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POunrecognized selector from protocol
 

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  1. POunrecognized selector from protocol
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    <p>UPDATE: Issue found, solution found and marked as answer.</p> <p>Issue is that I use a static method of the superclass to initialize, thus turning it into the superclass instead of subclass.</p> <p>END UPDATE:</p> <p>I have a protocol, a class that implements that protocol, and then a class that creates an instance of the protocol'd class that calls the protocol method. I am receiving an "Unrecognized selector sent to instance..." when invoking that protocol method.</p> <p>Note: I am using ArcGIS for displaying a map, but that should be irrelevant to my problem.</p> <p>The protocol method (<code>layerName</code>) works later during runtime on another object that implements LayerProtocol.</p> <p>Example Code:</p> <pre><code>@protocol LayerProtocol &lt;NSObject&gt; - (NSString *) layerName; @end @interface StreetLayer: AGSTiledMapServiceLayer&lt;LayerProtocol&gt; @end @implementation StreetLayer - (id) init { self = [AGSTiledMapServiceLayer tiledMapServiceLayerWithURL: [NSURL URLWithString: [NSString stringWithFormat: @"%@%@", @"https://server.arcgisonline.com/ArcGIS/", @"rest/services/World_Street_Map/MapServer"] ]]; return self; } - (NSString *) layerName { return @"Street Layer"; } @end @interface MapContainerViewController: UIViewController @property (nonatomic) AGSMapView * mapView; @property (nonatomic) StreetLayer * layer; @end @implementation MapContainerViewController - (void) viewDidLoad { _mapView = [[AGSMapView alloc] init]; _layer = [[StreetLayer alloc] init]; [mapView addMapLayer:_layer withName:[_layer layerName]]; } </code></pre> <p>The error occurs on the access to <code>[_layer layerName]</code></p> <p>I feel like I'm missing something really obvious here.</p> <p>I do know that AGSLayer has an access to the name of the layer, that is irrelevant to the problem.</p> <p>Additionally, I have used <code>[_layer respondsToSelector:@selector(layerName)]</code> and it fails that check.</p> <p>STACK TRACE:</p> <p><em>*</em> Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[AGSTiledMapServiceLayer layerName]: unrecognized selector sent to instance 0xbe7ef90'</p> <p><em>*</em> First throw call stack: (</p> <pre><code>0 CoreFoundation 0x035105e4 __exceptionPreprocess + 180 1 libobjc.A.dylib 0x032938b6 objc_exception_throw + 44 2 CoreFoundation 0x035ad903 -[NSObject(NSObject) doesNotRecognizeSelector:] + 275 3 CoreFoundation 0x0350090b ___forwarding___ + 1019 4 CoreFoundation 0x035004ee _CF_forwarding_prep_0 + 14 5 MyProject 0x00061d95 -[MapContainerViewController mapTypeToggled:] + 677 6 libobjc.A.dylib 0x032a5874 -[NSObject performSelector:withObject:withObject:] + 77 7 UIKit 0x01522c8c -[UIApplication sendAction:to:from:forEvent:] + 108 8 UIKit 0x01522c18 -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 61 9 UIKit 0x0161a6d9 -[UIControl sendAction:to:forEvent:] + 66 10 UIKit 0x0161aa9c -[UIControl _sendActionsForEvents:withEvent:] + 577 11 UIKit 0x01619d4b -[UIControl touchesEnded:withEvent:] + 641 12 UIKit 0x015600cd -[UIWindow _sendTouchesForEvent:] + 852 13 UIKit 0x01560d34 -[UIWindow sendEvent:] + 1232 14 UIKit 0x01534a36 -[UIApplication sendEvent:] + 242 15 UIKit 0x0151ed9f _UIApplicationHandleEventQueue + 11421 16 CoreFoundation 0x034998af __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15 17 CoreFoundation 0x0349923b __CFRunLoopDoSources0 + 235 18 CoreFoundation 0x034b630e __CFRunLoopRun + 910 19 CoreFoundation 0x034b5b33 CFRunLoopRunSpecific + 467 20 CoreFoundation 0x034b594b CFRunLoopRunInMode + 123 21 GraphicsServices 0x051d49d7 GSEventRunModal + 192 22 GraphicsServices 0x051d47fe GSEventRun + 104 23 UIKit 0x0152194b UIApplicationMain + 1225 24 GmcSeeds 0x00073b1d main + 141 25 libdyld.dylib 0x03a7f725 start + 0 </code></pre> <p>) libc++abi.dylib: terminating with uncaught exception of type NSException</p> <pre><code>- (void) mapTypeToggled:(id)sender { _streetViewToggled = !_streetViewToggled; if (_streetViewToggled) { // show street view [_mapView removeMapLayer:_satelliteLayer]; [_mapView insertMapLayer:_streetLayer withName:[_streetLayer layerName] atIndex:0]; } else { // show satellite view [_mapView removeMapLayer:_streetLayer]; [_mapView insertMapLayer:_satelliteLayer withName:[_satelliteLayer layerName] atIndex:0]; } } </code></pre>
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    1. COCan you post the stacktrace please.
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    2. COWhat class is receiving the "layerName" message?
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    3. COStack trace posted. I changed the project name and class name to match the question posted. mapTypeToggled: is added to a button that hasn't been clicked yet.
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