![Getting Settings data
Easy, using the NSUserDefaults class
NSUserDefaults *defaults =
[NSUserDefaults standardUserDefaults];
defaultsbecomes a dictionary, so we can
do stuff like:
(NSString *) objectForKey:
(NSDate *) objectForKey:
(int) intForKey:
(BOOL) boolForKey:](https://image.slidesharecdn.com/settingsanddefaults-091027001153-phpapp01/85/iPhone-Dev-Application-Settings-and-Defaults-21-320.jpg)
![MainViewController.m
- (void) refreshFields {
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
usernameLabel.text = [defaults objectForKey: kUsernameKey];
passwordLabel.text = [defaults objectForKey: kPasswordKey];
languageLabel.text = [defaults objectForKey: kLanguageKey];
beAwesomeLabel.text = [defaults objectForKey: kBeAwesomeKey];
awesomenessLabel.text = [[defaults objectForKey: kAwesomenessKey]
stringValue];
}
- (void) viewDidAppear:(BOOL)animated {
[self refreshFields];
[super viewDidAppear:animated];
}](https://image.slidesharecdn.com/settingsanddefaults-091027001153-phpapp01/85/iPhone-Dev-Application-Settings-and-Defaults-24-320.jpg)
![MainViewController.m
- (void) refreshFields {
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
usernameLabel.text = [defaults objectForKey: kUsernameKey];
passwordLabel.text = [defaults objectForKey: kPasswordKey];
languageLabel.text = [defaults objectForKey: kLanguageKey];
beAwesomeLabel.text = [defaults objectForKey: kBeAwesomeKey];
awesomenessLabel.text = [[defaults objectForKey: kAwesomenessKey]
stringValue]; ‹ don’t forget stringValue
}
- (void) viewDidAppear:(BOOL)animated {
[self refreshFields];
[super viewDidAppear:animated];
}](https://image.slidesharecdn.com/settingsanddefaults-091027001153-phpapp01/85/iPhone-Dev-Application-Settings-and-Defaults-25-320.jpg)
![Get what’s there when view loads
FlipsideViewController.m
- (void)viewDidLoad {
[super viewDidLoad];
NSUserDefaults *defaults = [NSUserDefaults
standardUserDefaults];
awesomeSwitch.on = ([[defaults objectForKey:kBeAwesomeKey]
isEqualToString:@"Oui"]) ? YES: NO;
awesomenessSlider.value = [defaults
floatForKey:kAwesomenessKey];
}](https://image.slidesharecdn.com/settingsanddefaults-091027001153-phpapp01/85/iPhone-Dev-Application-Settings-and-Defaults-28-320.jpg)
![Set new values when moving out
FlipsideViewController.m
- (void) viewWillDisappear:(BOOL)animated {
NSUserDefaults *defaults = [NSUserDefaults
standardUserDefaults];
NSString *prefValue = (awesomeSwitch.on)? @"Oui" :
@"Non";
[defaults setObject:prefValue forKey:kBeAwesomeKey];
[defaults setFloat:awesomenessSlider.value
forKey:kAwesomenessKey];
[super viewWillDisappear:animated];
}](https://image.slidesharecdn.com/settingsanddefaults-091027001153-phpapp01/85/iPhone-Dev-Application-Settings-and-Defaults-29-320.jpg)
iPhone Dev: Application Settings and Defaults
- 1. Application Settings and User Defaults - Parimal Satyal (realityequation.net) October 28, 2009 Based on Chapter 10 ‘Application Settings and User Defaults’ Apress Beginning iPhone 3 Development: Exploring the iPhone SDK by Dave Mark and Jeff LaMarch
- 2. Prefs Most Mac apps have ‘Preferences’ Persistent Data/Settings Settings app on iPhone OS UI is built for you, uses plist
- 3. Settings Apps can have own tab in the Settings app When in-app, when in Settings app? ‘Backdoor’ prefs that don’t need changing Else, users must quit
- 5. Utility App Goodness Free UI Free ‘flip side view’ (animated) Custom UIView subclasses: MainView FlipsideView
- 7. Settings Bundle ‘Settings Bundle’ to provide the data Each bundle must have Root.plist Additional views through additional plists as child views in Root.plist
