Knockout.js 计算出的 observable 没有绑定到 observable 数组

Question

I'm trying to get computed value and push these values to the observable array. Web Api controller returning simple values - just pure numbers without json wrap. May be this is issue. Please advise as I'm newbie to Knockout. PS Here is two ajax call because they are calling different api's controllers.

 function GrafikViewModel(grafikUri) {
            var self = this;
            self.books = ko.observableArray();
            self.PaxLeft = ko.computed(function () {
                ko.utils.arrayForEach(self.books(), function (book) {
                    $.getJSON("/api/orders/getpax/" + book.kodg, function (item) {
                        self.books().push(item);
                    });
                }, GrafikViewModel)
            });
            $.getJSON(grafikUri, function (data) {
                self.books(data.$values);
            });
        }

Answer 1

I have to do a little guess work, but I believe what you want is

self.books.push(item);

instead of

self.books().push(item);

Note the missing () there. The knockout observable array "mirrors" most of the array's functions. By using those instead of the ones provided by Array , knockout can keep track of changes happening to the wrapped array.

EDIT: You can find a list of all the "mirrored" functions at http://knockoutjs.com/documentation/observableArrays.html#manipulating-an-observablearray , about two pages down (section "Manipulating an observableArray")