How can I pass extra parameters to a custom segue? - ios

Question

I've been playing around with custom segues in iOS and am trying to use them as much as possible to allow the complete workflow of the application to be visualised in my storyboards. When I create say a popover segue, it knows about the view triggering the segue (it must in order to position the popover), but when I create a custom segue, I cannot find a way of doing the same. Is there a way of accessing the view that initiated the segue in a custom segue? Also, is there a way of passing custom parameters to a segue from Interface Builder, much like you can pass runtime arguments to a view controller?

Answer 1

You can access to the View that has triggered a custom segue by implementing the method:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
... on your View Controller.
On that method, the value of sender will be the view that triggered the segue, if you linked it using Interface Builder. When implementing this method, it is recommended to query what segue has been triggered in the following way:
if ([[segue identifier] isEqualToString:#"segueid"])
... where "segueid" would be the identifier you have given to your segue in Interface Builder.
About your second question, I don't know any way to specify parameters for a segue in Interface Builder, but you can use the same "prepareForSegue" method, to pass them from your View Controller at Runtime.
Imagine that your custom segue has a property called animationStyle
if the perform method, you can have the following:
- (void)perform
{
switch (self.animationStyle) {
case 0:
// TODO Perform animation type 0
case 1:
// TODO Perform animation type 1
}
}
Then, let's say you have a couple of View Controllers where you want to use that custom segue. In the first one you can implement the performSegue method like:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"yourCustomSegueID"]) {
((YourCustomSegueClass *)segue).animationStyle = 0;
}
}
While in the second view controller you can implement it like:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"yourCustomSegueID"]) {
((YourCustomSegueClass *)segue).animationStyle = 1;
}
}
... So effectively, you are reusing the same custom segue class for getting different effects. It is still true that IB will not let you configure the segue directly, but there's no way around that as far as I know.