1. iOS REST Client
Paul Lynch
@pauldlynch, paul@plsys.co.uk

2. • Architecture of iOS apps
• Comet Architecture
• Model Implementation
• Controller Implementation
• Other iOS Concepts
iOS REST Client

3. Architecture of iOS apps
• MVC - Model/View/Controller
• Objective C
• Foundation
• UIKit - UIApplication, UIViewController, UIView, UIControl

4. Foundation
• NSArray, NSDictionary, NSSet
• NSValue
• NSPredicate

5. UIKit - UIApplication
• UIApplication
• status bar
• window
• orientation
• AppDelegate
applicationDidFinishLaunchingWithOptions:
notifications - UIApplicationWillEnterForegroundNotification,
UIApplicationDidEnterBackgroundNotification

6. UIView
• animations
• gestures

7. View Controllers
• - (id)initWithNibName:(NSString *)nibName bundle:(NSBundle *)nibBundle
• navigationController, tabBarController
• rotation, transitions
• subclasses - e.g. UITableViewController

8. TableViews
• UITableViewController
• UITableView
• data source
• delegate
• UITableViewCell

9. Table view data source
@protocol UITableViewDataSource<NSObject>
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section;
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath;
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView;
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section;
- (NSString *)tableView:(UITableView *)tableView titleForFooterInSection:(NSInteger)section;
...
@end
@interface NSIndexPath (UITableView)
+ (NSIndexPath *)indexPathForRow:(NSInteger)row inSection:(NSInteger)section;
@property(nonatomic,readonly) NSInteger section;
@property(nonatomic,readonly) NSInteger row;
@end

10. Table view delegate
@protocol UITableViewDelegate<NSObject, UIScrollViewDelegate>
...
- (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath;
...
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath;
...
@end

11. Comet Architecture

12. Comet Architecture
Marketing
db
Reviews
WO db
XML
Linux, mySQL
Change
Report
Mobile
clients

13. Comet Database
Features: skunum, runId; xml/json held as strings
Category
SKU
Review WC7SKU
Client

14. REST API
• category - parent, children
• sku
• skudetail - contains full review and XML text
• brand - attribute of sku

15. ERREST Routes
routeRequestHandler.addRoute(new ERXRoute(Sku.ENTITY_NAME, "/sku", ERXRoute.Method.Options, SkuController.class,
"options"));
routeRequestHandler.addRoute(new ERXRoute(Sku.ENTITY_NAME, "/sku", ERXRoute.Method.Head, SkuController.class, "head"));
routeRequestHandler.addRoute(new ERXRoute(Sku.ENTITY_NAME, "/sku", ERXRoute.Method.All, SkuController.class, "index"));
// MS: this only works with numeric ids
routeRequestHandler.addRoute(new ERXRoute(Sku.ENTITY_NAME, "/sku/{action:identifier}", ERXRoute.Method.Get, SkuController.class));
routeRequestHandler.addRoute(new ERXRoute(Sku.ENTITY_NAME, "/sku/{sku:Sku}", ERXRoute.Method.Get, SkuController.class, "show"));
routeRequestHandler.addRoute(new ERXRoute(Sku.ENTITY_NAME, "/sku/{sku:Sku}/{action:identifier}", ERXRoute.Method.All,
SkuController.class));
plus Category, Brand, Skudetail

16. Model Implementation
• PLRestful
• CometAPI
• Sku (etc)

17. PLRestful
typedef void (^PLRestfulAPICompletionBlock)(PLRestful *api, id object, NSInteger status, NSError *error);
@interface PLRestful : NSObject
@property (nonatomic, copy) NSString *endpoint;
@property (nonatomic, copy) PLRestfulAPICompletionBlock completionBlock;
@property (nonatomic, copy) NSString *username;
@property (nonatomic, copy) NSString *password;
@property (nonatomic, assign) BOOL useBasicAuthentication;
+ (NSString *)messageForStatus:(NSInteger)status;
+ (BOOL)checkReachability:(NSURL *)url;
+ (void)get:(NSString *)requestPath parameters:(NSDictionary *)parameters completionBlock:(PLRestfulAPICompletionBlock)completion;
+ (void)post:(NSString *)requestPath content:(NSDictionary *)content completionBlock:(PLRestfulAPICompletionBlock)completion;
- (void)get:(NSString *)requestPath parameters:(NSDictionary *)parameters completionBlock:(PLRestfulAPICompletionBlock)completion;
- (void)post:(NSString *)requestPath content:(NSDictionary *)content completionBlock:(PLRestfulAPICompletionBlock)completion;
@end

