how can i store parse object directly in NsuserDefault? - ios

Question

PFQuery *Location = [PFQuery queryWithClassName:#"Location"];
[Location findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
NSLog(#"%#", [objects objectAtIndex:0]);
}];
How can i store this object in NSUserDefaults?

Answer 1

For storing custom objects u need to add these two methods in your m file of custom object class
-(void)encodeWithCoder:(NSCoder *)encoder
{
//Encode the properties of the object
[encoder encodeObject:self.contact_fname forKey:#"contact_fname"];
[encoder encodeObject:self.contact_lname forKey:#"contact_lname"];
[encoder encodeObject:self.contact_image forKey:#"contact_image"];
[encoder encodeObject:self.contact_phone_number forKey:#"contact_phone_number"];
}
-(id)initWithCoder:(NSCoder *)decoder
{
self = [super init];
if ( self != nil )
{
//decode the properties
self.contact_fname = [decoder decodeObjectForKey:#"contact_fname"];
self.contact_lname = [decoder decodeObjectForKey:#"contact_lname"];
self.contact_image = [decoder decodeObjectForKey:#"contact_image"];
self.contact_phone_number = [decoder decodeObjectForKey:#"contact_phone_number"];
}
return self;
}
then
-(void)writeArrayWithCustomObjToUserDefaults:(NSString *)keyName withArray:(NSMutableArray *)myArray
{
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:myArray];
[defaults setObject:data forKey:keyName];
[defaults synchronize];
}
-(NSArray *)readArrayWithCustomObjFromUserDefaults:(NSString*)keyName
{
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSData *data = [defaults objectForKey:keyName];
NSArray *myArray = [NSKeyedUnarchiver unarchiveObjectWithData:data];
[defaults synchronize];
return myArray;
}
use these functions for storing and reading custom object arrays
or u could simply use this library https://github.com/roomorama/RMMapper

Answer 2

There is a constraint on what kind of objects can be stored in the user defaults, detailed on the Apple documentation page:
The value parameter can be only property list objects: NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary. For NSArray and NSDictionary objects, their contents must be property list objects. See What is a Property List? in Property List Programming Guide.
You will need to convert your array of objects to an array of dictionaries, one of the ways to achieve this is to implement a toDictionary method that will take all properties and put them into a dictionary.
You'll also need the reverse method, an initWithDictionary: if you'll also want to re-create the objects from the user defaults (you can use the converted dictionaries if you want, though).
Once you have the conversion methods, you can use the NSUserDefaults methods to store and retrieve the objects.