CODEWITHSUNDEEP
objective-cxcodenscoding
Saranjith
Saranjith

Reputation: 11567

Pass value using NSCoding Protocol

I'm trying to pass data to detail page upon clicking a cell inside UITabelViewCell using NSCoding Protocol

NSCoder *coder =[[NSCoder alloc] init];

[coder encodeObject:@"value" forKey:@"title"];

[coder encodeObject:cell.remainderContentLabel.text forKey:@"content"];

[coder encodeObject:cell.remainderDateTimeLabel.text forKey:@"datetime"];

[coder encodeObject:cell.remainterImageView.image forKey:@"image"];

RemainderDetailViewController *detailVC = [[RemainderDetailViewController alloc] initWithCoder:coder];

[self.navigationController pushViewController:detailVC animated:YES];

But it is crashing msg is

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -encodeObject:forKey: cannot be sent to an abstract object of class NSCoder: Create a concrete instance!'

In detail page decoding is done by 

- (id) initWithCoder:(NSCoder *) aDecoder {

    if(self = [super initWithCoder:aDecoder]) {

      _remainderTitle.text =  [aDecoder decodeObjectForKey:@"title"];

      _remainderDetails.text =  [aDecoder decodeObjectForKey:@"content"];

      _dateAndTime.text =   [aDecoder decodeObjectForKey:@"datetime"];

      _remainderImage.image =  [aDecoder decodeObjectForKey:@"image"];

    }

    return self;
}

How to use 

- (void)encodeWithCoder:(NSCoder *)encoder

What is wrong im doing? Class is confirmed to NSCopying protocol

Upvotes: 0

Views: 412

Answers (2)

Ax1le
Ax1le

Reputation: 6643

AS I know - (id) initWithCoder:(NSCoder *) aDecoder is called when you load a ViewController from storyboard. If you want to push to a ViewController in the storyboard using code. You can

RemainderDetailViewController *detailVC = [[UIStoryboard storyboardWithName:@"XXX" bundle:nil] instantiateViewControllerWithIdentifier:@"yourControllerIdentifier"];
detailVC.paramDic = @{...};
[self.navigationController pushViewController:detailVC animated:YES];

The "yourControllerIdentifier" is defined in the storyboard.You can't initialize a ViewController by using the method directly. And in the destination ViewController - (id) initWithCoder:(NSCoder *) aDecoder can be fired. You can do some initial work in it.

Upvotes: 1

Willeke
Willeke

Reputation: 15587

Use a dictionary to pass a bunch of objects.

But if you want to use an archive, read the documentation of NSCoder, it says:

The NSCoder abstract class declares the interface used by concrete subclasses to transfer objects and other values between memory and some other format.

…

The concrete subclasses provided by Foundation for these purposes are NSArchiver, NSUnarchiver, NSKeyedArchiver, NSKeyedUnarchiver, and NSPortCoder.

Use NSKeyedArchiver.

Upvotes: 0

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