Question

I have the following code:

    function ViewModel() {
        var self = this;
        self.deckareax = ko.observable(0);
        self.deckareay = ko.observable(0);
        self.calculatedarea = ko.observable(20);
        self.deckareax.subscribe(function () {
            if (self.deckareax() == 0 || deckareay == 0) {
                self.calculatedarea(0);
            } else {
                self.calculatedarea(self.deckareax() * self.deckareay());
            }
        }
        );
        self.deckareay.subscribe(function () {
            console.log("deckareay " + self.deckareay())

            if (self.deckareax() == 0 || self.deckareay() == 0) {
                self.calculatedarea(0);
            } else {
                self.calculatedarea(self.deckareax() * self.deckareay());
            }

        }
        );
        self.deckareamxm = ko.computed({
            read: function () {
                return self.calculatedarea();
            },
            write: function (value) {
                self.calculatedarea(value);
                if ((self.deckareax() * self.deckareay(0)) != value) {
                    self.deckareax(0);
                    self.deckareay(0);
                }

            },
                owner:self
        });
    }

    ;

    ko.applyBindings(new ViewModel());

I want to be able to set the total area (deckareamxm) by either manually inputting or calcualting from entering deckareax * deckareay. If I enter a result and (deckareax * deckareay) doesn’t equal total deck area x and y should be cleared.

This pretty much works however if I enter total area it clears both but also clears itself. If I then enter again total area it stays. I think it may have got to complex. Any ideas?

Answer 1

This jsfiddle seems to do what you want. There were a couple other bugs but I primary fixed the problem by moving the self.calculatedarea(value); to the bottom of the write function.