KO Dropdown

KODropdown.js

    function productSelectorViewModel(data) {
        var self = this;

        self.dataTier0 = ko.observableArray(data);
        self.dataTier1 = ko.observableArray();
        self.dataTier2 = ko.observableArray();
        self.tier0Selection = ko.observable();
        self.tier1Selection = ko.observable();
        self.tier3Selection = ko.observable();


        var tier3sub;
        function subscribeTier3() {
            tier3sub = self.tier3Selection.subscribe(function (e) {
                var event = e;
                var selection = self.tier3Selection().Label;
            });
        }
        subscribeTier3();


        self.tier0Selection.subscribe(function () {
            tier3sub.dispose();
            $.each(self.dataTier0(), function (index, item) {
                if (item.Label === self.tier0Selection().Label) {
                    self.dataTier1(item.Children);
                    if (tier3sub.isDisposed === true)
                        subscribeTier3();
                    return;
                }
            });
        });

        self.tier1Selection.subscribe(function () {
            tier3sub.dispose();
            $.each(self.dataTier1(), function (index, item) {
                if (item.Label === self.tier1Selection().Label) {
                    self.dataTier2(item.Children);
                    if (tier3sub.isDisposed === true)
                        subscribeTier3();
                    return;
                }
            });
        });
    }