Beginning iCloud Development - WhyMCA

How does iCloud work? How iCloud can enhance my applications? How should I design interaction with iCloud? When should I use iCloud? Which alternative services include similar features?

http://www.whymca.org/intervento/beginning-icloud-development

Transcript

1. Beginning iCloud development Rocchi Cesare @_funkyboy studiomagnolia.com Monday, July 2, 12
2. Outline What is iCloud? How does it work? Are there alternatives? Monday, July 2, 12
3. Who am I? Monday, July 2, 12
4. UX designer and developer Monday, July 2, 12
5. mnml Monday, July 2, 12
6. < is > Monday, July 2, 12
7. execution matters Monday, July 2, 12
8. lean approach Monday, July 2, 12
9. 1000 details coming together Monday, July 2, 12
10. Giveaway Monday, July 2, 12
11. 1 of the Wenderlich’s raywenderlich.com Monday, July 2, 12
12. Monday, July 2, 12
13. iCloud Storyboards ARC OpenGL ES 2.0 News Stand Turn Based Gaming GameCenter API Monday, July 2, 12
14. twitter.com/_funkyboy cesare@studiomagnolia.com Monday, July 2, 12
15. Giveaway Monday, July 2, 12
16. Giveaway (yes, another) Monday, July 2, 12
17. www.icloudfordevelopers.com Monday, July 2, 12
18. www.icloudfordevelopers.com Conflict Resolution CoreData UIDocument Key-Value store Custom Documents Monday, July 2, 12
19. www.icloudfordevelopers.com twitter.com/_funkyboy cesare@studiomagnolia.com Monday, July 2, 12
20. Who are you? Monday, July 2, 12
21. What is iCloud? Monday, July 2, 12
22. 6028 Startown Rd, Maiden, NC Monday, July 2, 12
23. Stores and synchs stuff Monday, July 2, 12
24. It just works ... Monday, July 2, 12
25. ... when it works Monday, July 2, 12
26. Seamlessness can be a limit Monday, July 2, 12
27. Pros (for devs) No server setup No costs No rumination on synch Monday, July 2, 12
28. Cons (for devs) Stick to a synch model No http API No control on upload Monday, July 2, 12
29. Pros and Cons for users Expectation Monday, July 2, 12
30. Under the hood Monday, July 2, 12
31. Monday, July 2, 12
32. Daemon Monitors changes Works on metadata Shreds files Monday, July 2, 12
33. Special folder, synched Monday, July 2, 12
34. Synched when “appropriate” Monday, July 2, 12
35. Appropriate Which OS? Which connection? Battery status? Monday, July 2, 12
36. Placeholders Monday, July 2, 12
37. Monday, July 2, 12
38. Monday, July 2, 12
39. Information Structure Document Key-value CoreData Monday, July 2, 12
40. UIDocument Monday, July 2, 12
41. UIDocument NSFilePresenter Non-blocking read/write Monday, July 2, 12
42. Monday, July 2, 12
43. -(void) openWithCompletionHandler:^(BOOL success) { } Monday, July 2, 12
44. - (BOOL)loadFromContents:(id)contents ofType:(NSString *)typeName error:(NSError **)outError { } Monday, July 2, 12
45. @interface SMNote : UIDocument Monday, July 2, 12
46. @implementation SMNote - (BOOL)loadFromContents:(id)contents ofType:(NSString *)typeName error:(NSError **)outError { if ([contents length] > 0) { self.myContent = [[NSString alloc] initWithBytes:[contents bytes] length:[contents length] encoding:NSUTF8StringEncoding]; } else { // Default content self.myContent = @"Empty"; } return YES; } Monday, July 2, 12
47. - (BOOL) saveToURL:(NSURL *)url forSaveOperation:UIDocumentSaveForOverwriting completionHandler:^(BOOL success) { } Monday, July 2, 12
48. - (id)contentsForType:(NSString *)typeName error:(NSError **)outError {} Monday, July 2, 12
49. - (id)contentsForType:(NSString *)typeName error:(NSError **)outError { return [NSData dataWithBytes:[self.myContent UTF8String] length:[self.myContent length]]; } Monday, July 2, 12
