability of document databases and then show a demo of a set of different clients all talking to the same backend and demonstrate the near realtime updates possible. Have you had trouble understanding complex datastores such as CoreData? Then this talk is for you. Its all about getting stuff done in a straightforward, performant and yes cross platform way. Stop pounding rocks together and get stuff done!

1. Writing Mobile
Applications with
Couchbase
CodeStock 2016
July 2016

2. Who is this guy?
• Mike Hagedorn
• Language Polyglot
• Knoxville, TN
• @mwhagedorn
• http://spkr8.com/s/16930

3. The Plan
• Relational Datastores
• NoSQL Datastores
• Couchbase Components
• How To Get Started
• Demo

4. – J.K. Rowling
“There's always room for a story that can
transport people to another place.”

5. April 1970

6. April 1970
what year JFK/Rice Sept 1962

7. April 1970

8. Oxygen Tanks
Houston, we’ve had a problem
65 28 5

9. – Madeleine L’Engle
“Nothing important is completely explicable.”

10. Data Stores

11. Relational Data Stores
also created in 1970, E.F. Codd IBM

12. Relational Example

13. Why NoSQL?
Changing face of IT Demands
next 20 yrs 40-50% more data, 95% of
that will be non structured
BMW/cars as nodes

14. Couchbase History

15. Couchbase Terms
• Node
• Cluster
• Bucket
• Document
• View

16. Couchbase Components
Mobile embedded local db with sync
Gw internet facing component
Server: Ent grade nosql db

17. Couchbase Server

18. Couchbase Lite
Couchbase Lite is an embedded JSON database
that can work standalone, in a P2P network, or as a
remote endpoint for Couchbase Server.
Embedded
All IO is local
Syncs are transparent in background
Disconnected operation
NO PUSH
NO Network
CBL
Device 1
CBL
Device 2
CB
Server
Cluster 1
with
GW!

19. Sync Gateway
CBL
Device 1
CBL
Device 2
CB
Server
Cluster 1
Data
Needed
Here!
?
Remote Data Center
SGW

20. Couchbase Model
• An object oriented wrapper on top of
CBLDocument
• Somewhat like NSManagedObject
• IOS/OSX only

21. Couchbase Views
views process the unstructured data to
produce an index
live queries

22. Couchbase Challenges
• Complicated Queries are Hard
• Views!
• Lack of a standard Query Language
show a view javascript

23. Couchbase Challenges
• Complicated Queries are Hard
• Views!
• Lack of a standard Query Language
show a view javascript

24. N1QL
possible to use from the

25. Getting Started
• DL Couchbase Lite Framework
• Add CouchbaseLite.framework to your project
• There is no step 3

26. Initialization
//AppDelegate
CBLManager *manager = [CBLManager sharedInstance];
NSError *error;
self.database = [manager databaseNamed:kDBName error: &error];
if (error) {
NSLog(@"error getting database %@",error);
exit(-1);
}

27. Database
Rockets
Name Weight Diameter Cd
alpha 29 25 0.75
hawk 35 30 0.8
a collection of records

28. Document
{
"coefficientFriction": 0.75,
"diameter": 25,
"name": "alpha110",
"type": "rocket",
"weight": 23
}
# Bb6YvfoCH7NIgsVDtgjE7O
Unique ID
May contain binary attachments
typeless, convention:type

29. Database View
//RootController or CBModel
//Define a view that only returns documents of type ‘kRocketDocType’
CBLView* view = [db viewNamed: @"rockets"];
if (!view.mapBlock) {
// Register the map function, the first time we access the view:
[view setMapBlock: MAPBLOCK({
if ([doc[@"type"] isEqualToString:kRocketDocType])
emit(doc[@"name"], nil);
}) reduceBlock: nil version: @"1"];
}
function (doc,meta) {
if(doc.type == “rocket”){
emit(doc.name,null);
}
}
Map/Reduce
Called on every document
Optional Reduce
not replicated to server

30. Using Views in your UI
// Create a query showing rockets:
CBLLiveQuery* query = [[[database viewNamed:@"rockets"] query]
asLiveQuery];
// Plug the query into the CBLUITableSource, which will use it to drive
the table.
// (The CBLUITableSource uses KVO to observe the query's .rows
self.dataSource.query = query;
self.dataSource.labelProperty = @"name";
// Assumes something like this in your controller
@property (nonatomic) IBOutlet UITableView* tableView;
@property (nonatomic) IBOutlet CBLUITableSource* dataSource;

31. Using Views in your UI
// Create a query showing rockets:
CBLLiveQuery* query = [[[database viewNamed:@"rockets"] query]
asLiveQuery];
// Plug the query into the CBLUITableSource, which will use it to drive
the table.
// (The CBLUITableSource uses KVO to observe the query's .rows
self.dataSource.query = query;
self.dataSource.labelProperty = @"name";
// Assumes something like this in your controller
@property (nonatomic) IBOutlet UITableView* tableView;
@property (nonatomic) IBOutlet CBLUITableSource* dataSource;

