Bind to float / numbers. ("") is added to json model #2

https://groups.google.com/forum/#!topic/knockoutjs/5WcUS2Od9NM

by rniemeyer

HTML

<script src="http://knockoutjs.com/js/jquery.tmpl.js"></script>
<script src="http://knockoutjs.com/downloads/knockout-2.2.1.js"></script>
<label>Bad: </label>
<input data-bind="value: units" size="3" />
<span data-bind="text: ko.toJSON(units)"></span>
<hr/>
<label>Good: </label>
<input data-bind="value: units2" size="3" />
<span data-bind="text: ko.toJSON(units2)"></span>
<hr/>

JavaScript

ko.numericObservable = function(initialValue) {
    var _actual = ko.observable(initialValue);
    
    var result = ko.dependentObservable({
        read: function() {
          return _actual();  
        },
        write: function(newValue) {
           var parsedValue = parseFloat(newValue);
            _actual(isNaN(parsedValue ) ? newValue: parsedValue);
        } 
    });
    
    return result;
};

var viewModel = {
    units: ko.observable(2.50),
    units2: ko.numericObservable(2.50)
};


ko.applyBindings(viewModel);