50. Autosave updateChangeCount: use the methods of the undoManager Monday, July 2, 12
51. @implementation SMNote @synthesize noteContent; // Called whenever the application reads data - (BOOL)loadFromContents:(id)contents ofType:(NSString *)typeName error:(NSError **)outError { } // Called whenever the application (auto)saves the content - (id)contentsForType:(NSString *)typeName error:(NSError **)outError { } Monday, July 2, 12
52. Opening a document Monday, July 2, 12
53. Opening a document Build and run a query Wait for results Unfold results Monday, July 2, 12
54. #import "SMNote.h" @interface SMAppDelegate : UIResponder <UIApplicationDelegate> @property (strong, nonatomic) UIWindow *window; @property (strong, nonatomic) SMViewController *viewController; @property (strong) SMNote *doc; @property (strong) NSMetadataQuery *query; - (void)loadDocument; @end Monday, July 2, 12
55. NSMetadataQuery Monday, July 2, 12
56. - (void)loadDocument { NSMetadataQuery *query = [[NSMetadataQuery alloc] init]; _query = query; [query setSearchScopes:[NSArray arrayWithObject: NSMetadataQueryUbiquitousDocumentsScope]]; } Monday, July 2, 12
57. - (void)loadDocument { NSMetadataQuery *query = [[NSMetadataQuery alloc] init]; _query = query; [query setSearchScopes:[NSArray arrayWithObject: NSMetadataQueryUbiquitousDocumentsScope]]; NSPredicate *pred = [NSPredicate predicateWithFormat: @"%K == %@", NSMetadataItemFSNameKey, kFILENAME]; [query setPredicate:pred]; } Monday, July 2, 12
58. - (void)loadDocument { NSMetadataQuery *query = [[NSMetadataQuery alloc] init]; _query = query; [query setSearchScopes:[NSArray arrayWithObject: NSMetadataQueryUbiquitousDocumentsScope]]; NSPredicate *pred = [NSPredicate predicateWithFormat: @"%K == %@", NSMetadataItemFSNameKey, kFILENAME]; [query setPredicate:pred]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(queryDidFinish:) name:NSMetadataQueryDidFinishGatheringNotification object:query]; [query startQuery]; } Monday, July 2, 12
59. NSPredicate *pred = [NSPredicate predicateWithFormat: @"%K like 'Note_*'", NSMetadataItemFSNameKey]; Monday, July 2, 12
60. Asynchronous! Monday, July 2, 12
61. - (void)queryDidFinish:(NSNotification *)notification { NSMetadataQuery *query = [notification object]; [query disableUpdates]; [query stopQuery]; [[NSNotificationCenter defaultCenter] removeObserver:self name:NSMetadataQueryDidFinishGatheringNotification object:query]; _query = nil; ! [self loadData:query]; } Monday, July 2, 12
62. - (void)loadData:(NSMetadataQuery *)query { if ([query resultCount] == 1) { NSMetadataItem *item = [query resultAtIndex:0]; NSURL *url = [item valueForAttribute:NSMetadataItemURLKey]; SMNote *doc = [[SMNote alloc] initWithFileURL:url]; } } Monday, July 2, 12
63. - (void)loadData:(NSMetadataQuery *)query { if ([query resultCount] == 1) { NSMetadataItem *item = [query resultAtIndex:0]; NSURL *url = [item valueForAttribute:NSMetadataItemURLKey]; self.doc = [[SMNote alloc] initWithFileURL:url]; [self.doc openWithCompletionHandler:^(BOOL success) { if (success) { NSLog(@"iCloud document opened"); } else { NSLog(@"failed opening document from iCloud"); } }]; } } Monday, July 2, 12
64. else { NSURL *ubiq = [[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil]; NSURL *ubiquitousPackage = [[ubiq URLByAppendingPathComponent: @"Documents"] URLByAppendingPathComponent:kFILENAME]; SMNote *doc = [[SMNote alloc] initWithFileURL:ubiquitousPackage]; } Monday, July 2, 12
