knockout.js dynamic field binding with variable

Question

Is there a way to dynamically replace the field being written to and read from in the ko.computed? For example, with this function, I want to replace the self.JobStartDate with a variable fieldname that I could pass in:

function Job(data) {
    var self = this;
    ko.mapping.fromJS(data, {}, this); 

    var computedDateFn = {
        read: function() {
            return formatDate(ko.utils.unwrapObservable(self.JobStartDate), true);
        },

        write: function(value) {
            var jsonDate = "/Date(" + Date.parse(value).getTime();
            self.JobStartDate(jsonDate);
        }
    }

    this.formattedStartDate = ko.computed(computedDateFn);
    this.formattedEndDate = ko.computed(computedDateFn); // this guy would need the field it writes to/reads from to be self.JobEndDate
}

Answer 1

If you make computedDateFn a function that accepts your fieldname as string and returns the object defining your computed observable, you can use array notation like this...

http://jsfiddle.net/bczengel/tMTCV/