Serializing a custom object to a PLIST - objective-c

Question

I want to be able to take an object and write out all its properties to a PLIST. I got so far with this:
// Get the properties of the parent class
NSMutableArray *contentViewPropertyNames = [self propertyNamesOfObject:[contentView superclass]];
// Add the properties of the content view class
[contentViewPropertyNames addObjectsFromArray:[self propertyNamesOfObject:contentView]];
// Get the values of the keys for both the parent class and the class itself
NSDictionary *keyValuesOfProperties = [contentView dictionaryWithValuesForKeys:contentViewPropertyNames];
// Write the dictionary to a PLIST
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *pathAndFileName = [documentsDirectory stringByAppendingPathComponent:[dataFileName stringByAppendingString:#".plist"]];
[keyValuesOfProperties writeToFile:pathAndFileName atomically:YES];
All good, except I can't write this to a PLIST because it contains some properties that are not compliant with PLISTs, so writeToFile:atomically: fails and returns NO.
Is there a good way to serialize only those properties that are serailizable into a PLIST or modify the base class of my objects to make this work?
I realise I could archive to a binary file no problem with NSCoding however I need to be able to transfer the output between a MacOS application and an iOS app, so need to go via an intermediate, platform independent format.
Of course I could be missing the point entirely, if I have please do tell, and as always, any help is useful.
Best regards
Dave
P.S.
Here is my method to get the property names of an object:
- (NSMutableArray *)propertyNamesOfObject:(id)object {
NSMutableArray *propertyNames = nil;
unsigned int count, i;
objc_property_t *properties = class_copyPropertyList([object class], &count);
if (count > 0) {
propertyNames = [[[NSMutableArray alloc] init] autorelease];
for(i = 0; i < count; i++) {
objc_property_t property = properties[i];
const char *propName = property_getName(property);
if(propName) {
NSString *propertyName = [NSString stringWithCString:propName encoding:NSUTF8StringEncoding];
[propertyNames addObject:propertyName];
}
}
}
free(properties);
return propertyNames;
}

Answer 1

See if you can apply this function I recently wrote in a similar situation:
// Property list compatible types: NSString, NSData, NSArray, or NSDictionary */
- (BOOL)isPlistCompatibleDictionary:(NSDictionary *)dict {
NSSet *plistClasses = [NSSet setWithObjects:[NSString class], [NSData class],
[NSArray class], [NSDictionary class], [NSDate class],
[NSNumber class], nil];
BOOL compatible = YES;
NSArray *keys = [dict allKeys];
for (id key in keys) {
id obj = [dict objectForKey:key];
if (![plistClasses containsObject:[obj class]]) {
NSLog(#"not plist compatible: %#", [obj class]);
compatible = NO;
break;
}
}
return compatible;
}