2.03 - emulating interfaces with duck typing.js

来自「JS设计模式源代码」· JavaScript 代码 · 共 19 行

// Interfaces.

var Composite = new Interface('Composite', ['add', 'remove', 'getChild']);
var FormItem = new Interface('FormItem', ['save']);

// CompositeForm class

var CompositeForm = function(id, method, action) {
   ...
};

...

function addForm(formInstance) {
    ensureImplements(formInstance, Composite, FormItem);
    // This function will throw an error if a required method is not implemented.
    ...
}