How to do Web Service in iOS - Web Service Sample example

Import ApiCall Model object class in ViewController.h

Call delegate APIDelegate in ViewController.h to define the APICall delegate methods in our ViewController View

//=== 

#import <UIKit/UIKit.h>

#import "ViewController.h"

#import "APICall.h"

@interface ViewController ()<APIDelegate>

{

    UILabel * lbl;

}

@end

//=== "ViewController.M"

-(void)viewDidAppear:(BOOL)animated

{

    [super viewDidAppear:animated];

    

    APICall * api= [[APICall alloc] init];

    

    api.del = self;

    

    [api makeAPICallWithMethodName:@"greeting" methodTyep:@"GET" body:nil];

}

-(void)serviceSuccess:(NSData *)data methodName:(NSString *)method

{

    NSLog(@"Data : %@",data);

    NSError *error;

    NSDictionary *jsonDict = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];

    

    NSLog(@"%@", jsonDict);

    

    dispatch_async(dispatch_get_main_queue(), ^{

        lbl.text = [jsonDict objectForKey:@"id"];

    });

}

-(void)serviceError:(NSError *)error methodName:(NSString *)method{

}

//=== All the Magic is in APICall.h model objects to call the service calls

#import <Foundation/Foundation.h>

#define BASEURL @"http://rest-service.guides.spring.io/"

@protocol APIDelegate

@optional

-(void)serviceSuccess:(NSData *)data methodName:(NSString *)method;

-(void)serviceError:(NSError *)error methodName:(NSString *)method;

@end

@interface APICall : NSObject

{

}

@property (strong,nonatomic) id<APIDelegate> del;

-(void)makeAPICallWithMethodName:(NSString *)methodName methodTyep:(NSString *)methodType body:(NSData *)body;

@end

//=== APICAll.M

#import "APICall.h"

@implementation APICall

-(NSMutableURLRequest *)prepareRequestWithMethodName:(NSString *)methodName methodType:(NSString *)methodType body:(NSData *)bodyData

{

    NSDictionary *headers = @{ @"cache-control": @"no-cache",

                               @"postman-token": @"b559e00e-c5a5-e96e-63ea-40907d757a39",@"AUTHTOKEN":@"djajkdhakj" };

    

    NSString * urlString = [NSString stringWithFormat:@"%@%@",BASEURL,methodName];

    

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:urlString]

                                                           cachePolicy:NSURLRequestUseProtocolCachePolicy

                                                       timeoutInterval:10.0];

    [request setHTTPMethod:methodType];

    [request setAllHTTPHeaderFields:headers];

    if ([methodType isEqualToString:@"PUT"] || [methodType isEqualToString:@"POST"]) {

        [request setHTTPBody:bodyData];

    }

    return request;

}

-(void)conncectWithServerRequest:(NSURLRequest *)request methodName:(NSString *)method

{

    NSURLSession *session = [NSURLSession sharedSession];

    NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request

                                                completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {

                                                    if (error) {

                                                        NSLog(@"%@", error);

                                                        [self.del serviceError:error methodName:method];

                                                    } else {

                                                        NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *) response;

                                                        NSLog(@"%@", httpResponse);

                                                        [self.del serviceSuccess:data methodName:method];

                                                    }

                                                }];

    [dataTask resume];

}

-(void)makeAPICallWithMethodName:(NSString *)methodName methodTyep:(NSString *)methodType body:(NSData *)body

{

    NSMutableURLRequest * request = [self prepareRequestWithMethodName:methodName methodType:methodType body:body];

    [self conncectWithServerRequest:request methodName:methodName];

}

@end