18. PLRestful - get
- (void)get:(NSString *)requestString parameters:(NSDictionary *)parameters completionBlock:
(PLRestfulAPICompletionBlock)completion {
NSURL *requestURL = [[NSURL URLWithString:endpoint] urlByAddingPath:requestString parameters:parameters];
NSLog(@"get: '%@'", [requestURL absoluteString]);
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:requestURL];
[request setHTTPMethod:@"GET"];
[self handleRequest:request completion:(PLRestfulAPICompletionBlock)completion];
}

19. PLRestful - post
- (void)post:(NSString *)requestString content:(NSDictionary *)content completionBlock:(PLRestfulAPICompletionBlock)completion {
NSURL *requestURL = [[NSURL URLWithString:endpoint] urlByAddingPath:requestString parameters:nil];
NSLog(@"post: '%@'", [requestURL absoluteString]);
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:requestURL];
[request setHTTPMethod:@"POST"];
NSError *error = nil;
request.HTTPBody = [NSJSONSerialization dataWithJSONObject:content options:0 error:&error];
if (error) {
NSLog(@"json generation failed: %@", error);
[self callCompletionBlockWithObject:nil status:0 error:[NSError errorWithDomain:@"com.plsys.semaphore.CometAPI" code:1003 userInfo:nil]];
return;
}
[self handleRequest:request completion:completion];
}

20. Controller Implementation
• SkuController
• subclass of UITableViewController

21. SkuController - data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [skus count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSDictionary *sku = [skus objectAtIndex:indexPath.row];
static NSString *CellIdentifier = @"SkuCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
cell.accessoryType = UITableViewCellAccessoryDetailDisclosureButton;
}
// Configure the cell...
cell.textLabel.text = [[sku valueForKey:@"productName"] pl_stringByStrippingHTML];
cell.detailTextLabel.text = [sku valueForKey:@"skuNum"];
id image = [images objectAtIndex:indexPath.row];
if ([image isKindOfClass:[UIImage class]]) {
cell.imageView.image = image;
}
return cell;
}

22. SkuController - tv delegate
- (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath {
NSDictionary *sku = [skus objectAtIndex:indexPath.row];
NSString *skuNum = [[sku valueForKey:@"skuNum"] copy];
NSLog(@"tapped: %@", skuNum);
SkuDetail *view = [[SkuDetail alloc] initWithStyle:UITableViewStylePlain];
view.sku = sku;
view.image = [images objectAtIndex:indexPath.row];
[self.navigationController pushViewController:view animated:YES];
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self tableView:tableView accessoryButtonTappedForRowWithIndexPath:indexPath];
}
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row == ((batch + 1)*25)-1) {
// time to fetch more
self.batch = ++batch;
NSMutableDictionary *batchParameters = [parameters mutableCopy];
if (!batchParameters) batchParameters = [NSMutableDictionary dictionary];
[batchParameters setObject:[NSNumber numberWithInt:batch] forKey:@"batch"];
NSLog(@"batchParameters %@", batchParameters);
[CometAPI get:query parameters:batchParameters completionBlock:^(PLRestful *api, id object, NSInteger status, NSError *error) {
if (error) [self handleError:error];
else {
[self didAddSkus:object];
}
}];
}
}

23. Other iOS Topics
• Human Interface Guidelines
• Buttons - 44x44
• Gestures
• Controllers - mail, movie, picker
• Other UIControls - switch, slider, page control
• iOS 7

24. Code Example
• SOE Status
• http://github.com/pauldlynch/SOEStatus
• older version, will update soon

25. Q&A
Paul Lynch
paul@plsys.co.uk
@pauldlynch