65. else { NSURL *ubiq = [[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil]; NSURL *ubiquitousPackage = [[ubiq URLByAppendingPathComponent: @"Documents"] URLByAppendingPathComponent:kFILENAME]; SMNote *doc = [[SMNote alloc] initWithFileURL:ubiquitousPackage]; self.doc = doc; [doc saveToURL: [doc fileURL] forSaveOperation:UIDocumentSaveForCreating completionHandler:^(BOOL success) { if (success) { [doc openWithCompletionHandler:^(BOOL success) { NSLog(@"new document opened from iCloud"); }]; } }]; } Monday, July 2, 12
66. - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { ... [self.window makeKeyAndVisible]; NSURL *ubiq = [[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil]; if (ubiq) { NSLog(@"iCloud access at %@", ubiq); [self loadDocument]; } else { NSLog(@"No iCloud access"); } return YES; } Monday, July 2, 12
67. - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { ... [self.window makeKeyAndVisible]; NSURL *ubiq = [[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil]; if (ubiq) { NSLog(@"iCloud access at %@", ubiq); [self loadDocument]; } else { NSLog(@"No iCloud access"); } return YES; } Monday, July 2, 12
68. - (void)viewDidLoad { [super viewDidLoad]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(dataReloaded:) name:@"noteModified" object:nil]; } - (void)dataReloaded:(NSNotification *)notification { self.doc = notification.object; self.noteView.text = self.doc.noteContent; } Monday, July 2, 12
69. Switching on/off Monday, July 2, 12
70. - (NSURL *) localNotesURL { return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject]; } - (NSURL *) ubiquitousNotesURL { return [[[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil] URLByAppendingPathComponent:@"Documents"]; } Monday, July 2, 12
71. - (void) setNoteUbiquity { NSURL *baseUrl = [self localNotesURL]; if (_useiCloud) baseUrl = [self ubiquitousNotesURL]; NSURL *destUrl = [baseUrl URLByAppendingPathComponent: [note.fileURL lastPathComponent]]; [[NSFileManager defaultManager] setUbiquitous:_useiCloud itemAtURL:note.fileURL destinationURL:destUrl error:NULL]; } Don’t call it on the main thread! Monday, July 2, 12
72. - (void) startMigration { NSOperationQueue *iCloudQueue = [NSOperationQueue new]; NSInvocationOperation *op = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(setNoteUbiquity) object:nil]; [iCloudQueue addOperation:op]; } Monday, July 2, 12
73. Custom documents Monday, July 2, 12
74. SMNotesDocument SMNote SMNote SMNote ... Monday, July 2, 12
75. @interface SMNote : NSObject <NSCoding> @property (copy, nonatomic) NSString *noteId; @property (copy, nonatomic) NSString *noteContent; @property (strong, nonatomic) NSDate *createdAt; @property (strong, nonatomic) NSDate *updatedAt; @end Monday, July 2, 12
76. #import "SMNote.h" @interface SMNotesDocument : UIDocument @property (nonatomic, strong) NSMutableArray *entries; @property (nonatomic, strong) NSFileWrapper *fileWrapper; @end Monday, July 2, 12
77. #import "SMNote.h" @interface SMNotesDocument : UIDocument @property (nonatomic, strong) NSMutableArray *entries; @property (nonatomic, strong) NSFileWrapper *fileWrapper; @end Monday, July 2, 12
78. - (id)contentsForType:(NSString *)typeName error:(NSError **)outError { NSMutableDictionary *w = [NSMutableDictionary dictionary]; NSMutableData *data = [NSMutableData data]; NSKeyedArchiver *arch = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data]; [arch encodeObject:_entries forKey:@"entries"]; [arch finishEncoding]; } Monday, July 2, 12
