What are delegates and protocols in IOS?
What exactly are protocols and delegates and how are they used in IOS?
- delegates implement protocols (another name for interfaces)
- object registers a delegate (which implements a protocol)
- The object can call protocol methods on the delegate.
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How do IOS delegates work?
A delegate allows an object to send messages to another object when an event occurs. The delegating object maintains a reference to the other object, the delegate, and at the appropriate time sends a message to it.
What is the difference between protocol and delegate in IOS?
The protocol is a set of methods (either optional or required) that would be implemented by the class that conforms to that protocol. Whereas, delegate is the reference to that class that conforms to that protocol and will adhere to the implementing methods defined in the protocol. Take a look at this Apple document for more details.
Why are delegates used in Swift?
Delegation is used for everything from handling table view events with UITableViewDelegate, to modifying cache behavior with NSCacheDelegate. The main purpose of the delegate pattern is to allow an object to communicate with its owner in a decoupled manner.
Why are delegates weak on iOS?
The reason objects weakly retain their delegates is to avoid retention cycles. Imagine the following scenario: object a creates b and holds it, then sets itself as a delegate of b. a is released by its owner, leaving a holding loop containing a and b. This is actually a very common scenario.
What is a delegate in iOS?
Delegates are extremely common in iOS development, but fortunately they’re easy to understand: a delegate is any object that should be notified when something interesting happens.
How to implement SWIFT delegate protocol for iOS?
This iOS Swift Delegate Protocol tutorial is useful for entrepreneurs looking to build an iOS app for their own startup. But we will suggest using the protocol and delegates method, as this is one of the easiest and most suggestible ways to implement.
How are delegate patterns used in iOS development?
This allows the delegate to customize the base class. Delegation is frequently used in practical iOS development. The iOS delegate pattern has a significant impact on Apple platforms. A delegation pattern allows a delegate object to send messages to another object when a specific event occurs.
What is the difference between a delegation and a protocol?
Delegates as the name suggests, delegation, that is, your representative or someone on your behalf. Protocols, on the other hand, mean a set of rules and regulations. As Apple says, a protocol defines a model of methods, properties, and other requirements that are tailored to a particular task or functionality.
How are protocols and delegates used in Cocoa?
In Cocoa frameworks, the delegate design pattern is used to specify an instance of a class that conforms to a particular protocol. This particular protocol specifies methods that the delegate class must implement to perform specific actions on given events.