ARC & Blocks 時代の ベストプラクティスを考える

ARC & Blocks を使ったときの循環参照を避けるための現実的なサンプル。

1. ؛઒ࠀݾ http://kishikawakatsumi.com Twitter @k_katsumi 24/7 twenty-four seven http://d.hatena.ne.jp/KishikawaKatsumi/
2. ARC & Blocks ࣌୅ͷ ϕετϓϥΫςΟεΛߟ͑Δ
3. ۩ମతͳίʔυ͔Β ॥؀ࢀরΛආ͚ΔͨΊͷ ৼΔ෣͍ͷҧ͍Λ࠶֬ೝ͢Δ
4. ࢀߟจݙ
5. ॻ੶ ΤΩεύʔτObjective-Cϓϩάϥϛϯά ― iOS/OS Xͷ ϝϞϦ؅ཧͱϚϧνεϨου ࡔຊҰथ http://tatsu-zine.com/books/objc
6. Apple ެࣜυΩϡϝϯτ Transitioning to ARC Release Notes http://developer.apple.com/library/ios/#releasenotes/ObjectiveC/RN-TransitioningToARC/Introduction/Introduction.html ϒϩοΫϓϩάϥϛϯάτϐοΫ https://developer.apple.com/jp/devcenter/ios/library/documentation/Blocks.pdf%2FBlocks.pdf&ei=5ua_T_PnAa6CmQWB-dyiCg&usg=AFQjCNEB7EtpLn4Qt4N22nDrqs33gy1orA Clang ެࣜυΩϡϝϯτ Automatic Reference Counting http://clang.llvm.org/docs/AutomaticReferenceCounting.html ninjinkun ͷεϥΠυ iOSͱAutomatic Reference Countingʹ͍ͭͯൃද͠·ͨ͠ http://ninjinkun.hatenablog.com/entry/2011/11/19/171246
7. ARCͱ͸
8. •Automatic Reference Counting •ϝϞϦ؅ཧΛࣗಈԽ͢Δ ʢ੩తղੳʹΑͬͯίϯύΠϥ͕ࣗಈతʹอ࣋/ղ์ͷ ίʔυΛૠೖ͢Δʣ •όΠφϦޓ׵ੑ͕͋Δ ʢARCΦϯͷόΠφϦͱΦϑͷόΠφϦΛϦϯΫͰ͖Δ, ίϯύΠϧ୯ҐͰARCΛΦϯ/ΦϑͰ͖Δʣ •Weak referencesҎ֎͸Mac OS X v10.6 ͱ iOS 4Ͱ΋ ࢖͑Δ
9. ARCΦϯͰBlocksΛ࢖͏৔߹ ॥؀ࢀরΛ࡞Γ΍͍͢
10. ॥؀ࢀরΛආ͚ΔͨΊͷ νΣοΫϦετ
11. •ϒϩοΫ಺ͰϒϩοΫͷݺͼग़͠ݩΛ ࢀরͯ͠Δ͔Ͳ͏͔ •ϒϩοΫΛίϐʔ͍ͯ͠Δ͔Ͳ͏͔ •ϒϩοΫͷݺͼग़͠ݩͷΦϒδΣΫτΛ อ͍࣋ͯ͠Δ͔Ͳ͏͔ •ϒϩοΫ಺ͰselfΛࢀর͍ͯ͠Δ͔Ͳ͏͔
12. ϒϩοΫ಺ͰϒϩοΫͷݺͼग़͠ݩΛ ࢀর͍ͯ͠Δ৔߹
13. ʢྫʣASIHTTPRequest
14. - (void)grabURLInBackground { NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"]; ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [request setCompletionBlock:^ { NSString *responseString = [request responseString]; // ŋŋŋ }]; [request setFailedBlock:^ { NSError *error = [request error]; // ŋŋŋ }]; [request startAsynchronous]; } ARC Non ARC request ΦϒδΣΫτ͕॥؀ࢀর
15. - (void)grabURLInBackground { NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"]; __block ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [request setCompletionBlock:^ { NSString *responseString = [request responseString]; // ŋŋŋ }]; [request setFailedBlock:^ { NSError *error = [request error]; // ŋŋŋ }]; [request startAsynchronous]; } http://allseeing-i.com/ASIHTTPRequest/How-to-use ARC Non ARC ARC͕ແޮͷ৔߹͸ __block ͕ࢦఆ͞Εͨ ΦϒδΣΫτ͸ retain ͞Εͳ͍
16. - (void)grabURLInBackground { NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"]; __block ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [request setCompletionBlock:^ { // Use when fetching text data NSString *responseString = [request responseString]; // ŋŋŋ request = nil; }]; [request setFailedBlock:^ { NSError *error = [request error]; // ŋŋŋ request = nil; }]; [request startAsynchronous]; } ARC Non ARC
17. - (void)grabURLInBackground { NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"]; __weak ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [request setCompletionBlock:^ { // Use when fetching text data NSString *responseString = [request responseString]; // ŋŋŋ }]; [request setFailedBlock:^ { NSError *error = [request error]; // ŋŋŋ }]; [request startAsynchronous]; } ARC Non ARC