79. - (id)contentsForType:(NSString *)typeName error:(NSError **)outError { NSMutableDictionary *w = [NSMutableDictionary dictionary]; NSMutableData *data = [NSMutableData data]; NSKeyedArchiver *arch = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data]; [arch encodeObject:_entries forKey:@"entries"]; [arch finishEncoding]; NSFileWrapper *entriesWrapper = [[NSFileWrapper alloc] initRegularFileWithContents:data]; [w setObject:entriesWrapper forKey:@"notes.dat"]; // add other wrappers if you like NSFileWrapper *res = [[NSFileWrapper alloc] initDirectoryWithFileWrappers:w]; return res; } Monday, July 2, 12
80. - (BOOL)loadFromContents:(id)contents ofType:(NSString *)typeName error:(NSError **)outError { NSFileWrapper *wrapper = (NSFileWrapper *)contents; NSDictionary *d = [wrapper fileWrappers]; NSFileWrapper *entriesWrap = [d objectForKey:@"notes.dat"]; } Monday, July 2, 12
81. - (BOOL)loadFromContents:(id)contents ofType:(NSString *)typeName error:(NSError **)outError { NSFileWrapper *wrapper = (NSFileWrapper *)contents; NSDictionary *d = [wrapper fileWrappers]; NSFileWrapper *entriesWrap = [d objectForKey:@"notes.dat"]; NSData *data = [entriesWrap regularFileContents]; NSKeyedUnarchiver *arch = [[NSKeyedUnarchiver alloc] initForReadingWithData:data]; _entries = [arch decodeObjectForKey:@"entries"]; // Notify the view } Monday, July 2, 12
82. Uniform Type Identifier Monday, July 2, 12
83. Monday, July 2, 12
84. Key-value Monday, July 2, 12
85. Key-value 1Mb Monday, July 2, 12
86. Key-value 1Mb was 64Kb ! Monday, July 2, 12
87. - (void) saveNoteAsCurrent { [[NSUbiquitousKeyValueStore defaultStore] setString:self.currentNote.noteId forKey:@"com.studiomagnolia.currentNote"]; [[NSUbiquitousKeyValueStore defaultStore] synchronize]; } Monday, July 2, 12
88. - (void) saveNoteAsCurrent { [[NSUbiquitousKeyValueStore defaultStore] setString:self.currentNote.noteId forKey:@"com.studiomagnolia.currentNote"]; [[NSUbiquitousKeyValueStore defaultStore] synchronize]; } NSString *currentNoteId = [[NSUbiquitousKeyValueStore defaultStore] stringForKey: @"com.studiomagnolia.currentNote"]; Monday, July 2, 12
89. NSUbiquitousKeyValueStore* store = [NSUbiquitousKeyValueStore defaultStore]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(updateCurrentNoteIfNeeded:) name:NSUbiquitousKeyValueStoreDidChangeExternallyNotification object:store]; [store synchronize]; Monday, July 2, 12
90. Conflict Resolution Monday, July 2, 12
91. Conflict Resolution Up to the dev documentState Monday, July 2, 12
92. DocumentStates UIDocumentStateNormal UIDocumentStateClosed UIDocumentStateInConflict UIDocumentStateSavingError UIDocumentStateEditingDisabled Monday, July 2, 12
93. UIDocumentStateChangedNotification Monday, July 2, 12
94. [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(noteHasChanged:) name:UIDocumentStateChangedNotification object:nil]; Monday, July 2, 12
95. UIDocumentState s = [n documentState]; switch (s) { case UIDocumentStateNormal: NSLog(@"Everything is fine"); break; case UIDocumentStateInConflict: NSLog(@"There is a conflict"); break; ... default: NSLog(@"Unknown state"); break; } Monday, July 2, 12
96. UI conflict vs iCloud conflict Monday, July 2, 12
97. Resolution policy last wins prompt user automatic merge Monday, July 2, 12
98. Resolution policy last wins prompt user automatic merge NSFileVersion Monday, July 2, 12
