剔除selectedOption计算为无效

Question

I've got a weird problem that doesn't make any sense to me.

The code below will show the drop down correctly, but the selectedOptions doesn't work for reading. The read function does get called but the default of 3 isn't being set.

The write function definitely works though.

If I use fChosenAnswer instead, the default is correctly being set with #3 being preselected.

html:

 <!-- this one doesn't have a default but it should be defaulting to 3 -->
<select class="example" data-bind="options: AvailableAnswersArray, selectedOptions: ChosenAnswer"></select>

<!-- this one does correctly default to 3 -->
<select class="example2" data-bind="options: AvailableAnswersArray, selectedOptions: fChosenAnswer"></select>

in the viewmodel:

this.fChosenAnswer = ko.observableArray([3]);

this.ChosenAnswer = ko.computed({
    read: function () {
        console.log("ChosenAnswer read function is hit but the drop down doesn't show it as selected."); //this log shows in the console
        return ko.observableArray([3]);
    },
    write: function (value) {
        console.log("updated chosen answer to ", value);
        // this log shows in the console
    },
    owner: this
});

Any ideas?

Answer 1

Thanks to Adrian, the answer was to just return [3] instead of an observableArray.

read: function () {
    return [3];
},