An auto-mapper for inflating custom data objects from a given NSDictionary. This is a highly dangerous / unsafe category on NSObject, mainly done just as a fun exercise to see if it could be done. Can't say I recommend you use it.

NSObject+AutoMapping.m

@implementation NSObject (DataMapping)

- (instancetype)initByAutoMappingFromDictionary:(NSDictionary *)dictionary
{
  Class thisClass = [self class];
  self = [thisClass init];
  if (self)
  {
    [self mapDictionaryValues:dictionary];
  }
  return self;
}

- (void)mapDictionaryValues:(NSDictionary *)dictionary
{
  NSArray *dictKeys = [dictionary allKeys];
  for (NSString *key in dictKeys)
  {
    [self attemptToSetPropertyWithObject:dictionary[key] forKey:key];
  }
}

#pragma - mark private / helper methods

- (void)attemptToSetPropertyWithObject:(NSObject *)object forKey:(NSString *)key
{
  SEL selectorFromString = [self setterSelectorFromKeyString:key];
  if ([self respondsToSelector:selectorFromString])
  {
    [self performSelector:selectorFromString withObject:object];
  }
}

- (SEL)setterSelectorFromKeyString:(NSString *)inputString
{
  NSString *capitalizedString = [inputString capitalizedString];
  NSString *selectorString = [NSString stringWithFormat:@"set%@:", capitalizedString];
  return NSSelectorFromString(selectorString);
}

@end

Shouldn't you call self = [super init] in your initializer? In fact, you don't want to call +alloc again because your object is already allocated.

Very good point.

I see you're stripping out spaces. What is the goal of your method? Isn't the onus on the caller to provide valid inputs? There's a whole host of invalid characters (including the +[NSCharacterSet whitespaceCharacterSet]) the caller could provide. Are you sure accounting for these rules is something you want to take the burden of?

Also a great point.