99. NSError *err; NSURL *url = [[NSFileManager defaultManager] URLForPublishingUbiquitousItemAtURL:[self.currentNote fileURL] expirationDate:&expirationInOneHourSinceNow error:&err]; Monday, July 2, 12
100. Monday, July 2, 12
101. Tips & Tricks Monday, July 2, 12
102. Patience! Monday, July 2, 12
103. Test on wireless & 3G Monday, July 2, 12
104. Regenerate provisioning Monday, July 2, 12
105. Delete previous data Monday, July 2, 12
106. Monday, July 2, 12
107. Restart device Monday, July 2, 12
108. API throttle! Monday, July 2, 12
109. App policy Be gentle with storage <App_home>/tmp <App_home>/Library/Caches/ Monday, July 2, 12
110. App policy Documents is backed up mark files as “do not backup” Monday, July 2, 12
111. // iOS 5.0.1 #import <sys/xattr.h> - (BOOL)addSkipBackupAttributeToItemAtURL:(NSURL *)URL { const char* filePath = [[URL path] fileSystemRepresentation]; const char* attrName = "com.apple.MobileBackup"; u_int8_t attrValue = 1; int result = setxattr(filePath, attrName, &attrValue, sizeof(attrValue), 0, 0); return result == 0; } Monday, July 2, 12
112. // iOS 5.1 - (BOOL)addSkipBackupAttributeToItemAtURL:(NSURL *)URL { NSError *error = nil; BOOL success = [URL setResourceValue: [NSNumber numberWithBool:YES] forKey: NSURLIsExcludedFromBackupKey error: &error]; if(!success){ NSLog(@"Error excluding %@ from backup %@", [URL lastPathComponent], error); } return success; } Monday, July 2, 12
113. “To iCloud or not to iCloud?” Monday, July 2, 12
114. Alternatives Monday, July 2, 12
115. Alternatives dropbox parse.com cloudmine stackmob custom Monday, July 2, 12
116. Dropbox documents authentication no notifications Monday, July 2, 12
117. Dropbox other platforms no CR (revision #) expectation Monday, July 2, 12
118. Parse Monday, July 2, 12
119. Parse ORM approach Recently released No cost of infrastructure Monday, July 2, 12
120. Parse Pay as you use Limit of calls/mo Monday, July 2, 12
121. PFObject *note = [PFObject objectWithClassName:@"Note"]; [note setObject:@"Ciao" forKey:@"title"]; [note setObject:@"Note on Parse" forKey:@"content"]; [note save]; //[note saveInBackground]; //[note saveEventually]; Monday, July 2, 12
122. [note saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) { if (error) { NSLog(@"Note not saved"); } else { NSLog(@"Note saved successfully"); } }]; Monday, July 2, 12
123. Parse Other platforms REST API Push notifications Object browser Monday, July 2, 12
124. curl -X POST \ -H "X-Parse-Application-Id: ${APPLICATION_ID}" \ -H "X-Parse-REST-API-Key: ${REST_API_KEY}" \ -H "Content-Type: application/json" \ -d '{"note": 001, "title": "Ciao", "content": “Note on parse” }' \ https://api.parse.com/1/classes/GameScore Monday, July 2, 12
125. PFObject *note = [PFObject objectWithClassName:@"Note"]; [note setObject:@"Ciao" forKey:@"title"]; [note setObject:@"Note on parse" forKey:@"content"]; PFObject *myTag = [PFObject objectWithClassName:@"Tag"]; [myTag setObject:@"important" forKey:@"tagName"]; // Add a relation [note setObject:myTag forKey:@"tag"]; // Saves both [note saveInBackground]; Monday, July 2, 12
126. Recap UIDocument Key-Value store Alternatives Monday, July 2, 12
127. “You can’t always get what you want but if you try sometime, you just might find ...” Monday, July 2, 12
128. “You can’t always get what you want but if you try sometime, you just might find ...” Rolling Stones Monday, July 2, 12
129. Contact twitter.com/_funkyboy cesare@studiomagnolia.com http://studiomagnolia.com Monday, July 2, 12