NSUnknownKeyException - setValue: forUndefinedKey in classfile

Question

I am pretty new to iPhone development and I am getting this error output. I know what is happening, I just don't know how to fix it.

 Terminating app due to uncaught exception 'NSUnknownKeyException', reason: 
'[<loginData 0x6b1c> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key UserEMailAddress.'

Basically I am using the XML parser and trying to store data into my created class 'loginData.' The first element I come to, is UserEMailAddress and the code is trying to store that value into the class variable UserEMailAddress of the same name. But its throwing that error.

Obviously something went awry when I created my class. Somehow I guess things were not set up right and it can't input the data into the class. All I did to create loginData was do a file->new-> class object.

Here is the class code.

loginData.h

#import <Foundation/Foundation.h>

@interface loginData : NSObject{
  NSString *UserEMailAddress;
  NSString *SessionUID;
  NSString *SessionExpirationUTCDT;

 }

@property (nonatomic, retain) NSString *UserEMailAddress;
@property (nonatomic, retain) NSString *SessionUID;
@property (nonatomic, retain) NSString *SessionExpirationUTCDT;

@end

loginData.m

  #import "loginData.h"

  @implementation loginData

  @synthesize UserEMailAddress=_UserEMailAddress;
  @synthesize SessionUID=_SessionUID;
  @synthesize SessionExpirationUTCDT=_SessionExpirationUTCDT;

  @end

pretty simple stuff, nothing too complex.

the last method accessed before the crash is in my XMLParser, which is..

- (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);
  } 

I'm sure I just made a small mistake in making my class, but I don't know what that would be. Thanks in advance.

The only other method where it looks as if the variables are input to my class is this one.

  - (void)parser:(NSXMLParser *)parser 
   didEndElement:(NSString *)elementName
   namespaceURI:(NSString *)namespaceURI 
   qualifiedName:(NSString *)qName {

   if ([elementName isEqualToString:@"LoginResponse"]) {
       // We reached the end of the XML document
       return;
   }

  //if ([elementName isEqualToString:@"user"]) {
      // We are done with user entry – add the parsed user 
      // object to our user array
      //[users addObject:user];
      // release user object
      //[user release];
      //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   
      [loginData setValue:currentElementValue forKey:elementName];
  }   

  currentElementValue = nil;
}

Answer 1

Lets look at your code:

loginData.h

@interface loginData : NSObject{
  NSString *UserEMailAddress;
  ...
 }

@property (nonatomic, retain) NSString *UserEMailAddress;
...

@end

loginData.m

@implementation loginData

@synthesize UserEMailAddress=_UserEMailAddress;
...

@end

If you notice, you synthesize the property to a missing variable name, _UserEMailAddress. you should replace that with UserEMailAddress, and your code will work fine.

Answer 2

I was facing the same issue because I renamed a attribute manually starting from a header - *.h - file. It look like by doing this, somewhere the manually renamed attribute remains referenced with the original name.

In order to fix this, I renamed back the attribute to the original name and them started a rename from source file - *.m.

Answer 3

I managed to solve it as I use the same example. What I did is use the names in the xml as my variables in my XMLParser.h For example, if your XML File is like that:

<Foo>
 <Param1>
  <UserEMailAddress>foo</UserEMailAddress>
  <SessionUID>foo</SessionUID>
  <SessionExpirationUTCDT>foo</SessionExpirationUTCDT>
 </Param1>
</Foo>

Your loginData.h will stay:

#import <Foundation/Foundation.h>

@interface loginData : NSObject{
  NSString *UserEMailAddress;
  NSString *SessionUID;
  NSString *SessionExpirationUTCDT;

 }

@property (nonatomic, retain) NSString *UserEMailAddress;
@property (nonatomic, retain) NSString *SessionUID;
@property (nonatomic, retain) NSString *SessionExpirationUTCDT;

@end

As far for me on my project, I receive both empty and correct data, for example:

2013-03-29 20:23:40.862 ******* [5271:907] Preccessing value for : 

2013-03-29 20:23:40.863 *******[5271:907] Preccessing value for : 20/03/13
2013-03-29 20:23:40.865 *******[5271:907] Preccessing value for : 

2013-03-29 20:23:40.866 *******[5271:907] Preccessing value for : 14:07
2013-03-29 20:23:40.868 *******[5271:907] Preccessing value for :  

And this is the parsed data, and not the tags, but that's a start.

Answer 4

Go to the connection inspector of your xib of loginData view controller & remove the reference of UserEMailAddress. After that it will run. Try It... :)

Answer 5

Perhaps the issue here may be that you aren't properly conforming to Key Value Coding principals. For example, this document describes that a “key” must begin with a lowercase letter. If you don't follow the documentation to the ‘t’—especially about something as fundamental as KVC—you're likely to venture into strange, sometimes unexplainable behaviour.