- 8. New File > Resource
- 9. Root.plist Format Root node is always a dictionary (so must have key and value) Children nodes can be: Dictionaries • capable of containing other data Arrays • capable of containing other data Boolean Data Number String StringsTable for localization; ignore
- 12. PreferenceSpecifiers - Required: Type, Key, (Title)
- 13. PreferenceSpecifiers Key Key - Required: Type, Key, (Title) - Key vs Key: Confusing
- 14. Adding Stuff and Grouping Notice change in icons when expanded PSGroupSpecifier signals new group The contents of Root.plist determine the UI and structure of Settings app
- 15. Other Inputs Secure Text Field (isSecure key) Multivalue field: PSMultiValueSpecifier Array as child, with separate Key list and Value list Toggle Switch: PSToggleSwitchSpecifier Slider: PSSliderSpecifier
- 18. Array to Drill Down
- 20. Magic of Root.plist Open Root.plist Spend some time playing around and seeing what changes what Add another control: A Toggle, a Slider or just a Text Field
- 21. Getting Settings data Easy, using the NSUserDefaults class NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; defaultsbecomes a dictionary, so we can do stuff like: (NSString *) objectForKey: (NSDate *) objectForKey: (int) intForKey: (BOOL) boolForKey:
- 22. UI: MainView.xib
- 23. MainViewController Explore the .h and .m files Take a look at these methods: refreshFields: flipSideViewControllerDidFinish: viewDidAppear: Declaring constants, creating a method Property-ize and synthesize elements Map them using NSUserDefaults class & objectForKey: method
- 24. MainViewController.m - (void) refreshFields { NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; usernameLabel.text = [defaults objectForKey: kUsernameKey]; passwordLabel.text = [defaults objectForKey: kPasswordKey]; languageLabel.text = [defaults objectForKey: kLanguageKey]; beAwesomeLabel.text = [defaults objectForKey: kBeAwesomeKey]; awesomenessLabel.text = [[defaults objectForKey: kAwesomenessKey] stringValue]; } - (void) viewDidAppear:(BOOL)animated { [self refreshFields]; [super viewDidAppear:animated]; }
- 25. MainViewController.m - (void) refreshFields { NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; usernameLabel.text = [defaults objectForKey: kUsernameKey]; passwordLabel.text = [defaults objectForKey: kPasswordKey]; languageLabel.text = [defaults objectForKey: kLanguageKey]; beAwesomeLabel.text = [defaults objectForKey: kBeAwesomeKey]; awesomenessLabel.text = [[defaults objectForKey: kAwesomenessKey] stringValue]; ‹ don’t forget stringValue } - (void) viewDidAppear:(BOOL)animated { [self refreshFields]; [super viewDidAppear:animated]; }
- 26. Changing Defaults Design UI Create outlets Use getters and setters to make the changes
- 27. FlipsideView.xib
- 28. Get what’s there when view loads FlipsideViewController.m - (void)viewDidLoad { [super viewDidLoad]; NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; awesomeSwitch.on = ([[defaults objectForKey:kBeAwesomeKey] isEqualToString:@"Oui"]) ? YES: NO; awesomenessSlider.value = [defaults floatForKey:kAwesomenessKey]; }
- 29. Set new values when moving out FlipsideViewController.m - (void) viewWillDisappear:(BOOL)animated { NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; NSString *prefValue = (awesomeSwitch.on)? @"Oui" : @"Non"; [defaults setObject:prefValue forKey:kBeAwesomeKey]; [defaults setFloat:awesomenessSlider.value forKey:kAwesomenessKey]; [super viewWillDisappear:animated]; }
- 30. Finishing Up Clean up with dealloc, viewDidUnload for both Views Fix any Build errors And you get...