A Boolean value indicating whether the operation can be performed now.
- iOS 2.0+
- macOS 10.5+
- UIKit for Mac 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
The readiness of operations is determined by their dependencies on other operations and potentially by custom conditions that you define. The
NSOperation class manages dependencies on other operations and reports the readiness of the receiver based on those dependencies.
If you want to use custom conditions to define the readiness of your operation object, reimplement this property and return a value that accurately reflects the readiness of the receiver. If you do so, your custom implementation must get the default property value from
super and incorporate that readiness value into the new value of the property. In your custom implementation, you must generate KVO notifications for the
is key path whenever the ready state of your operation object changes. For more information about generating KVO notifications, see Key-Value Observing Programming Guide.