Knockout - Checkbox - Non true/false value

http://stackoverflow.com/questions/9769955/knockout-readonly-model-binding-from-selected-item-in-dropdown

by johnpapa

HTML

<script src="https://github.com/downloads/SteveSanderson/knockout/knockout-2.0.0.debug.js"></script>
<script src="https://raw.github.com/SteveSanderson/knockout.mapping/master/knockout.mapping.js"></script>
<input type="checkbox" data-bind="checked: checkedvals.is_checked"/>
<label>Test</label><br/>

<pre data-bind="text:displayJS">
</pre>

JavaScript

var viewModel = (function() {
    var self = this;
    self.checkedvals = {
        is_checked : ko.observable(true),
        is_checked_val : ko.observable("Yes")
    };
    self.checkedvals.is_checked.subscribe(function(){
        self.checkedvals.is_checked_val(self.checkedvals.is_checked() ? "Yes" : "No");
    });

    self.displayJS = ko.computed(function() {
        return JSON.stringify(ko.toJS(checkedvals), null, 2);
    });
})();
ko.applyBindings(viewModel);