Improved error reporting on loading gestures.

GLGestureRecognizer/GLGestureRecognizer+JSONTemplates.h

@@ -12,6 +12,6 @@
 
 @interface GLGestureRecognizer (JSONTemplates)
 
-- (BOOL)loadTemplatesFromJsonData:(NSData *)jsonData;
+- (BOOL)loadTemplatesFromJsonData:(NSData *)jsonData error:(NSError **)errorOut;
 
 @end

GLGestureRecognizer/GLGestureRecognizer+JSONTemplates.m

@@ -10,15 +10,17 @@
 
 @implementation GLGestureRecognizer (JSONTemplates)
 
-- (BOOL)loadTemplatesFromJsonData:(NSData *)jsonData
+- (BOOL)loadTemplatesFromJsonData:(NSData *)jsonData error:(NSError **)errorOut
 {
 	// The recognized gestures are loaded from JSON format, using the TouchJSON library.
 	// As an example, if kSamplePoints were 3, here is an example file with one gesture:
 	//   { "line" : [ [1.0, 0.0], [0.0, 0.0], [-1.0, 0.0] ] }
 	// (A dictionary with string key names and an array of 2-element array coordinate pairs.)
 	// To populate the file, use the output of the NSLog()s in findBestMatch..: after drawing a shape.
-	NSError *error = nil;
-	NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:&error];
+	NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:errorOut];
+	if (!dict)
+		return NO;
+
 	NSMutableDictionary *output = [NSMutableDictionary dictionary];
 	[dict enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSArray *value, BOOL *stop) {
 		NSMutableArray *points = [NSMutableArray arrayWithCapacity:value.count];

GesturesDemo/GestureView.m

@@ -35,7 +35,16 @@ - (void)awakeFromNib
 {
 	recognizer = [[GLGestureRecognizer alloc] init];
 	NSData *jsonData = [NSData dataWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"Gestures" ofType:@"json"]];
-	[recognizer loadTemplatesFromJsonData:jsonData];
+
+	BOOL ok;
+	NSError *error;
+	ok = [recognizer loadTemplatesFromJsonData:jsonData error:&error];
+	if (!ok)
+	{
+		NSLog(@"Error loading gestures: %@", error);
+		self.caption = @"Error loading gestures.";
+		return;
+	}
 
 	self.caption = @"";
 }