RestKit Best practices with the sendSynchronously method - restkit

Question

I am trying to load objects synchronously with RestKit and to do that I am using [anObjectLoader sendSynchronously] on a background thread. Then in the RKObjectLoader didFinishLoad: the application is currently stopping at the first line: NSAssert([NSThread isMainThread], #"RKObjectLoaderDelegate callbacks must occur on the main thread");
Looking at the documentation, the sendSynchronously method from the RKRequest class says that the request will be synchronously requested and a hydrated response object will be returned.
This is a snapshot of my code:
RKObjectLoader *anObjectLoader = [self.objectManager loaderWithResourcePath:resourcePath];
NSLog(#"Response: %#", [anObjectLoader sendSynchronously]);
On console:
*** Assertion failure in -[RKManagedObjectLoader didFinishLoad:], ...RestKit/Code/ObjectMapping/RKObjectLoader.m:423
Is it Ok to use RestKit with synchronous calls?
Are there better ways to send synchronous requests?
Am I missing something?

Answer 1

You should never make synchronous calls. Use the send method and catch the response using either delegates or block callbacks. Among other things, this method is optimized for network bandwidth usage and also handles threading correctly.
As an aside, the reason RKObjectLoader requires the main thread is because that is where your main object context is.

Answer 2

I recently had this same question. I figured out how to send a synchronous call using blocks and it's actually quite nice. Basically you do whatever restkit call you were intending to do, but instead of setting the delegate to self, you use usingBlock. Then, within that block you can handle the various responses from your API call.
Block Example (APIUser is class I wrote that represents the current user):
[[RKObjectManager sharedManager] loadObjectsAtResourcePath:[#"/api/users/" stringByAppendingString:userName] usingBlock:^(RKObjectLoader* loader) {
loader.onDidLoadResponse = ^(RKResponse *response) {
NSLog(#"Response: \n%#", [response bodyAsString]);
};
loader.onDidLoadObjects = ^(NSArray *objects) {
APIUser *apiUser = [objects objectAtIndex:0];
};
loader.onDidFailWithError = ^(NSError *error) {
NSLog(#"Response: \n%#", [response bodyAsString]);
};
}];
My original question and answer can be found here.