gistfile1.m

#import "MyWebViewController.h"
#import "AFNetworking.h"


#if false // facebook

#define LOGIN_URL @"http://sample/login.php?command=facebook&app=true"
#define REDIRECT_URL @"command=facebook_cb"

#else

#define LOGIN_URL @"http://sample/login.php?command=twitter&app=true"
#define REDIRECT_URL @"command=twitter_cb"

#endif

@interface MyWebViewController ()

@property (weak, nonatomic) IBOutlet UIWebView *webView;
@end

@implementation MyWebViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
  // Do any additional setup after loading the view.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void) viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    NSURL *url = [NSURL URLWithString:LOGIN_URL]; // 文字列をURLとして使える形式に変換
    NSURLRequest *req = [NSURLRequest requestWithURL:url]; // URLからリクエストを作る
    [self.webView loadRequest:req]; // Webサーバにリクエスト実施！！
    self.webView.delegate=self;
}

- (void)webViewDidStartLoad:(UIWebView *)webView {
}

-(void) webViewDidFinishLoad:(UIWebView *)webView{
}

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
    NSString *url = [[request URL] absoluteString];
    NSLog(@"%@", url);
    NSRange searchResult = [url rangeOfString:REDIRECT_URL];
    if(searchResult.location == NSNotFound){
        // みつからない場合の処理
        return YES;
    }else{
        UIActivityIndicatorView  *indicator = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
        indicator.frame = CGRectMake(100, 100, 50, 50);
        [self.webView addSubview:indicator];
        [indicator startAnimating];
        indicator.color = [UIColor redColor];
        __weak MyWebViewController *wself = self;
        
        NSURL *nsurl = [NSURL URLWithString:url];
        NSURLRequest *request = [NSURLRequest requestWithURL:nsurl];
        AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request
                                                                                            success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON){
                                                                                                NSLog(@"%@", JSON);
                                                                                                [wself dismissModalViewControllerAnimated:YES];
                                                                                                [indicator removeFromSuperview];
                                                                                            }
                                                                                            failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON){
                                                                                                [wself dismissModalViewControllerAnimated:YES];
                                                                                                [indicator removeFromSuperview];
                                                                                            }];
        NSOperationQueue *queue = [[NSOperationQueue alloc] init] ;
        [queue addOperation:operation];
        
        return NO;
    }
    return YES;
}
@end