Binding

Binding consists of a few different technologies and techniques. Accessing properties based on string “keys” is called Key-Value Coding (KVC).

Observing property changes using string “keys” is called Key-Value Observing (KVO).

More information can be found on these topics at the following URLs:

Terminology

A string which is of the same name as an object’s property. Eg. age, name, value.

A dot separated list of multiple keys. For example, if we had a Person object, structured as follows:

{name:String, mom:Person, dad:Person}

A key path to a person’s mom’s name would be.

person.mom.name

For binding to work with your code, you must use one of the following patterns. <key> is the name of the property. Type is the type of your property.

function <key>():Type;

or (note uppercased key)

function is<Key>():Type;

or (note uppercased key)

function get<Key>():Type;

function set<Key>(n:Type):Void;

If no accessor functions are found for the given key, we attempt to access an internal member named <key>.

Simple tutorial that shows how to use NSArrayController with an application. However, the author is working mainly with Xcode, and very little Objective-C code is used to implement the bindings.

A structured and step-by-step tutorial, with plenty of diagrams and screenshots. Again, mainly works with Xcode.

List of Cocoa binding examples. Those of exceptional interest include the Manual Bindings, Graphic Bindings and Combatants, which establishes bindings programmatically.

Pure Objective-C tutorial on binding, however, it is in German.

Of particular interest would be the section Binding anbieten (no idea what that means) which explicitly uses + exposeBindings and - valueClassForBinding, because they’re are usually passed over due to the use of Interface Builder.