CocoaHeads BNE July 2014

"The WWDC 2014 Edition", including latest news, Gabriel Huber's presentation on Multipeer Connectivity & Peter Ryder's presentation on JavaScriptCore.

Transcript

1. meetup.com/cocoaheads @cocoaheadsbne CocoaHeads Brisbane July 2014
2. Gabriel
 Multipeer Connectivity Ben
 News Peter
 JavaScriptCore
3. Thanks to our Sponsors
5. TheLocker.com
6. Ben
 News
7. +
8. vimeo.com/channels/nsconf6
10. github.com/schneiderandre/popping “… a collection of animation examples for iOS apps… created using the Facebook pop animation engine.”
11. oleb.net/blog/2014/05/scrollview-inertia-bouncing-rubberbanding
12. Using Clang Format tonyarnold.com/2014/05/31/autoformatting-your-code
14. “They put the D back in WWDC”
15. Storyboards
 App Extensions incl. Widgets, Share Extensions & Action Extensions
16. Touch ID Handoff *Kit incl. PhotoKit, HealthKit, HomeKit, CloudKit
17. 1000 Beta testers Email only no UUIDs or provisioning profiles Internal Testing
18. Live Rendering
 View Debugging Sorry, IttyBittyApps Frameworks Performance Tests
19. “a new language for the future of Apple software development”
21. Expressive, Type Safe, Fast
 Namespaces, Closures Tuples, Optionals, Enums Generics
24. Gabriel
 Multipeer Connectivity
25. Who$am$I? Gabriel(Hauber • Live&and&work&on&the&Sunshine&Coast • Independant&so6ware&developer • Wannabe&author&(fic=on) • Student&&&teacher
26. Developer • iOS:&4+&years • Java:&12+&years • Others:&Symbian/C++,&J2ME,&Ruby,&PHP,&etc • (Looking&for&new&projects) SongSheet(for(the(iPad(on(the(App(Store
27. A"li%le"boast SongSheet(highlighted(by(Apple(as( an(example(of(good(design.
28. Mul$peer(Connec$vity(Framework
29. Mul$peer(Connec$vity(vs(GameKit( networking • GKSession*deprecated*iOS*7*3*use*MCSession • GKSession*could*do*client*(browser),*server* (adver>ser)*or*both*(peer*to*peer) • MCSession*is*always*peer*to*peer
30. iOS$7$only
31. MC#Overview • Ad$hoc(peer(to(peer(networking • Bluetooth(&(WiFi((can(consist(of(both) • Peer,(service,(session,(adverAser,(browser • Maximum(of(8(connected(peers((including(self)
32. Peer • represents(a(peer(in(a(mul.peer(session • states:(not(connected,(connec.ng,(connected • assign(a(name((NSString)(7(can(be(anything;( something(meaningful(to(the(user(e.g.(device(name MCPeerID *myPeerID = [[MCPeerID alloc] initWithDisplayName:[UIDevice currentDevice].name];
33. Service'Type • used&for&discovery:&peers&connect&via&common& service&name • name&must&conform&to&the&format&of&a&Bonjour& service&type: • Must&be&1–15&characters&long • Can&contain&only&ASCII&lowercase&leCers,& numbers,&and&hyphens NSString * const kMyServiceTypeName = @"my-service-type";
34. Mul$peer(Session • needed%in%order%to%make%connec.ons • send/receive%data • delegate%is%no.fied%of%peer%state%changes%(not% connected,%connec.ng,%connected) self.localSession = [[MCSession alloc] initWithPeer:self.myPeerID securityIdentity:nil encryptionPreference:MCEncryptionNone]; self.localSession.delegate = self;
35. Adver&sing:,"Here,I,am!" self.advertiser = [[MCNearbyServiceAdvertiser alloc] initWithPeer:sessionContainer.myPeerID discoveryInfo:@{@"player.name" : self.myPlayerName} serviceType:kMyServiceName]; self.advertiser.delegate = self; [self.advertiser startAdvertisingPeer];
