Nov 05, 2009 So yes, it's odd but they use categories to implement informal protocols. Previously, you'd use an informal protocol is some of the methods are optional; but I see now in the docs, they're trying to encourage devs to use formal protocols with optional methods rather than informal protocols.We would like to show you a description here but the site wont allow us. ios informal protocol
That is, informal protocols are now declared as @protocols with a bunch of @optional methods. In any case, an informal protocol is a collection of method declarations whereby you can optionally implement the methods to change behavior.
Informal Protocols. A fairly common pattern in ObjectiveC is the idea of an informal protocol, which is a collection of methods that a class may or may not implement. A common use is for delegate objects. In Java, it's very common for delegates to be expected to implement an interface. Im trying to use the informal protocol Creating a Missing Binding to an Informal Protocol. Is it possible to reconfigure the iOS bindingios informal protocol Formal and Informal protocols are the two varieties of protocol: An informal protocol is a category on NSObject, which implicitly makes almost all objects adopters of the protocol. (A category is a language feature that enables you to add methods to a class without subclassing it. ) Implementation of the methods in an informal protocol is optional.
Oct 07, 2013 Formal and Informal ProtocolsThere are two varieties of protocol, formal and informal: An informal protocol is a category on NSObject, which implicitly makes almost all objects adopters of the protocol. ios informal protocol The UIAccessibility informal protocol provides accessibility information about an apps user interface elements. Assistive apps, such as VoiceOver, convey this information to users with disabilities to help them use the app. Until optional protocol methods were introduced in ObjectiveC 2. 0, informal protocols were essential to the way Foundation and AppKit classes implemented delegation. A (Though with delegates that use a formal protocol, you must declare your delegate to implement that protocol; see below. ) This post is an updated version of a previous post: Quick Tip: Create your own ObjectiveC Delegate Protocol and was taken from: SO. For example, suppose you have an NSWindow.