NSKeyedUnarchiver unarchiveObjectWithData example ios

unarchiveObjectWithData:

Decodes and returns the object graph previously encoded by NSKeyedArchiver and stored in a given NSData object.

+ (id)unarchiveObjectWithData:(NSData *)data

Parameters of [NSKeyedUnarchiver unarchiveObjectWithData]

data

An object graph previously encoded by NSKeyedArchiver.

Return Value

The object graph previously encoded by NSKeyedArchiver and stored in data.

Discussion

This method raises an NSInvalidArchiveOperationException if data is not a valid archive.

Example of [NSKeyedUnarchiver unarchiveObjectWithData]

NSMutableData *data = [NSMutableData data];
for (uint32_t i = 0; i < 1024 * 1024; ++i)
    [data appendBytes:&i length:sizeof(uint32_t)];

NSData *archive = [NSKeyedArchiver archivedDataWithRootObject:[NSMutableArray arrayWithObject:data]];
NSArray *array = [NSKeyedUnarchiver unarchiveObjectWithData:archive];

assert([data isEqual:[array lastObject]]);

Example of [NSKeyedUnarchiver unarchiveObjectWithData]

- (BOOL)readFromData:(NSData *)data ofType:(NSString *)typeName error:(NSError **)outError {
    NSMutableArray *array = nil;
    NSLog(@"data is %@", data);

    @try {
        array = [NSKeyedUnarchiver unarchiveObjectWithData:data]; // line of the EXC_BAD_ACCESS
    }
    @catch (NSException * e) {
        if (outError) {
            NSDictionary *d = [NSDictionary dictionaryWithObject:@"The data is corrupted." forKey:NSLocalizedFailureReasonErrorKey];
            *outError = [NSError errorWithDomain:NSOSStatusErrorDomain code:unimpErr userInfo:d];
        }
        return NO;
    }
    [self setEmployees:array];
    return YES;
}