36. Discovery*info • dic%onary+of+key/value+pairs+that+is+available+to+ browsers • each+key/value+must+be+an+NSString • sent+via+a+Bonjour+TXT+record,+therefore: • max+255+bytes+for+each+key/value+pair+(including+ '=') • key+cannot+contain+'=' • recommended+max+400+bytes+to+fit+in+single+ Bluetooth+data+packet
37. MCNearbyServiceAdver/serDelegate - (void)advertiser:(MCNearbyServiceAdvertiser *)advertiser didReceiveInvitationFromPeer:(MCPeerID *)peerID withContext:(NSData *)context invitationHandler:(void (^)(BOOL accept, MCSession *session))invitationHandler • Use%the%peerID%and%info%parameters%to%present%a% suitable%UI • (Will%describe%how%to%accept%shortly)
38. Browsing:*"Who's*here?" self.browser = [[MCNearbyServiceBrowser alloc] initWithPeer:myPeerID serviceType:kMyServiceTypeName]; self.browser.delegate = self; [self.browser startBrowsingForPeers];
39. MCNearbyServiceBrowserDelegate - (void)browser:(MCNearbyServiceBrowser *)browser foundPeer:(MCPeerID *)peerID withDiscoveryInfo:(NSDictionary *)info - (void)browser:(MCNearbyServiceBrowser *)browser lostPeer:(MCPeerID *)peerID • use%the%peerID%and%info%parameters%to%present%a% suitable%UI
40. Invi%ng'a'peer'to'a'session MCPeerID *peerToInvite = ...; NSDictionary *contextDictionary = @{@"player.name" : self.myPlayerName}; NSData *context = [NSKeyedArchiver archivedDataWithRootObject:contextDictionary]; [self.browser invitePeer:peerToInvite toSession:self.localSession withContext:context timeout:30];
41. The$session$delegate$will$be$sent$the$ session:peer:didChangeState:$message$on$ successful$connect,$rejec7on$or$7meout
42. Accep%ng(an(invita%on // advertiser:didReceiveInvitationFromPeer:withContext:invitationHandler: // extract info NSDictionary *contextDictionary = (NSDictionary*) [NSKeyedUnarchiver unarchiveObjectWithData:context]; NSString *otherPlayerName = contextDictionary[@"player.name"]; // present UI UIActionSheet *actionSheet = [UIActionSheet SH_actionSheetWithTitle:otherPlayerName]; [actionSheet SH_addButtonWithTitle:@"Play Game" withBlock:^(NSInteger theButtonIndex) { invitationHandler(YES, [RTSSessionContainer sharedInstance].localSession); }]; [actionSheet SH_addButtonCancelWithTitle:@"Reject" withBlock:^(NSInteger theButtonIndex) { invitationHandler(NO, nil); }]; [actionSheet showInView:self.view];
43. The$session$delegate$will$be$sent$the$ session:peer:didChangeState:$message$on$ successful$connect
44. Network(topology • An$example: • A$is$adver1sing • B$&$C$are$browsing
45. First&connec+on • B#discovers#A,#sends#invita1on • A#accepts • A#and#B#are#now#connected#to#each#other
46. Second'connec(on • C#discovers#A,#sends#invita1on • A#accepts • C#is#now#connected#to#A • C"is"also"connected"to"B • Any#of#the#three#devices#can#send#messages#to#any# other#device#in#the#peer9to9peer#network
47. Demo
48. Every&peer&has&a&connec.on&to&every&other&peer
49. Sending'Data • via%MCSession%instance • send%arbitrary%data%to%one%or%more%peers%2%NSData • send%resource%/%stream%to%a%single%peer - (BOOL)sendData:toPeers:withMode:error: - (NSProgress *)sendResourceAtURL:withName:toPeer:withCompletionHandler: - (NSOutputStream *)startStreamWithName:toPeer:error:
50. MCSessionDelegate!to!receive! data // receive NSData - (void)session:didReceiveData:fromPeer: // data available at temp URL when didFinishReceiving - (void)session:didStartReceivingResourceWithName:fromPeer:withProgress: - (void)session:didFinishReceivingResourceWithName:atURL:withError: // provided an NSInputStream to read from - (void)session:didReceiveStream:withName:fromPeer:
