Consuming web service with RESTKIT - ios

Question

I am a beginner to RESTKIT and have only just recently tested it out on foursquare public api from ray's tutorial http://www.raywenderlich.com/13097/intro-to-restkit-tutorial.
Although i get the gist of it, there are some part which i do not understand, and would like pointer for it, so that i can consume my own web service.
- (void)viewDidLoad
{
[super viewDidLoad];
RKURL *baseURL = [RKURL URLWithBaseURLString:#"https://api.Foursquare.com/v2"];
RKObjectManager *objectManager = [RKObjectManager objectManagerWithBaseURL:baseURL];
objectManager.client.baseURL = baseURL;
RKObjectMapping *venueMapping = [RKObjectMapping mappingForClass:[Venue class]];
[venueMapping mapKeyPathsToAttributes:#"name", #"name", nil];
[objectManager.mappingProvider setMapping:venueMapping forKeyPath:#"response.venues"];
[self sendRequest];
}
how do I change
[venueMapping mapKeyPathsToAttributes:#"name", #"name", nil];
[objectManager.mappingProvider setMapping:venueMapping forKeyPath:#"response.venues"];
to accommodate my own webMethod? (my webMethod is shown below)
Currently, I upload my file to IIS for testing purpose, and am using the IP for web service. (I am constantly changing work area, so I designate it as myIPAddress for easier communication)
-- My service code (changed EDIT:now return JSON)
[WebMethod]
[ScriptMethod( ResponseFormat = ResponseFormat.Json)]
public void testTextJSON()
{
string text = "Testing for Json!";
List<string> arrayList = new List<string>();
arrayList.Add(text);
JavaScriptSerializer js = new JavaScriptSerializer();
string name = js.Serialize(arrayList);
Context.Response.Write(name);
}
return - ["Testing for Json!"]
EDIT- what I changed currently for viewDidLoad and sendRequest to test for my own service
- (void)viewDidLoad
{
[super viewDidLoad];
RKURL *baseURL = [RKURL URLWithBaseURLString:#"http://192.168.1.12"];
RKObjectManager *objectManager = [RKObjectManager objectManagerWithBaseURL:baseURL];
objectManager.client.baseURL = baseURL;
RKObjectMapping *venueMapping = [RKObjectMapping mappingForClass:[venue class]];
[venueMapping mapKeyPathsToAttributes:#"name", #"name", nil];
[self sendRequest];
}
and
- (void)sendRequest
{
RKObjectManager *objectManager = [RKObjectManager sharedManager];
RKURL *URL = [RKURL URLWithBaseURL:[objectManager baseURL] resourcePath:#"/webService/webService1.asmx/testTextJSON"];
objectManager.acceptMIMEType = RKMIMETypeJSON;
objectManager.serializationMIMEType = RKMIMETypeJSON;
[[RKParserRegistry sharedRegistry] setParserClass:[RKJSONParserJSONKit class] forMIMEType:#"text/plain"];
[objectManager loadObjectsAtResourcePath:[NSString stringWithFormat:#"%#", [URL resourcePath]] delegate:self];
}
EDIT n+1 - here are some of my error message, maybe someone can tell me what went wrong?
2012-11-25 06:49:20.925 fourSquareAPI[352:12e03] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<__NSCFString 0x8354430> valueForUndefinedKey:]: this class is not key value coding-compliant for the key venues.'
If I remove [objectManager.mappingProvider setMapping:venueMapping forKeyPath:#"venues"];
I would get
2012-11-25 06:52:47.495 fourSquareAPI[368:11603] response code: 200
2012-11-25 06:52:47.499 fourSquareAPI[368:12e03] W restkit.object_mapping:RKObjectMapper.m:87 Adding mapping error: Could not find an object mapping for keyPath: ''
2012-11-25 06:52:47.499 fourSquareAPI[368:12e03] E restkit.network:RKObjectLoader.m:231 Encountered errors during mapping: Could not find an object mapping for keyPath: ''
2012-11-25 06:52:47.502 fourSquareAPI[368:11603] Error: Could not find an object mapping for keyPath: ''
Can someone please teach me what to do?? Any help would be greatly appreciated, I would really like to learn how to use RESTKIT to consume a webservice.

Answer 1

The key path response.venues is a path to the attribute with respect to the server response that is in JSON or XML format. In this case, the server returns "response" which has the key "venues". This is most likely a list of venues that you would apply the mapping to. You have to adapt that based on your server response.
If you want to handle a specific value before the mapping, use this function:
- (void)objectLoader:(RKObjectLoader *)loader willMapData:(inout __autoreleasing id *)mappableData; {
if([*mappableData valueForKey:#"result"] != nil){
[*mappableData removeObjectForKey:#"result"]; //This key won't be mapped now
}
}