Encoding and Decoding GameState Class Issue - c++

Question

I have a class named HeroState that is an inheritance from another class named CharacterProperties that contains armorId, headId, earsId and some other common values to create a character. In this new class I have declared on the header. (It is the class in charge of the players progress , by saying that It's a singleton)
#interface HeroState : CharacterProperties <NSCoding> {
ControlsType controlsType;
characterJob charJob;
MonsterJob monsterJob;
}
#property MonsterJob monsterJob;
#property characterJob charJob;
#property (readwrite)ControlsType controlsType;
+ (HeroState *) sharedInstance;
- (void)save;
#end
And I have a "database" class in charge of saving and loading the class.
database Header :
#import <Foundation/Foundation.h>
id loadData(NSString * filename);
void saveData(id theData, NSString *filename);
database Implementation :
NSString * pathForFile(NSString *filename) {
// 1
NSArray *paths =
NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask,
YES);
// 2
NSString *documentsDirectory = [paths objectAtIndex:0];
// 3
return [documentsDirectory
stringByAppendingPathComponent:filename];
}
id loadData(NSString * filename) {
// 4
NSString *filePath = pathForFile(filename);
// 5
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
// 6
NSData *data = [[[NSData alloc]
initWithContentsOfFile:filePath] autorelease];
// 7
NSKeyedUnarchiver *unarchiver = [[[NSKeyedUnarchiver alloc]
initForReadingWithData:data] autorelease];
// 8
id retval = [unarchiver decodeObjectForKey:#"Data"];
[unarchiver finishDecoding];
return retval;
}
return nil;
}
void saveData(id theData, NSString *filename) {
// 9
NSMutableData *data = [[[NSMutableData alloc] init] autorelease];
// 10
NSKeyedArchiver *archiver = [[[NSKeyedArchiver alloc]
initForWritingWithMutableData:data] autorelease];
// 11
[archiver encodeObject:theData forKey:#"Data"];
[archiver finishEncoding];
// 12
[data writeToFile:pathForFile(filename) atomically:YES];
}
But then when I use it on my HeroClass
+(HeroState*)sharedInstance {
#synchronized([HeroState class])
{
if(!sharedInstance) {
sharedInstance = [loadData(#"HeroState") retain];
if (!sharedInstance) {
[[self alloc] initWithNewStats];
}
}
return sharedInstance;
}
return nil;
}
And here for saving
- (void)save {
saveData(self, #"HeroState");
}
It gives me an error when I try to build it:
Undefined symbols for architecture i386:
"loadData(NSString*)", referenced from:
+[HeroState sharedInstance] in HeroState.o
"saveData(objc_object*, NSString*)", referenced from:
-[HeroState save] in HeroState.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I do have a initWithCoder function and a encodeWithCoder function that stick to the protocols of the NSCoding. So what could be wrong? I had this class as a NSObject inhertied class before and had no problem about it , but when I decided to recreate it being a inheritance of my CharacterProperties class that was an Inheritance of NSObject problems occurred.
I will appreciate any type of help!

Answer 1

Are you certain you wanted to declare these as C functions?
NSString * pathForFile(NSString *filename) {..}
id loadData(NSString * filename) {..}
void saveData(id theData, NSString *filename) {..}
Perhaps you should rather declare them as static class functions.
+(id) loadData:(NSString *)filename {..}
// similar for the other C functions
And call it accordingly:
sharedInstance = [[HeroState loadData:#"HeroState"] retain];
PS: please start using ARC. There's no reason not to in this day and age.