Class $class.descriptor.multiton_config

A function that is used to create a cache key for looking up cached multiton instances. This function receives all arguments that are passed to the class's static getInstance method and is expected to return a String that uniquely identifies the combination of arguments. The arguments should be "normalized", such that if two different sets of arguments would be interpretted the same and result in equivalent instances, an identical cache key should be generated for those two different sets of arguments.

Defaults to a function that simply converts all arguments to Strings and joins them together with pipes (|).

Example:

$class("Example", {
  $multiton: {
    createCacheKey: function(name) {
      // the cache key must account for any kind of 
      // defaulting/processing of params in the constructor
      return name || "John Doe";
    }
  },
  
  // name defaults to "John Doe" if empty or null
  $constructor: function(name) {
    this._name = name || "John Doe";
  },
  
  getName() {
    return this._name;
  }
});

var example1 = Example.getInstance(null);
var example2 = Example.getInstance("John Doe");

// same name
alert(example1.getName() == example2.getName()) // alerts "true"
// same instance
alert(example1 == example2) // alerts "true"

A function that is used to create each multiton instance. This function receives all arguments that are passed to the class's static getInstance method and is expected to return an instance of the class. The function is called within the context of the class/constructor. Defaults to a function that simply instantiates the class with the same arguments that were passed to getInstance().

I'm having a hard time coming up with a legitemate use for this property, but it seemed like it should be supported to maintain consistency with $class.descriptor.singleton_config. Good luck :)