![NSString * const SRVR = @"api.example.com";
-(BOOL)reachable
{
Reachability *r = [Reachability reachabilityWithHostName:SRVR];
NetworkStatus internetStatus = [r currentReachabilityStatus];
if(internetStatus == NotReachable) {
return NO;
}
return YES;
}
NotReachable
ReachableViaWifi
ReachableViaWWAN](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-9-320.jpg)
![GET
- (void)makeGetRequest
{
NSURL *url = [NSURL URLWithString:@"http://api.example.com"];
ASIHTTPRequest *request =
[ASIHTTPRequest requestWithURL:url];
[request startSynchronous];
NSError *error = [request error];
if (!error && [request responseStatusCode] == 200)
{
NSString *response = [request responseString];
//NSData *responseData = [request responseData];
}](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-10-320.jpg)
![Errors
else if(error)
NSLog(@"request error: %@",[error localizedDescription]);
else if([request responseStatusCode] != 200)
NSLog(@"server says: %@", [request responseString]);
}](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-11-320.jpg)
![Asynchronous GET
- (void)makeGetRequest
{
NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDelegate:self];
[request startAsynchronous];
}
// DELEGATE METHODS:
- (void)requestFinished:(ASIHTTPRequest *)request
{
NSString *responseString = [request responseString];
}
- (void)requestFailed:(ASIHTTPRequest *)request
{
NSError *error = [request error];
}](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-14-320.jpg)
![Building Blocks
- (void)makeGetRequest
{
NSURL *url = [NSURL URLWithString:@"http://api.example.com"];
__block ASIHTTPRequest *request =
[ASIHTTPRequest requestWithURL:url];
[request setCompletionBlock:^{
NSString *responseString = [request responseString];
}];
[request setFailedBlock:^{
NSError *error = [request error];
}];
[request startAsynchronous];
}](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-16-320.jpg)
![#import "SVProgressHUD.h"
- (void)makeGetRequest
{
NSURL *url = [NSURL URLWithString:@"http://api.example.com"];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[SVProgressHUD showWithStatus:@"Fetching data"];
[request startSynchronous];
if (![request error])
{
" [SVProgressHUD dismissWithSuccess:@"Fetch Successful"];
...
}
else {
" [SVProgressHUD dismissWithError:@"Fetch Failed"];
...
}
}](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-18-320.jpg)
![#import "PullRefreshTableViewController.h"
@interface MyTableViewController : PullRefreshTableViewController
- (void)refresh
{
[self performSelector:@selector(add) withObject:nil afterDelay:2.0];
}
- (void) add
{
...
[self stopLoading];
}
.m
.h](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-22-320.jpg)
![#import "UIImageView+AFNetworking.h"
NSURL *imageURL = [NSURL URLWithString:@”http://example.com/picture.jpg”];
UIImageView *image = [[UIImageView alloc] init];
[image setImageWithURL:imageURL];](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-24-320.jpg)
![ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url];
[request setRequestMethod:@"PUT"]; //REST modify using PUT
[request setPostFormat:ASIMultipartFormDataPostFormat];
// authentication
[request setUsername:username];
[request setPassword:password];
[request setFile:jpgPath forKey:@"image"];
"
[request startSynchronous];](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-26-320.jpg)
![POST & DELETE
[request setRequestMethod:@"POST"];
[request setRequestMethod:@"DELETE"];](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-27-320.jpg)
![Parsing
[request startSynchronous];
...
SBJsonParser *prsr = [[[SBJsonParser alloc] init] autorelease];
// object
NSDictionary *data = [prsr objectWithString:[request responseString]];
// or Array
NSArray *data = [parsr objectWithString:[request responseString]];](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-30-320.jpg)
![INCEPTION
[{[{}]}]
An array of
objects with an
array of objects
[
{
"name":
"object1",
"sub":
[
{
"name":
"subobject1"
},
{
"name":
"subobject2"
}
]
},
]
or rather JCEPTION](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-31-320.jpg)
![NSArray *jArray = [prsr objectWithString:data];
NSDictionary *obj1 = [jArray objectAtIndex:0];
NSString *obj1Name = [obj1 objectForKey:@”name”];
NSArray *obj1SubArray = [obj1 objectForKey:@”sub”];
NSDictionary *subObj1 = [obj1SubArray objectAtIndex:0];
NSNumber *subObj1Val = [subObj1 objectForKey@”value”];
[
{
"name":
"object1",
"sub":
[
{
"name":
"subobject1"
},
{
"value":
1
}
]
},
]
...[[[prsr objectWithSring:data] objectAtIndex:0] objectForKey:@”sub]...](https://image.slidesharecdn.com/developing-ios-rest-applications-170615122436/85/Developing-iOS-REST-Applications-32-320.jpg)
Developing iOS REST Applications
- 2. • WHOAMI • GLAZEDSOLUTIONS.COM • HTML5 Mobile Apps - Friday 15h Main Stage
- 3. • It’s awesome: iPhone, iPad, iPod Touch • Best Mobile App Dev Platform (by light years) • Objective-C + Foundation + Cocoa • Lots of potential users • lots of potentially paying users Why iOS
- 4. • Software architecture for distributed systems • say web services/APIs • Client-Server • Works over HTTP & URI-based • http://api.twitter.com/1/statuses/public_timeline.json REST Quick Intro
- 5. • There’s always something you need in “the cloud” • Data or processing power • More true on mobile • Universal: mobile, desktop, web clients • It’s easy to implement server side ( at least the basic stuff) • and everyone is doing it (twitter, github, amazon, google, ...) • It’s easy to implement on the client Why REST
