NSMutableDictionary won't save data - objective-c

Question

hope someone can help me with a problem I've been wrestling with...
Using MapBox to develop a map-based app, and I want to attach an NSMutableDictionary to each of the map annotations to store additional data. I had it working but XCode kept throwing me warning about some of my data/object types, so I went through and tidied those up, and now it's broken. The idea is that on ViewDidLoad, the program runs through a set of plist dictionaries to set up each annotation correctly - that's still running okay, because my initial anno markers pop up with their correct settings. However rather than run back to the plist every time, I want to attach a dictionary to each annotation's userinfo property, which I can then use for toggling selection data and other functions. Here's my code:
NSDictionary *ExploreSteps = [[NSDictionary alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"ExploreSteps" ofType:#"plist"]];
for (NSString *key in [ExploreSteps allKeys])
{
//Loop through keys for each anno
NSDictionary *thisStep = [ExploreSteps objectForKey:key];
NSNumber *annoIndex = [thisStep objectForKey:#"Index"];
NSNumber *isLive = [thisStep valueForKey:#"isLive"];
NSString *annoTitle = [thisStep objectForKey:#"Title"];
NSString *annoText = [thisStep objectForKey:#"Text"];
NSString *imagefile = [thisStep objectForKey:#"Imagefile"];
double longitude = [[thisStep objectForKey:#"Longitude"] doubleValue];
double latitude = [[thisStep objectForKey:#"Latitude"] doubleValue];
NSString *pagefile = [thisStep objectForKey:#"Pagefile"];
NSString *audiofile = [thisStep objectForKey:#"Audiofile"];
CLLocationCoordinate2D annoCoord = CLLocationCoordinate2DMake(latitude, longitude);
RMAnnotation *annotation = [[RMAnnotation alloc] initWithMapView:mapView coordinate:annoCoord andTitle:annoTitle];
annotation.annotationIcon = [UIImage imageWithContentsOfFile: [[NSBundle mainBundle] pathForResource:imagefile ofType:#"png"]];
annotation.userInfo = [NSMutableDictionary dictionaryWithObjectsAndKeys:annoIndex, #"index", isLive, #"isLive", annoTitle, #"annoTitle", annoText, #"annoText", imagefile, #"imagefile", pagefile, #"pagefile", audiofile, #"audiofile", nil];
NSLog(#"Title: %#",[annotation.userInfo objectForKey:#"annoTitle"]);
[mapView addAnnotation:annotation];
}
The NSLog should spit out the annoTitle string, but instead it's giving me a null every time, and the behaviour of the rest of the app also shows that info stored in the dictionary simply isn't "getting through".
Any ideas? Thanks in advance!
ETA: Modified code for initializing the dictionary (not that it seems to make any difference to the problem!):
NSMutableDictionary *myUserInfo = [[NSMutableDictionary alloc] initWithObjectsAndKeys:annoIndex, #"index", isLive, #"isLive", annoTitle, #"annoTitle", annoText, #"annoText", imagefile, #"imagefile", pagefile, #"pagefile", audiofile, #"audiofile", nil];
annotation.userInfo = myUserInfo;
NSLog(#"Title: %#",[annotation.userInfo objectForKey:#"annoTitle"]);
NSLog(#"Length: %u",[[annotation.userInfo allKeys] count]);
(Title now returns "(null)", while Length returns "1", if that's at all helpful...)

Answer 1

Almost certainly one of your objects is nil. You mention that allKeys] count] returns 1 so I can go further and say that your value for isLive is nil. Hence your original line:
[NSMutableDictionary dictionaryWithObjectsAndKeys:annoIndex, #"index", isLive, #"isLive", annoTitle, #"annoTitle", annoText, #"annoText", imagefile, #"imagefile", pagefile, #"pagefile", audiofile, #"audiofile", nil];
Acts exactly the same as:
[NSMutableDictionary dictionaryWithObjectsAndKeys:annoIndex, #"index", nil, #"isLive", annoTitle, #"annoTitle", annoText, #"annoText", imagefile, #"imagefile", pagefile, #"pagefile", audiofile, #"audiofile", nil];
And the dictionary takes annoIndex to be the final key-value pair.
I'd suggest that probably you want to take a mutable copy of thisStep and strip out the keys you don't want, then pass it along as the userInfo.

Answer 2

It's the way you are creating the NSMutableDictionary for userInfo. Take a look at this Difference between [[NSMutableDictionary alloc] initWithObjects:...] and [NSMutableDictionary dictionaryWithObjects:...]?
"
+dictionaryWithObjects: returns an autoreleased dictionary
-initWithObjects: you must release yourself
if you want the dictionary to persist as a instance variable, you should create it with an init method or retain an autoreleased version, either way you should be sure to release it in your dealloc method
"