Simple auto-updating connectors between two objects. Compatible with mixin.js and interface.js

associations.js

define(['underscore', 'bacon_extra', 'interface', 'mixin'],
function(_, Bacon, Interface, Mixin){
	var i_Association = new Interface({
		methods:["reflect", "get_data"]
	});
	var One = Mixin.implement({
		interface: i_Association,
		default_mixins: ["get_data", "set_data"],
		initialize: function(params){
			this.set_data = Bacon.fromClosure(function(data){
				this.data = data.toProperty(params.data);
			}.bind(this),this);
			this.set_target = Bacon.fromClosure(function(target){
				this.target = target.skipDuplicates().scan(undefined, 
					function(prev, next){
						if (prev){prev.reflect(null);}
						if (next){next.reflect(this);}
						return next;
					}
				);
			}.bind(this),this);
		},
		methods:{
			reflect: function(that){
				return this.set_target(that);
			},
			get_data: function(){
				return this.data;
			}
		}
	});
	var Many = Mixin.implement({
		interface: i_Association,
		default_mixins: ["get_data", "set_data"],
		initialize: function(params){
			this.set_data = Bacon.fromClosure(function(data){
				this.data = data.toProperty(params.data);
			}.bind(this),this);
			Bacon.fromClosure(function(ops){
				this.children = ops.scan({}, 
					function(children, op){
						return op(children) || children;
					}
				);
				this.children.onValue();
				var parent = this;
				this.target = new Bacon.Bus();
				this.target.onValue(function(params){
					var child = params.child;
					var id = (params.id || _.uniqueId("association_"));
					var parent = this;
					ops.push(function(children){
						this.data.onValue(function(data){
							if (!children[id]){
								children[id] = new One({data:data});
							};
							children[id].set_data(data);
						});
						children[id].set_target(child);
						child.reflect(children[id]);
					}.bind(this));
				}.bind(this));
				this.set_target = function(child,id){
					this.target.push({
						child:child,
						id:id
					});
					return this;
				}.bind(this);
			}.bind(this));
		},
		methods:{
			reflect: function(that){
				return this.set_target(that);
			}
		}
	});
	return {
		One: One,
		Many: Many
	}
});