Skip to main content

Execute a method when a variable value changes in Swift

This post is about how to execute a function when a variable value changes.

Instead of key-value observation, simply use a property observer for the variable. 

For e.g:

Whenever the value of variable named allSlot changes, the two lines will execute which are written in the didSet method.
private var allSlot: [String] = [] {
        didSet {
            slotTableView?.reloadData()
            enableRightBarButton()
        }
    }

Labels:

Comments

Post a Comment

Popular posts from this blog

How to kill/exit iOS application on a button click programmatically

I had been practising below code to kill an iOS application. exit(0); But last week, my application was rejected by app store due to following reason: We found that your app includes a UI control for quitting the app. This is not in compliance with the iOS Human Interface Guidelines, as required by the App Store Review Guidelines . To avoid any such rebuff, suspend the application using following code snippet. UIApplication.shared.perform(#selector(NSXPCConnection.suspend)) Good news is that now my application is passed the  iOS Human Interface Guidelines and live on app store.
Post a Comment
Read more

Return multiple values from a function in objective C

We can return tuples in swift as follows:- func getData () -> ( Int , Int , Int ) { //...code here return ( hour , minute , second ) } You can't do that in objective-c. Best option is using parameters by reference . Something like this. - ( void ) getHour :( int *) hour minute :( int *) minute second :( int *) second { * hour = 1 ; * minute = 2 ; * second = 3 ; } And use it like this. int a , b , c ; [ self getHour :& a minute :& b second :& c ]; NSLog (@ "%i, %i, %i" , a , b , c );
3 comments
Read more