iOS 7 Development Crash Course

3 hour talk (including live tools & coding demo) gave to Software Engineering University Students on iOS Development for a course in Mobile Development.

The topics cover the technologies needed to tackle a 1 month App project.

* Objective-C rundown (assumes some previous knowledge)
* NSURLSession
* NSURLSessionTask
* NSCoding
* Blocks & Delegation
* CLLocationManager

PS: Re-used slides of my Auto Layout presentation since that one never saw the light out of Hop.in (current employer).

Transcript

1. CRASH COURSE iOS 7 DEV the By Nicolas Goles
2. • Objective-C • MVC • Delegation & Blocks • HTTP • Persistence • Geolocation • Xcode • Interface Builder CONTENTS
3. OBJECTIVE-C what’s
4. OBJECTIVE-C •Superset of the C programming language. ! •Adds syntax for object-oriented capabilities. ! •Provides dynamic typing and binding. ! •Defers many responsibilities until runtime. * Objective-C Intro
5. “In Objective-C one does not simply call a method; one sends a message…” And :)
6. POP QUIZ •How to log a message to the console? ! •How do we call a method in Objective-C? ! •How do we declare a Class in Objective-C?
7. NSLog(@“Is there anybody out there?”); console log:
8. [NSLayoutConstraint constraintWithItem:view1 attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:view2 attribute: NSLayoutAttributeHeight multiplier:0.5 constant:0]; method call:
9. // Often in Foo.h @interface Foo : NSObject ! @end ! // Often in Foo.m @implementation Foo ! @end Class
10. what’s what’s COCOA TOUCH
11. Cocoa Touch Complete Assortment of Frameworks for building iOS Applications. * Cocoa Touch Layer
12. Audio & Video Data Management Graphics User Applications Networking
13. what’s Why MVC
14. MVC Basic Design Pattern to build an iOS App.
15. MVC ! View ! Controller ! Model User Action Updates Notify Notify
16. what’s BLOCKS & DELEGATES let’s start…
17. DELEGATION •Base communication pattern used by the iOS APIs. •Customize an object’s behavior and be notified about certain events.
18. ! // Foo.h @interface Foo : UITableViewController <UIAlertViewDelegate> ! @end ! // Foo.m @implementation Foo - (void)showAlert { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Test Alert" message:@"EHLO :)" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } @end eg:
19. // // Foo.m // ! @implementation Foo ! - (void)showAlert { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Test Alert" message:@"EHLO :)" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; // Will show Alert View } ! // Delegate Method - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex { NSLog(@"User pressed Alert’s View button # %d!”, buttonIndex); } ! @end eg:
20. BLocks
21. BLOCKS •“New” to Objective-C* •Can often do what could be implemented using delegation.** * iOS 4+ ** Both delegation & blocks have their advantages & requirements.
22. - (void)foo { int (^aBlock)(int) = ^(int num) { return num *2; }; } Return Value Block Variable Name Block Parameters Block Parameters (with names) Block Definition assigned to var “aBlock”. BLOCKS
23. - (void)foo { int (^myBlock)(int) = ^(int num) { return num * 2; }; int four = myBlock(2); // 2*2 == 4 } eg: BLOCKS
24. what’s HTTP how to…
25. NSURLSession The NSURLSession class and related classes provide an API for downloading content via HTTP.* * iOS 7+
26. NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration]; config.HTTPAdditionalHeaders = @{@"Accept" : @"text/json"}; _session = [NSURLSession sessionWithConfiguration:config delegate:nil delegateQueue:nil]; config NSURLSession
27. NSURLSessionTask NSURLSessionTask NSURLSessionDataTask NSURLSessionDataTask NSURLSessionUploadTask NSURLSessionDownloadTask