51. Mul$tasking,Issues • stop&browsing&/&adver2sing&on&app&will&resign& ac2ve • restart&browsing&/&adver2sing&on&app&did&became& ac2ve • you&can&keep&a&session&alive&when&the&app&enters& the&background • must%kill&the&session&when&background&2me&has& expired&(will&need&to&reconnect&once&app&comes&to& the&foreground&again)
52. Browsing)&)Mul.tasking - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillResignActive:) name:UIApplicationWillResignActiveNotification object:nil]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationDidBecomeActive:) name:UIApplicationDidBecomeActiveNotification object:nil]; [self startBrowsing]; } - (void)viewWillDisappear:(BOOL)animated { [super viewWillDisappear:animated]; [[NSNotificationCenter defaultCenter] removeObserver:self]; [self stopBrowsing]; }
53. Browsing)&)Mul.tasking)(cont) - (void)applicationWillResignActive:(NSNotification *)notification { [self stopBrowsing]; } - (void)applicationDidBecomeActive:(NSNotification *)notification { [self startBrowsing]; }
54. Session'&'Mul,tasking - (void)applicationDidEnterBackground:(NSNotification *)notification { self.backgroundTaskId = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{ [self teardownSession]; [[UIApplication sharedApplication] endBackgroundTask:self.backgroundTaskId]; self.backgroundTaskId= UIBackgroundTaskInvalid; }]; } - (void)applicationWillEnterForeground:(NSNotification *)notification { // cancel the background task if (self.backgroundTaskId != UIBackgroundTaskInvalid) { [[UIApplication sharedApplication] endBackgroundTask:self.backgroundTaskId]; self.backgroundTaskId = UIBackgroundTaskInvalid; } } - (void)applicationWillTerminate:(NSNotification *)notification { [self teardownSession]; }
55. Working(around(bugs • completely*tear*down*browser*/*adver4ser*/* session*when*no*longer*required • set*delegates*to*nil e.g.: [self.browser stopBrowsingForPeers]; self.browser.delegate = nil; self.browser = nil;
56. iOS$8$/$OS$X$10.10$?
57. If#I#told#you…
58. Finally @GabrielHauber gabriel@ghostdust.com devBlog:)h+p:/ /gabrielhauber.net GitHub:(h*p:/ /github.com/ GabrielHauber
60. Peter
 JavaScriptCore
61. Adding JavaScript to Native Apps CocoaHeads Brisbane X
62. #import <JavaScriptCore/JavaScriptCore.h> • Objective-C (ARC) -> JavaScript (GC) • JavaScript -> Objective-C • Objective-C interface to procedural JavaScriptCore API • Real men don’t need documentation…header files & WWDC session best resources • Is the same as the WebKit JS engine (-Nitro/JIT)
63. • Most interaction via JSContext (hosted by JSVirtualMachine) via JSValue • Thread-safe via locking at JSVirtualMachine granularity • An app can have multiple JSContext in a single JSVirtualMachine, and multiple JSVirtualMachine
64. • Automatic conversion of key foundation types
 NSString=>JS string, NSNumber=>JS number, NSDate=>JS Date etc… • Block=>JS function (avoid capturing JSContext or JSValue in block) • Custom classes via JSExport protocol
65. Demo
66. Caveats • Where is the documentation? WWDC ’14? • Aren’t aware of how to connect WebKit debugger • Pay special attention to retain cycles (JSManagedValue can be used to break cycle) • for…in doesn’t work on NSArray (JS limitation of Prototype?) • Occasionally lose the JSExports of an object which a JSExport property of another object (JSC GC bug?)
68. ! Thanks again meetup.com/cocoaheads @cocoaheadsbne