Getting Restkit tutorial code to work

Question

I am relatively new to development on iOS and trying to get familiarized with RestKit, so bear with me if I am missing something obvious.

We are developing an iOS 5 application that will receive and map JSON to objects (ARC is enabled, if it matters). In search of a tutorial for Restkit, I came across this one. However, a simplified version of the sample code there (the one in the "A real life example with RKClient" section) fails with the following error:

2012-01-14 22:15:55.124 Test_StaticLibInApp[789:707] *** Assertion failure in -[RKRequestQueue removeRequest:decrementCounter:], /Users/m/Documents/devel/ios/RestKit/Code/Network/RKRequestQueue.m:350
2012-01-14 22:15:55.129 Test_StaticLibInApp[789:707] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Attempted to decrement loading count below zero'

To be exact, here's the code I have tried:

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    RKClient *client = [RKClient clientWithBaseURL:@"some_url"];
    RKLogConfigureByName("RestKit/Network", RKLogLevelTrace);

    NSDictionary *queryParameters = [NSDictionary dictionaryWithObjectsAndKeys:nil];
    NSString *getResourcePath = RKPathAppendQueryParams(@"some_url_segment", queryParameters);
    RKRequest *request = [client get:getResourcePath delegate:self];
    [request sendAsynchronously];
}

- (void)request:(RKRequest *)request didLoadResponse:(RKResponse *)response
{
    id jsonParser = [[RKParserRegistry sharedRegistry] parserForMIMEType:RKMIMETypeJSON];
    NSError *error = nil;
    id parsedResponse = [jsonParser objectFromString:[response bodyAsString] error:&error];
    if (error == nil)
    {
        NSLog(@"GET returned with HTTP Code %d and parsedContent: %@", [response statusCode], parsedResponse);
    }
    else
    {
        NSLog(@"Error: %@", error);
    }
}

- (void)request:(RKRequest *)request didFailLoadWithError:(NSError *)error
{
    NSLog(@"Failure of GET with error %@.", error);
}

Here's the trace output:

2012-01-14 22:15:54.746 Test_StaticLibInApp[789:707] I restkit:RKLog.m:30 RestKit initialized...
2012-01-14 22:15:54.765 Test_StaticLibInApp[789:707] D restkit.network:RKRequest.m:365 Sending asynchronous GET request to URL <url>.
2012-01-14 22:15:54.771 Test_StaticLibInApp[789:707] T restkit.network:RKRequest.m:313 Prepared GET URLRequest '<NSMutableURLRequest url>'. HTTP Headers: {
    "Content-Length" = 0;
}. HTTP Body: .
2012-01-14 22:15:54.852 Test_StaticLibInApp[789:707] I restkit.network.reachability:RKReachabilityObserver.m:369 Network availability has been determined for reachability observer <RKReachabilityObserver: 0x15c920 host=<server ip> isReachabilityDetermined=YES isMonitoringLocalWiFi=448340 reachabilityFlags=-R ------d>
2012-01-14 22:15:54.857 Test_StaticLibInApp[789:707] D restkit.network:RKClient.m:388 Reachability to host '<server ip>' determined for client <RKClient: 0x158740>, unsuspending queue <RKRequestQueue: 0x15b260 name=(null) suspended=YES requestCount=1 loadingCount=0/5>
2012-01-14 22:15:55.037 Test_StaticLibInApp[789:707] D restkit.network:RKResponse.m:189 NSHTTPURLResponse Status Code: 200
2012-01-14 22:15:55.044 Test_StaticLibInApp[789:707] D restkit.network:RKResponse.m:190 Headers: {
    "Content-Type" = "application/json";
    Date = "Sat, 14 Jan 2012 20:16:21 GMT";
    Server = "Apache-Coyote/1.1";
    "Transfer-Encoding" = Identity;
}
2012-01-14 22:15:55.048 Test_StaticLibInApp[789:707] T restkit.network:RKResponse.m:195 Read response body: <json text here>
2012-01-14 22:15:55.059 Test_StaticLibInApp[789:707] I restkit.network:RKRequest.m:565 Status Code: 200
2012-01-14 22:15:55.066 Test_StaticLibInApp[789:707] D restkit.network:RKRequest.m:566 Body: <json text here>
2012-01-14 22:15:55.106 Test_StaticLibInApp[789:707] GET returned with HTTP Code 200 and parsedContent: <json text here>
2012-01-14 22:15:55.124 Test_StaticLibInApp[789:707] *** Assertion failure in -[RKRequestQueue removeRequest:decrementCounter:], /Users/m/Documents/devel/ios/RestKit/Code/Network/RKRequestQueue.m:350
2012-01-14 22:15:55.129 Test_StaticLibInApp[789:707] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Attempted to decrement loading count below zero'
*** First throw call stack:
(0x33fac8bf 0x341fc1e5 0x33fac7b9 0x3595b3b3 0x1da7f 0x1e7a3 0x3598150f 0x33f78577 0x33f040cf 0x358f53fb 0x1818b 0x2064b 0x359b8c39 0x359106e9 0x359106b3 0x359105d5 0x31fbe8a5 0x31fb3545 0x31fb3243 0x31fb3179 0x33f80b03 0x33f802cf 0x33f7f075 0x33f024dd 0x33f023a5 0x30786fcd 0x37383743 0x2c81 0x2c18)

Is this error somehow related to the application being compiled with ARC? For Restkit installation, I got the files from the git master branch and followed the installation instructions, not changing any of its settings.

Thanks in advance for any help.

Answer 1

RestKit should not be compiled with ARC enabled. What I do is compile RestKit for Simulator and Device and then add the resulting .a and includes in my ARC enabled project. Also, did you add -all_load -ObjC to Other Linker Flags? Regards,

Answer 2

the line

[request sendAsynchronously]

is not needed.

[client get:getResourcePath delegate:self]

already sends the request, and decrements the request count. you are getting

reason: 'Attempted to decrement loading count below zero'

because of this.