28. NSURL *URL = [NSURL URLWithString:@"http://example.com"]; NSURLRequest *request = [NSURLRequest requestWithURL:URL]; ! NSURLSession *session = [NSURLSession sharedSession]; NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler: ^(NSData *data, NSURLResponse *response, NSError *error) { // ... }]; [task resume]; GET NSURLSessionTask
29. NSURL *URL = [NSURL URLWithString:@"http://example.com/json_service"]; NSURLRequest *request = [NSURLRequest requestWithURL:URL]; ! NSURLSession *session = [NSURLSession sharedSession]; __block NSDictionary *JSON; NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler: ^(NSData *data, NSURLResponse *response, NSError *error) { //Remember to Check for HTTP errors or NSError NSError *parsingError; JSON = [NSJSONSerialization JSONObjectWithData:data options:0 error:&parsingError]; if (!JSON) { NSLog(@"Handle Error %@", [parsingError localizedDescription]); } NSLog(@"%@", JSON[@"Some Key"]); }]; ! [task resume]; JSON NSURLSessionTask
30. what’s PERSIST DATA how to…
31. NSKeyedArchiver Entity Modeling: NO Querying: NO Speed: Slow* Serialization Format: NSData Migrations: Manual * Speed is somewhat relative… but no, NSKeyedArchiver is not the Ferrari of Serialization.
32. NSKeyedArchiver Does the Job: YES Painful to Use: NO * http://nshipster.com/nscoding/
33. NSKeyedArchiver Simple 2 method @protocol -initWithCoder: encodeWithCoder:
34. NSCoding @interface Book : NSObject <NSCoding> @property NSString *title; @property NSUInteger pageCount; @property NSSet *categories; @end ! @implementation Book ! // NSCoding - (instancetype)initWithCoder:(NSCoder *)decoder { self = [super init]; if (!self) { return nil; } ! self.title = [decoder decodeObjectForKey:@"title"]; self.pageCount = [decoder decodeIntegerForKey:@"pageCount"]; self.categories = [decoder decodeObjectForKey:@"categories"]; ! return self; } ! - (void)encodeWithCoder:(NSCoder *)encoder { [encoder encodeObject:self.title forKey:@"title"]; [encoder encodeInteger:self.pageCount forKey:@"pageCount"]; [encoder encodeObject:self.categories forKey:@"categories"]; } ! @end
35. NSCoding - (void)storeBook { Book *book = [[Book alloc] init]; book.title = @"The man in the High Castle"; book.pageCount = 288; book.categories = [[NSSet alloc] initWithArray:@[@"Science Fiction", @"Alternate History"]]; ! NSData *data = [NSKeyedArchiver archivedDataWithRootObject:book]; [[NSUserDefaults standardUserDefaults] setObject:data forKey:@"theBook"]; // DON'T DO THIS!! }
36. what’s GEO LOCATION where??
37. CLLocationManager * CCLocationManager Reference “The CLLocationManager class defines the interface for configuring the delivery of location- and heading-related events to your application.”*
38. CLLocationManager •Part of the CoreLocation Framework. •Works with the delegation pattern. •Will ask for user permission.
39. CLLocationManager #import <CoreLocation/CoreLocation.h> ! @interface FooLocation : AController <CLLocationManagerDelegate> @property (nonatomic, strong) CLLocationManager *locationManager; @end ! @implementation FooLocation ! - (instancetype)init { if (self = [super init]) { _locationManager = [[CLLocationManager alloc] init]; _locationManager.delegate = self; _locationManager.distanceFilter = kCLDistanceFilterNone; _locationManager.desiredAccuracy = kCLLocationAccuracyBest; [_locationManager startUpdatingLocation]; } return self; } ! // Delegate Implementation - (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations { CLLocation *lastLocation = [locations lastObject]; CLLocationCoordinate2D lastCoordinate = lastLocation.coordinate; NSLog(@"Last [lat, long] - [%f, %f]", lastCoordinate.latitude, lastCoordinate.longitude); } ! @end
40. what’s XCODE Tools?
41. Xcode Demo & The End :)