loading a knockout.js observableArray() from .ajax() call

Question

This puzzles me. It must be something small I'm not seeing. I'm trying to load a very simple observableArray in knockout with an ajax call.

javascript

// we bind the array to the view model property with an empty array.
var data = [];   
var viewModel = {
    vendors: ko.observableArray(data)
};
ko.applyBindings(viewModel);

$(function () {
    // on this click event, we popular the observable array
    $('#load').click(function () {
        // WORKS. Html is updated appropriately.
        viewModel.vendors([{ "Id": "01" },{ "Id": "02" },{ "Id": "03" }]);

        // DOES NOT WORK. Fiddler2 shows the same exact json string come back 
        // as in the example above, and the success function is being called.
        $.ajax({
            url: '/vendors/10',
            dataType: 'json',
            success: function (data) {
                viewModel.vendors(data);
            }
        });
    });
});

html

<button id="load">Load</button>
<ul data-bind="template: { foreach: vendors }">
    <li><span data-bind="text: Id"></span></li>
</ul>

---

Question: Why does the successful ajax call, who's data variable value matches byte-for-byte the hard typed value, not trigger the html refresh?

Answer 1

There is no reason this would not work fine. As this demonstrates.

http://jsfiddle.net/madcapnmckay/EYueU/

I would check that the ajax post is actually returning json data and that that json is an array and that it's being parsed correctly.

I had to tweak the ajax call to get the fiddle ajax handlers to work correctly.

Nothing more I can think of.

Hope this helps.