Does Segue Exist?

Question

Does anyone know if there is a way to determine whether a segue with a particular name exists? Or alternatively, if there's a way to get a list of all the named segues that iOS knows about

Answer 1

no, your method only detect when a particular segue is fired. but you can't test if a segue exist, by another way than try to call it. it seems that the only way is to use @try @catch :

@try {
    [self performSegueWithIdentifier:@"Replace_Connected" sender:self];
}
@catch (NSException *exception) {
    NSLog(@"%@  no segue with identifier 'Replace_Connected' : %@", [self description], exception);
}
@finally {    }

Answer 2

I suggest you file a bug. The storyboard clearly knows all the segues emanating from a given scene:

<viewController id="2" customClass="ViewController" sceneMemberID="viewController">
    <view key="view" contentMode="scaleToFill" id="3">
        <rect key="frame" x="0.0" y="20" width="320" height="460"/>
        <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
    </view>
    <connections>
        <segue destination="t3N-Fe-gqq" kind="modal" identifier="myCoolSegue" id="AYQ-C4-4vO"/>
    </connections>
</viewController>

So why isn't a view controller instance allowed to ask for that information? Also, a view controller has a storyboard property so why doesn't it have a segues property? I think you have legitimate grounds for a feature request.

Answer 3

You can check to see if a Segue exists by using the prepareForSegue method :

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    // Make sure we are dealing with the proper Segue
    if ([segue.identifier isEqualToString:@"MySegueID"]) {
        // Exists, do something
    }
}

If there is a way to list all the Segues, I don't know about it and I haven't seen it in the docs.