18. - (void)grabURLInBackground { NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"]; __unsafe_unretained ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [request setCompletionBlock:^ { // Use when fetching text data NSString *responseString = [request responseString]; // ŋŋŋ }]; [request setFailedBlock:^ { NSError *error = [request error]; // ŋŋŋ }]; [request startAsynchronous]; } ARC Non ARC
19. ϓϥΫςΟε̍ ݁ՌΛϒϩοΫͷҾ਺Ͱฦ͢
20. ATService *service = [[ATService alloc] init]; service.completionBlock = ^(NSString *results, NSError *error) { if (!error) { self.tweets = results; [tableView reloadData]; } }; [service grabURLInBackground]; ݁ՌΛϒϩοΫͷҾ਺Ͱฦ͢ ARC Non ARC
21. @implementation ATService @synthesize completionBlock; - (void)grabURLInBackground { NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"]; __weak ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [request setCompletionBlock:^{ NSArray *results = [request.responseData objectFromJSONData]; if (completionBlock) { completionBlock(responseString, nil); } }]; [request setFailedBlock:^{ NSError *error = [request error]; if (completionBlock) { completionBlock(nil, error); } }]; [request startAsynchronous]; } ʢࢀߟʣϥούʔଆͷ࣮૷
22. ϒϩοΫΛίϐʔ͍ͯ͠Δ͔Ͳ͏͔
23. - (void)grabURLInBackground { NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"]; __weak ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [request setCompletionBlock:^ { // Use when fetching text data NSString *responseString = [request responseString]; // ŋŋŋ }]; [request setFailedBlock:^ { NSError *error = [request error]; // ŋŋŋ }]; [request startAsynchronous]; } ARC ϒϩοΫΛίϐʔ͍ͯ͠Δ Non ARC
24. ATService *service = [[ATService alloc] init]; service.completionBlock = ^(NSString *results, NSError *error) { if (!error) { self.tweets = results; [tableView reloadData]; } }; [service grabURLInBackground]; ϒϩοΫΛίϐʔ͍ͯ͠Δ ARC Non ARC
25. ϒϩοΫΛίϐʔͨ͠৔߹ ݺͼग़͠ݩΛࢀর͢Δͱ ॥؀ࢀর͢Δ ARC Non ARC
26. ϓϥΫςΟε̎ ʢͰ͖Δ͚ͩʣϒϩοΫΛ ίϐʔ͠ͳ͍
27. ATService *service = [[ATService alloc] init]; [service grabURLWithCompletionBlock:^(NSArray *results, NSError *error) { self.tweets = results; [self.tableView reloadData]; [service log]; }]; ϒϩοΫΛίϐʔ͠ͳ͍ ARC Non ARC
28. - (void)grabURLInBackgroundWithCompletionBlock:(ATServiceResultsBlock)block { NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"]; __weak ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [request setCompletionBlock:^{ NSString *responseString = [request responseString]; if (block) { block(responseString, nil); } }]; [request setFailedBlock:^{ NSError *error = [request error]; if (block) { block(nil, error); } }]; [request startAsynchronous]; } ʢࢀߟʣϥούʔଆͷ࣮૷
29. ϒϩοΫͷݺͼग़͠ݩͷ ΦϒδΣΫτΛอ͍࣋ͯ͠Δ͔Ͳ͏͔
30. ϒϩοΫ಺Ͱ selfΛࢀর͍ͯ͠Δ͔Ͳ͏͔
31. [service grabURLInBackgroundWithCompletionBlock:^(NSArray *results, NSError *error) { self.tweets = results; [self.tableView reloadData]; [service log]; }]; ARC Non ARC @interface ATDetailViewController () { ATService *service; } @end ϒϩοΫͷݺͼग़͠ݩΛอ͍࣋ͯͯ͠΋ϒϩοΫ͕ ίϐʔ͞Εͳ͍ͳΒΩϟϓνϟ͞Εͨࣗಈม਺͸ ϒϩοΫͷείʔϓΛൈ͚ͨͱ͖ʹղ์͞ΕΔ
