Delegation : By using Vetoable
Observation
- Note here every time we try to modify the variable just like observable
oldValue,newValueis printed. - But the distinction here is in the
vetoableblock, We can add a condition that determines that when the value can be set.
Code
class MainActivity : ComponentActivity()
{
private var demoObject by Delegates.vetoable(initialValue = 5) { property, oldValue, newValue ->
println("OldValue:---> $oldValue")
println("NewValue:---> $newValue")
newValue>5
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
demoObject = 2
println("Result Accessed:-> $demoObject")
println("< ----------------- >")
demoObject = 9
println("Result Accessed:-> $demoObject")
setContent {}
}
}Output
OldValue:---> 5
NewValue:---> 2
Result Accessed:-> 5
< ----------------- >
OldValue:---> 5
NewValue:---> 9
Result Accessed:-> 9