32. Using Views in your UI
// Create a query showing rockets:
CBLLiveQuery* query = [[[database viewNamed:@"rockets"] query]
asLiveQuery];
// Plug the query into the CBLUITableSource, which will use it to drive
the table.
// (The CBLUITableSource uses KVO to observe the query's .rows
self.dataSource.query = query;
self.dataSource.labelProperty = @"name";
// Assumes something like this in your controller
@property (nonatomic) IBOutlet UITableView* tableView;
@property (nonatomic) IBOutlet CBLUITableSource* dataSource;

33. Customizing Table Cells
- (void)couchTableSource:(CBLUITableSource*)source
willUseCell:(UITableViewCell*)cell
forRow:(CBLQueryRow*)row
// Set the cell background and font:
// Configure the cell contents. Map function (above) copies the doc
properties into its value, so we can read them without having to load the
document.
NSDictionary* rowValue = row.value;
BOOL checked = [rowValue[@"check"] boolValue];
if (checked) {
cell.textLabel.textColor = [UIColor grayColor];
cell.imageView.image = [UIImage imageNamed:@"checked"];
} else {
cell.textLabel.textColor = [UIColor blackColor];
cell.imageView.image = [UIImage imageNamed: @"unchecked"];
}
// cell.textLabel.text is already set, thanks to setting up labelProperty
}

34. Selecting A Row
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath
*)indexPath
{
NSLog(@"didSelectRowAtIndexPath");
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
CBLQueryRow *row = [self.dataSource rowAtIndex:indexPath.row];
ASDRocket* rocket = [ASDRocket modelForDocument: row.document];
// Do something with rocket…
}

35. Selecting A Row
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath
*)indexPath
{
NSLog(@"didSelectRowAtIndexPath");
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
CBLQueryRow *row = [self.dataSource rowAtIndex:indexPath.row];
ASDRocket* rocket = [ASDRocket modelForDocument: row.document];
// Do something with rocket…
}

36. Adding Items
- (IBAction) insertNewObject: (id)sender {
ASDRocket* rocket = [ASDRocket modelForNewDocumentInDatabase:self.database];
rocket.name=name;
rocket.weight = 23.0;
NSError* error;
if (![rocket save: &error]) {
return nil;
}
NSLog(@"Rocket Created");
}

37. Adding Items
- (IBAction) insertNewObject: (id)sender {
ASDRocket* rocket = [ASDRocket modelForNewDocumentInDatabase:self.database];
rocket.name=name;
rocket.weight = 23.0;
NSError* error;
if (![rocket save: &error]) {
return nil;
}
NSLog(@"Rocket Created");
}

38. Deleting Items
-(void) tableView:(UITableView*)tableView
commitEditingStyle:(UITableViewCellEditingStyle)editingStyle
forRowAtIndexPath:(NSIndexPath *)indexPath{
if (editingStyle == UITableViewCellEditingStyleDelete){
CBLQueryRow *row = [self.dataSource rowAtIndex:indexPath.row];
ASDRocket* rocket = [ASDRocket modelForDocument: row.document];
NSError* error;
if (![rocket deleteDocument: &error]){
NSLog(@"Unable to delete Rocket");
return;
}
[self.tableView reloadData];
}
}

39. Replications
CBLReplication *pull;
CBLReplication *push;
h;
pull = [_database createPullReplication:_remoteURL];
pull.continuous = YES;
pull.network = @"WiFi";
push = [_database createPushReplication:_remoteURL];
push.continuous = YES;
pull.network = @"WiFi";
[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(replicationProgress:)
name:kCBLReplicationChangeNotification
push];
[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(replicationProgress:)
name:kCBLReplicationChangeNotification
pull];

40. CBLModel
• Maps Objects to documents
@interface ASDRocket : CBLModel
+ (NSString*) docType;
@property (strong) NSString *name;
@property (assign) double diameter;
@property (assign) double weight;
@property (assign) double coefficientFriction;
/** Returns a query for all the rockets in a database. */
+ (CBLQuery*) queryRocketsInDatabase: (CBLDatabase*)db;
/** Returns a query for all the rockets with name in a database */
+ (CBLQuery*) findInDatabase:(CBLDatabase*)db byName:(NSString *)name;
@end

41. CBLModel
• No types in documents
• convention is to use type field
• Map functions can pick out docs with the right type
if (doc.type == “rocket”){
emit(doc.created, doc.text)
};

42. Summarywe’ve seen
why no sql matters, and is needed
shown how couch base can enable
difficult distributed computing
next a demo….

43. So What Happened
5 yrs earlier
28V components spec to also 65
Missed the memo

44. Demo
• https://github.com/mwhagedorn/
couchbase_ios_rockettown
• https://github.com/mwhagedorn/
couchbase_osx_rockettown
• Two platforms synching to one database

45. Questions?
• @mwhagedorn
• http://spkr8.com/s/16930
• https://github.com/mwhagedorn/
couchbase_ios_rockettown
• https://github.com/mwhagedorn/
couchbase_osx_rockettown