What is a delegate method?
What is a delegate method?
A delegate method is a method that the delegate object is expected to implement. Some delegate methods are required, while some are not. In IOS, most delegates are expected to conform to an Objective-C protocol; the protocol declaration will tell you which methods are optional and which are required.
What is a protocol Objective-C?
Objective-C allows you to define protocols, which declare the methods expected to be used for a particular situation. This chapter describes the syntax to define a formal protocol, and explains how to mark a class interface as conforming to a protocol, which means that the class must implement the required methods.
What is an interface in Objective-C?
In Objective-C, the class interface specifies exactly how a given type of object is intended to be used by other objects. In other words, it defines the public interface between instances of the class and the outside world.
What is an objective c delegate?
An Objective-C delegate is an object that has been assigned to the delegate property another object. To create one, you define a class that implements the delegate methods you’re interested in, and mark that class as implementing the delegate protocol.
Why we use delegates in Swift?
Delegation is used for everything from handling table view events using UITableViewDelegate , to modifying cache behavior using NSCacheDelegate . The core purpose of the delegate pattern is to allow an object to communicate back to its owner in a decoupled way.
Why delegates are type-safe?
A delegate is a type-safe function pointer that can reference a method that has the same signature as that of the delegate. You can take advantage of delegates in C# to implement events and call-back methods. A multicast delegate is one that can point to one or more methods that have identical signatures.
How is delegation accomplished in the delegate pattern?
In the delegate pattern, this is instead accomplished by explicitly passing the original object to the delegate, as an argument to a method. Note that “delegation” is often used loosely to refer to the distinct concept of forwarding, where the sending object simply uses the corresponding member on the receiving object,…
How does a delegate work in Objective-C?
Basically, delegation is a way of allowing objects to interact with each other without creating strong interdependencies between them, since this makes the design of your application less flexible.
How is delegation used in object oriented design?
Jump to navigation Jump to search. In software engineering, the delegation pattern is an object-oriented design pattern that allows object composition to achieve the same code reuse as inheritance. In delegation, an object handles a request by delegating to a second object (the delegate).
When does a delegate act on behalf of another object?
A delegate is an object that acts on behalf of, or in coordination with, another object when that object encounters an event in a program.