CODEWITHSUNDEEP
ioscocoa-touchuiviewcontrollerstoryboard
devios1
devios1

Reputation: 37985

Conventional way to implement master-detail view controllers in iOS

I just have a quick question about recommended ways to implement a master-detail view hierarchy in iOS--the kind where selecting a row in a table on one screen pushes a details view for that item onto the navigation stack.

Specifically, should I reuse the same instance of the details view controller and just change its target and reload it each time, or should I instantiate a new instance of the view controller each time?

I'd prefer the first method, as it just seems generally more efficient, but I'm having trouble figuring out how to set the target and do the reload (especially the first time, when the view controller has not yet even been initialized--I'm using storyboards and that pretty much handles all of the initialization itself).

Or perhaps instead of setting the target on the child view controller, I could set it on the parent, such that each time the child view controller is shown, it reloads itself based on the parent selection? That actually sounds like the best bet so far, just looking for tips/warnings from anyone who's run into this before.

Upvotes: 1

Views: 437

Answers (1)

rdelmar
rdelmar

Reputation: 104082

First, there's nothing wrong with creating a new view controller each time. If you use segues, that's what you'll get, since segues always instantiate new controllers. The detail controller will be deallocated when you pop or dismiss it anyway, so it won't persist.

If you want to use the same controller, you have to do your push or presentViewController in code. You can still setup the controller in the storyboard. Give it an identifier, but don't connect it up with a segue. In code, you check for the existence of your controller (you'll need a property for it), and if it doesn't exist, create it.

if (! self.detailController) {
    DetailController *dvc = [self.storyboard instantiateViewControllerWithIdentifier:@"MyIdentifier"];
}
self.dvc.whateverProperty = self.somePropertyIWantToPass; // pass some date to it
[self.navigationController pushViewController:dvc animated:YES completion:nil];

Upvotes: 2

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