- 7. iOS REST Recipe Function Library I Use Currently iOS Boilerplate HTTP Requests ASIHTTPRequest AFNetworking JSON SBJson (AKA json-framework) JSONkit Image Caching AFNetworking (I previously used HJCache) AFNetworking Pull-To-Refresh PullToRefreshTableViewController by Leah Culver EGOTableViewPullToRefresh HUD SVProgessHUD (I previously used DSActivityView) SVProgessHUD
- 8. • Am I connected to the internet? • Wifi or Cellular? Reachability (SystemConfiguration framework)
- 9. NSString * const SRVR = @"api.example.com"; -(BOOL)reachable { Reachability *r = [Reachability reachabilityWithHostName:SRVR]; NetworkStatus internetStatus = [r currentReachabilityStatus]; if(internetStatus == NotReachable) { return NO; } return YES; } NotReachable ReachableViaWifi ReachableViaWWAN
- 10. GET - (void)makeGetRequest { NSURL *url = [NSURL URLWithString:@"http://api.example.com"]; ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [request startSynchronous]; NSError *error = [request error]; if (!error && [request responseStatusCode] == 200) { NSString *response = [request responseString]; //NSData *responseData = [request responseData]; }
- 11. Errors else if(error) NSLog(@"request error: %@",[error localizedDescription]); else if([request responseStatusCode] != 200) NSLog(@"server says: %@", [request responseString]); }
- 12. •The app continues to execute •UI continues to be responsive •The request runs in the background •Two (common) ways of doing it in iOS: •Delegate •Block Asynchronous Requests
- 13. • The delegator object has a delegate property that points to the delegate object • A delegate acts when its delegator encounters a certain event • The delegate adopts a protocol • We’ll need 2 methods: success & failure Cocoa Delegate Pattern
- 14. Asynchronous GET - (void)makeGetRequest { NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"]; ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [request setDelegate:self]; [request startAsynchronous]; } // DELEGATE METHODS: - (void)requestFinished:(ASIHTTPRequest *)request { NSString *responseString = [request responseString]; } - (void)requestFailed:(ASIHTTPRequest *)request { NSError *error = [request error]; }
- 15. Cocoa Blocks • Ad hoc function body as an expression • Carry their code & the data they need • ideal for callbacks • We’ll need 2 blocks: success & failure
- 16. Building Blocks - (void)makeGetRequest { NSURL *url = [NSURL URLWithString:@"http://api.example.com"]; __block ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [request setCompletionBlock:^{ NSString *responseString = [request responseString]; }]; [request setFailedBlock:^{ NSError *error = [request error]; }]; [request startAsynchronous]; }
- 17. SVProgressHUD
- 18. #import "SVProgressHUD.h" - (void)makeGetRequest { NSURL *url = [NSURL URLWithString:@"http://api.example.com"]; ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url]; [SVProgressHUD showWithStatus:@"Fetching data"]; [request startSynchronous]; if (![request error]) { " [SVProgressHUD dismissWithSuccess:@"Fetch Successful"]; ... } else { " [SVProgressHUD dismissWithError:@"Fetch Failed"]; ... } }
- 19. Where to Load Data • viewDidLoad / viewWillAppear • Make the asynchronous request • Show HUD or other “loading” indicators • LOADED = NO; • Delegate • LOADED = YES; • Reload table • Partial Load + Pagination • Load more at the end of the table
- 20. PullToRefresh
- 22. #import "PullRefreshTableViewController.h" @interface MyTableViewController : PullRefreshTableViewController - (void)refresh { [self performSelector:@selector(add) withObject:nil afterDelay:2.0]; } - (void) add { ... [self stopLoading]; } .m .h
- 23. Background Loading & Caching Images
- 24. #import "UIImageView+AFNetworking.h" NSURL *imageURL = [NSURL URLWithString:@”http://example.com/picture.jpg”]; UIImageView *image = [[UIImageView alloc] init]; [image setImageWithURL:imageURL];
- 25. Updating My Profile Picture •Modify an existing record •Authenticate •Upload a file
- 26. ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url]; [request setRequestMethod:@"PUT"]; //REST modify using PUT [request setPostFormat:ASIMultipartFormDataPostFormat]; // authentication [request setUsername:username]; [request setPassword:password]; [request setFile:jpgPath forKey:@"image"]; " [request startSynchronous];
- 27. POST & DELETE [request setRequestMethod:@"POST"]; [request setRequestMethod:@"DELETE"];
- 28. I JSON (because it’s not XML) JSON OBJECTIVE-C/FOUNDATION Object NSDictionary Array NSArray String NSString Number NSNumber Boolean NSNumber (0 or 1)
- 29. 1. Download a JSON string (via an http request) 2.Convert it to native data structures (parsing) 3.Use the native data structures
- 30. Parsing [request startSynchronous]; ... SBJsonParser *prsr = [[[SBJsonParser alloc] init] autorelease]; // object NSDictionary *data = [prsr objectWithString:[request responseString]]; // or Array NSArray *data = [parsr objectWithString:[request responseString]];
- 31. INCEPTION [{[{}]}] An array of objects with an array of objects [ { "name": "object1", "sub": [ { "name": "subobject1" }, { "name": "subobject2" } ] }, ] or rather JCEPTION
- 32. NSArray *jArray = [prsr objectWithString:data]; NSDictionary *obj1 = [jArray objectAtIndex:0]; NSString *obj1Name = [obj1 objectForKey:@”name”]; NSArray *obj1SubArray = [obj1 objectForKey:@”sub”]; NSDictionary *subObj1 = [obj1SubArray objectAtIndex:0]; NSNumber *subObj1Val = [subObj1 objectForKey@”value”]; [ { "name": "object1", "sub": [ { "name": "subobject1" }, { "value": 1 } ] }, ] ...[[[prsr objectWithSring:data] objectAtIndex:0] objectForKey:@”sub]...