NSCoding: Custom Class unarchived, but with empty/nil class members - ios

Question

I want to persist an NSDictionary, filled with custom Object to disc:
NSDictionary *menuList = [[NSMutableDictionary alloc]initWithDictionary:xmlParser.items];
//here the "Menu List"`s Object are filled correctly
//persisting them to disc:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);
NSString *directory = [paths objectAtIndex:0];
NSString *fileName = [NSString stringWithUTF8String:MENU_LIST_NAME];
NSString *filePath = [directory stringByAppendingPathComponent:fileName];
//saving using NSKeyedArchiver
NSData* archiveData = [NSKeyedArchiver archivedDataWithRootObject:menuList];
[archiveData writeToFile:filePath options:NSDataWritingAtomic error:nil];
//here the NSDictionary has the correct amount of Objects, but the Objects` class members are partially empty or nil
NSData *data = [NSData dataWithContentsOfFile:filePath];
NSDictionary *theMenu = (NSDictionary*)[NSKeyedUnarchiver unarchiveObjectWithData:data];
Here the .m of the Custom Object (the kind of object stored in the NSDictionary)
- (id)initWithTitle:(NSString*)tTitle level:(NSString*)tLevel state:(NSString*)tState visible:(BOOL)tVisible link:(NSString*)tLink linkType:(NSString*)tLinkType anId:(NSString*)tId {
if ((self = [super init])) {
self.anId = tId;
self.title = tTitle;
self.level = tLevel;
self.state = tState;
self.visible = tVisible;
self.link = tLink;
self.linkType = tLinkType;
}
return self;
}
- (void) encodeWithCoder:(NSCoder *)encoder {
[encoder encodeObject:self.anId forKey:#"anId"];
[encoder encodeObject:self.level forKey:#"level"];
[encoder encodeObject:self.state forKey:#"state"];
[encoder encodeBool:self.visible forKey:#"visible"];
[encoder encodeObject:self.title forKey:#"title"];
[encoder encodeObject:self.link forKey:#"link"];
[encoder encodeObject:self.linkType forKey:#"linkType"];
}
- (id)initWithCoder:(NSCoder *)decoder {
if(self == [super init]){
self.anId = [decoder decodeObjectForKey:#"anId"];
self.level = [decoder decodeObjectForKey:#"level"];
self.state = [decoder decodeObjectForKey:#"state"];
self.visible = [decoder decodeBoolForKey:#"visible"];
self.title = [decoder decodeObjectForKey:#"title"];
self.link = [decoder decodeObjectForKey:#"link"];
self.linkType = [decoder decodeObjectForKey:#"linkType"];
}
return self;
}
#end
I dont know why the objects are unarchived correctly, but the object´s members are lost somewhere. I assume there must be an error somewhere in the NSCoding methods, but I just can´t find it, any help much appreciated.

Answer 1

When you implement the initWithCoder: method, you need to call super properly:
if (self = [super initWithCoder:decoder]) {
The instance that is being unarchived has more attributes than just the additions in your specific class. You also don't want to be checking equality with self, you want to be assigning to self.