32. service.completionBlock = ^(NSArray *results, NSError *error) { self.tweets = results; [self.tableView reloadData]; [service log]; }; [service grabURLInBackground]; ARC Non ARC @interface ATDetailViewController () { ATService *service; } @end ϒϩοΫͷݺͼग़͠ݩΛอ͍࣋ͯͯ͠ɺϒϩοΫ͕ ίϐʔ͞ΕΔ৔߹͸॥؀ࢀরͱͳΔ
33. ϓϥΫςΟε̏ղܾํ๏ self Λ __weak (__unsafe_unretained) ࢦఆͷϩʔΧϧม਺ʹ୅ೖ͢Δ
34. __weak ATDetailViewController *me = self; service.completionBlock = ^(NSArray *results, NSError *error) { me.tweets = results; [me.tableView reloadData]; [me.service log]; }; [service grabURLInBackground]; ARC Non ARC @interface ATDetailViewController () { ATService *service; } @end ॥؀ࢀরΛආ͚ΔͨΊʹ self ΛϩʔΧϧม਺ʹ୅ೖͯ͠ ϩʔΧϧม਺Λ௨ͯ͠ΞΫηε͢Δ
35. UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect]; [button setTitle:@"Show ActionSheet" forState:UIControlStateNormal]; [button addEventHandler:^(id sender) { UIActionSheet *actionSheet = [UIActionSheet actionSheetWithTitle:@"Title"]; [actionSheet setCancelButtonIndex:[actionSheet addButtonWithTitle:@"Close"]]; [actionSheet showInView:self.view]; } forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:button]; ARC Non ARC BlocksKit ͷ UIKit ֦ுͳͲ ίʔϧόοΫͰUIΛߋ৽͢Δ৔߹ʹ ॥؀ࢀরΛ࡞Γ͕ͪ
36. ATDetailViewController __weak *me = self; UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect]; [button setTitle:@"Show ActionSheet" forState:UIControlStateNormal]; [button addEventHandler:^(id sender) { UIActionSheet *actionSheet = [UIActionSheet actionSheetWithTitle:@"Title"]; [actionSheet setCancelButtonIndex:[actionSheet addButtonWithTitle:@"Close"]]; [actionSheet showInView:self.view]; } forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:button]; ARC Non ARC self Λ͍ͬͨΜ weak ͳϩʔΧϧม਺ʹ୅ೖ͢Δɻ ӈล΍Ҿ਺ʹग़ݱ͢Δ self ͸ݟམͱ͠΍͍͢
37. - (void)settingsButtonClicked:(id)sender { __unsafe_unretained TTTickerWindowController *me = self; settingsViewController = [[TTSettingsWindowController alloc] init]; settingsViewController.settings = settings; [settingsViewController sheetModalForWindow:self.window completionHandler:^(TTTickerSettings *result) { me.settings = result; me.tickerViewController.settings = result; if (me.settings.floatingWindow) { [me.window setLevel:CGShieldingWindowLevel() + 1]; } else { [me.window setLevel:NSNormalWindowLevel]; } }]; } ARC Non ARC Mac ͷ৔߹ɺLionҎ্Ͱ΋ __weak ࢦఆͷͰ͖ͳ͍ Ϋϥε͕͚ͬ͜͏͋Δ (__unsafe_unretained Λ࢖͏)
38. ϓϥΫςΟε̐ delegate ΍ target actionͰ ࣮૷͢Δ͜ͱΛݕ౼͢Δ
39. Blocks ͷ࢖͍ํ͸ ՄಡੑͱνʔϜϝϯόʔͷ ྗྔͳͲ͍Ζ͍Ζͳ όϥϯεΛݟۃΊͯ ࢖͍෼͚ΒΕΔΑ͏ʹ͍ͨ͠
40. ϓϥΫςΟε̑ Ϋϥεϝιουʹ͢Δ
41. [EPATNDAPIClient eventsWithKeyword:keyword completionBlock:^(NSArray *results, NSError *error) { if (!error) { NSArray *events = [self saveEvents:results]; [[EPCoreDataManager sharedManager] saveContext]; } }]; Ϋϥεϝιουʹ͢Δͱ ࢖͏΄͏͸͍Ζ͍Ζߟ͑ͳͯ͘ϥΫ ARC Non ARC
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43. ෳ਺ͷϑΝΠϧʹ ίϯύΠϥΦϓγϣϯΛઃఆ͢Δʹ͸
44. Build PhasesʼCompile Sources Ͱ ෳ਺ͷϑΝΠϧΛબ୒ͯ͠...
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