NSXMLParser terminating due to NSUnknownKeyException - ios

Question

I am having trouble parsing an XML document to my project. I am getting the following error:
Terminating app due to uncaught exception 'NSUnknownKeyException',
reason: '[ setValue:forUndefinedKey:]: this class is
not key value coding-compliant for the key morph.'
Here is a snippet of my XML document:
<?xml version="1.0" encoding="utf-8"?>
<CAS version="2.1" avatar="anna">
<frames count="111" signCount="3">
<signStart index="0" gloss="mug" />
<frame index="0" isComplete="true" time="0" duration="20" boneCount="74"
morphCount="51">
<morph name="aaa" amount="0" />
<morph name="ooo" amount="0" />
<morph name="pout" amount="0" />
<morph name="eee" amount="0" />
<morph name="cgng" amount="0" />
Here is my code in my XMLParser.h file:
#import <Foundation/Foundation.h>
#class User;
#interface XMLParser : NSObject {
// an ad hoc string to hold element value
NSMutableString *currentElementValue;
// user object
User *user;
// array of user objects
NSMutableArray *times;
NSMutableArray *durations;
NSMutableArray *wheres;
}
#property (nonatomic, retain) User *user;
#property (nonatomic, retain) NSMutableArray *times;
#property (nonatomic, retain) NSMutableArray *durations;
#property (nonatomic, retain) NSMutableArray *wheres;
- (XMLParser *) initXMLParser;
#end
and XMLParser.m
#import "XMLParser.h"
#import "User.h"
#implementation XMLParser
#synthesize user, times, durations, wheres;
- (XMLParser *) initXMLParser {
self = [super init];
if(self){
// init array of user objects
times = [[NSMutableArray alloc] init];
durations = [[NSMutableArray alloc] init];
// wheres = [[NSMutableArray alloc] init];
}
return self;
}
- (void)parser:(NSXMLParser *)parser
didStartElement:(NSString *)elementName
namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qualifiedName
attributes:(NSDictionary *)attributeDict {
if(![elementName isEqual:#"frame"])
return;
NSLog(#"user element found – create a new instance of User class...");
user = [[User alloc] init];
//We do not have any attributes in the user elements, but if
// you do, you can extract them here:
NSString *time = [attributeDict objectForKey:#"time"];
NSString *duration = [attributeDict objectForKey:#"duration"];
//NSString *where = [attributeDict objectForKey:#"where"];
[times addObject:time];
[durations addObject:duration];
// [wheres addObject:where];
}
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {
if (!currentElementValue) {
// init the ad hoc string with the value
currentElementValue = [[NSMutableString alloc] initWithString:string];
} else {
// append value to the ad hoc string
[currentElementValue appendString:string];
}
NSLog(#"Processing value for : %#", string);
}
- (void)parser:(NSXMLParser *)parser
didEndElement:(NSString *)elementName
namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qName {
if ([elementName isEqualToString:#"CAS"]) {
// We reached the end of the XML document
NSLog(#"names array: %#", times);
NSLog(#"prices array: %#", durations);
// NSLog(#"wheres array: %#", wheres);
return;
}
if ([elementName isEqualToString:#"frame"]) {
// We are done with user entry – add the parsed user
// object to our user array
//[users addObject:user];
//user = nil;
} else {
// The parser hit one of the element values.
// This syntax is possible because User object
// property names match the XML user element names
[user setValue:currentElementValue forKey:elementName];
}
currentElementValue = nil;
}
I assume it has something to do with my xml file, but am not 100% on the exact problem.
Any help would be much appreciated.
Cheers,
Sam

Answer 1

Offhand it looks like your User object doesn't actually have a property called 'morph'. Double check that you spelled it properly, and it's actually the right class at runtime.

Answer 2

Does your user class implement KVO for the key "morph"?
What your User class needs to have to be considered KVC
Can you post the interface and implementation of your User class? That would be handy.
More about implementing KVO

Answer 3

I discovered the problem was due to this line of code:
[user setValue:currentElementValue forKey:elementName];
I have temporarily removed it from my code until I understand why it is make the program throw an exception