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Couchbase Talk

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Mike Hagedorn
Mike Hagedorn

This document provides an overview of building mobile applications with Couchbase. It introduces Couchbase Lite, an embedded JSON database that can work locally or sync with Couchbase Server. It describes how to initialize Couchbase Lite, create and query documents and views, customize table cells, add and delete items, and set up continuous replications between devices and a remote server. The document also demonstrates how to model objects with the CBLModel class to map to Couchbase documents. Sample code is provided and two demo apps are referenced that showcase Couchbase across iOS and OSX platforms syncing to a shared database.

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Writing Mobile Applications with Couchbase Knoxville Cocoaheads March 2016
Who is this guy? • Mike Hagedorn • Language Polyglot
Why Couchbase? Changing face of IT Demands HA Scalable Agile, Schemaless CB: Synching, Admin GUI, SDKs
Couchbase History
Couchbase Terms • Node • Cluster • Bucket • Document • View
Couchbase Components Mobile embedded local db with sync Gw internet facing component Server: Ent grade nosql db
Couchbase Server
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!
Sync Gateway CBL Device 1 CBL Device 2 CB Server Cluster 1 Data Needed Here! ? Remote Data Center SGW
Couchbase Model • An object oriented wrapper on top of CBLDocument • Somewhat like NSManagedObject
Couchbase Challenges • Complicated Queries are Hard • Views!
Getting Started • DL Couchbase Lite Framework • Add CouchbaseLite.framework to your project • There is no step 3
Initialization //AppDelegate CBLManager *manager = [CBLManager sharedInstance]; NSError *error; self.database = [manager databaseNamed:kDBName error: &error]; if (error) { NSLog(@"error getting database %@",error); exit(-1); }
Database Rockets Name Weight Diameter Cd alpha 29 25 0.75 hawk 35 30 0.8
Document { "coefficientFriction": 0.75, "diameter": 25, "name": "alpha110", "type": "rocket", "weight": 23 } # Bb6YvfoCH7NIgsVDtgjE7O Unique ID May contain binary attachments
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"]; } Map/Reduce Called on every document Optional Reduce
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;
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 }
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… }
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"); }
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]; } }
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];
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
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) };
Demo • https://github.com/mwhagedorn/ couchbase_ios_rockettown • https://github.com/mwhagedorn/ couchbase_osx_rockettown • Two platforms synching to one database
Questions? • @mwhagedorn

More Related Content

Couchbase Talk

  • 2. Who is this guy? • Mike Hagedorn • Language Polyglot
  • 3. Why Couchbase? Changing face of IT Demands HA Scalable Agile, Schemaless CB: Synching, Admin GUI, SDKs
  • 5. Couchbase Terms • Node • Cluster • Bucket • Document • View
  • 6. Couchbase Components Mobile embedded local db with sync Gw internet facing component Server: Ent grade nosql db
  • 8. 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!
  • 9. Sync Gateway CBL Device 1 CBL Device 2 CB Server Cluster 1 Data Needed Here! ? Remote Data Center SGW
  • 10. Couchbase Model • An object oriented wrapper on top of CBLDocument • Somewhat like NSManagedObject
  • 11. Couchbase Challenges • Complicated Queries are Hard • Views!
  • 12. Getting Started • DL Couchbase Lite Framework • Add CouchbaseLite.framework to your project • There is no step 3
  • 13. Initialization //AppDelegate CBLManager *manager = [CBLManager sharedInstance]; NSError *error; self.database = [manager databaseNamed:kDBName error: &error]; if (error) { NSLog(@"error getting database %@",error); exit(-1); }
  • 14. Database Rockets Name Weight Diameter Cd alpha 29 25 0.75 hawk 35 30 0.8
  • 15. Document { "coefficientFriction": 0.75, "diameter": 25, "name": "alpha110", "type": "rocket", "weight": 23 } # Bb6YvfoCH7NIgsVDtgjE7O Unique ID May contain binary attachments
  • 16. 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"]; } Map/Reduce Called on every document Optional Reduce
  • 17. 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;
  • 18. 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 }
  • 19. 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… }
  • 20. 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"); }
  • 21. 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]; } }
  • 22. 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];
  • 23. 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
  • 24. 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) };