Restkit basic url response - ios

Question

I am learning Rest-kit. i am trying to parse this url https://api.coursera.org/api/catalog.v1/courses?fields=language,shortDescription
I have created one Courses class.
#interface Courses : NSObject
#property (nonatomic, strong) NSString *name;
#end
and in viewcontroller i have wrote below code
- (void)viewDidLoad
{
[super viewDidLoad];
[self configureRestKit];
[self loadCourses];
}
- (void)configureRestKit
{
// https://api.coursera.org/api/catalog.v1/courses?fields=language,shortDescription
// initialize AFNetworking HTTPClient
NSURL *baseURL = [NSURL URLWithString:#"https://api.coursera.org"];
AFHTTPClient *client = [[AFHTTPClient alloc] initWithBaseURL:baseURL];
// initialize RestKit
RKObjectManager *objectManager = [[RKObjectManager alloc] initWithHTTPClient:client];
// setup object mappings
RKObjectMapping *courseMapping = [RKObjectMapping mappingForClass:[Courses class]];
[courseMapping addAttributeMappingsFromDictionary:#{
#"name":#"name"
}];
// register mappings with the provider using a response descriptor
RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:courseMapping method:RKRequestMethodGET pathPattern:#"/api/catalog.v1/courses?fields=language,shortDescription" keyPath:#"elements" statusCodes:[NSIndexSet indexSetWithIndex:200]];
[objectManager addResponseDescriptor:responseDescriptor];
}
- (void)loadCourses
{
[[RKObjectManager sharedManager] getObjectsAtPath:#"/api/catalog.v1/courses?fields=language,shortDescription" parameters:nil success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
NSLog(#"%#", mappingResult.array);
} failure:^(RKObjectRequestOperation *operation, NSError *error) {
NSLog(#"What do you mean by 'there is no Courses?': %#", error);
}];
}
ERROR :_Error Domain=org.restkit.RestKit.ErrorDomain Code=1001 "No response descriptors match the response loaded."
I am not getting response in success block. Please correct me. Thanks in advance

Answer 1

Don't add your query parameters to the path pattern on the response descriptor, and set them as parameters on the request:
pathPattern:#"/api/catalog.v1/courses"
generally I would also say that /api/catalog.v1/ should be part of the base URL so you would have:
NSURL *baseURL = [NSURL URLWithString:#"https://api.coursera.org/api/catalog.v1/"];
...
... pathPattern:#"courses" ...
...
... getObjectsAtPath:#"courses" parameters:#{ #"fields" : #"language,shortDescription" } ...