knockout custom numeric binding

    The details for entering only the number is given in this link : http://jsfiddle.net/mbest/n4z8Q/

    Try this below code :

<span data-bind="text: Interval" ></span>
<input data-bind="numeric, value: Interval" />

    Use the extender method for this to enter only the numeric .

    Strip out the non-numeric characters If the input is not a number . So non-numeric input is entered .

    Intercept the value by subscribe to the observable before it updates . Therefore do not follow the keypress. Next, Do some regex which permit to check whether the input is a number or not.

FIDDLE:

In the HTML :

<input type="text" data-bind="value: myNum, valueUpdate: 'afterkeyup'" />

In the JS :

(function(ko) {
    ko.observable.fn.numeric = function () {
        // the observable we are extending
        var target = this;
        // subscribe to the observable so we can
        // intercept the value and do our custom
        // processing.
        this.subscribe(function() {
            var value = target();
            // this will strip out any non numeric characters
            target(value.replace(/[^0-9]+/g,'')); //[^0-9\.]/g - allows decimals
        }, this);
        return target;
    };
    function ViewModel() {
        this.myNum = ko.observable().numeric();
    };
    ko.applyBindings(new ViewModel());
})(ko);

    Try this method for custom numeric binding .

    Check this link for required information  http://numeraljs.com/. The user should  hook up the settings and on update the user should call format on the input.