Clever Geek Handbook

Save custom objects to NSUserDefaults

I am trying to save custom objects as follows, but I am getting an error.

// store data
NSMutableArray *archiveArray = [NSMutableArray arrayWithCapacity:pOrderElements.count];
for (id orderObject in pOrderElements) {
    NSData *personEncodedObject = [NSKeyedArchiver archivedDataWithRootObject:orderObject];
    [archiveArray addObject:personEncodedObject];
}

NSUserDefaults *userData = [NSUserDefaults standardUserDefaults];
[userData setObject:archiveArray forKey:@"personDataArray"];


// retrive data
NSData *data = [userData objectForKey:@"personDataArray"];
// the following line throws an error
id retrieveData = [NSKeyedUnarchiver unarchiveObjectWithData:data];

here is my pOrderElements

(lldb) po pOrderElements
<__NSArrayM 0x174256b90>(
{
    category = 1;
    imagePath = "products/chicken-kabob.png";
    name = "Baked Chicken";
    price = "5.49";
}
)

Application terminated due to uncaught 'NSInvalidArgumentException', reason: '- [__ NSCFArray bytes]: unrecognized selector sent to instance 0x174264f40'

+1


source to share


2 answers


You are deleting an invalid object. You store NSArray in NSUserDefaults



NSArray * archiveArray = [userData objectForKey:@"personDataArray"];
for (NSData *personEncodedObject in archiveArray) {
    id personObject = [NSKeyedUnarchiver unarchiveObjectWithData:personEncodedObject];
}
+2


source


First, you create a custom class. As shown below.

CustomObject.h

#import <Foundation/Foundation.h>

@interface CustomObject : NSObject

@property(strong,nonatomic)NSString *name;

@end

CustomObject.m

#import "CustomObject.h"

@implementation CustomObject



- (void)encodeWithCoder:(NSCoder *)encoder {
    //Encode properties, other class variables, etc
    [encoder encodeObject:self.name forKey:@"name"];

}

- (id)initWithCoder:(NSCoder *)decoder {
    if((self = [super init])) {
        //decode properties, other class vars
        self.name = [decoder decodeObjectForKey:@"name"];

    }
    return self;
}


Then create an object of the class CustomObject

and store it inNSUserDefaults

Saved your object this way

CustomObject *object =[CustomObject new];
object.name = @"test";

NSMutableArray *arr = [[NSMutableArray alloc]init];
[arr  addObject:object];

NSData *encodedObject = [NSKeyedArchiver archivedDataWithRootObject:arr];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:encodedObject forKey:@"storeObject"];
[defaults synchronize];

get custom object from NSUserDefaults

like this

NSData *storedEncodedObject = [defaults objectForKey:@"storeObject"];
    NSArray *arrStoreObject = [NSKeyedUnarchiver unarchiveObjectWithData:storedEncodedObject];
    for (int i=0; i<arrStoreObject.count; i++)
    {
        CustomObject *storedObject = [arrStoreObject objectAtIndex:i];
        NSLog(@"%@",storedObject.name);

    }
+1


source






More articles:


All Articles