how to update the array of the array of the viewModel?

[HF]

Hi all,

here is my simple data structure:

 var Feed = function (searchTerm, feeditems)
    {
        this.ID = 1;
        this.SearchTerm = searchTerm;
        this.FeedItems = ko.observable(feeditems);        
    };
 
    var FeedItem = function(userName, message)
    {
        this.UserName = userName;
        this.Message = message;
    };
 
    var viewModel = {
        Feeds: ko.observableArray(),
        ShowRenderTimes: ko.observable(false)
    };
 
    ko.applyBindings(viewModel);

I am getting initial set of Feeds (just 1 Feed for now) from server no problem:

function getLatestFeeds()
    {
        $.getJSON('/Feed/GetLatestFeeds', function (data)
        {
            $.each(data, function ()
            {
                viewModel.Feeds.push(new Feed(this.SearchTerm, this.FeedItems));
            });
        });

    }

then I am trying to update the FeedItems for that single Feed:

function getFeedData()
    {
        var url = "/Feed/GetFeedData";
        $.getJSON(url, function (data)
        {
                $.each(data, function ()
                {
                   //HERE IS THE PROBLEM: 
                    viewModel.Feeds(0).FeedItems.push(new FeedItem(data.UserName, data.Message));
                });
        });
    }

I am getting an error:

'unable to get 'push'. object is undefined..'  So what is the exact syntax to update the FeedItems of the Feed?

I understand that the question is more javascript related than knockout, but as I am getting it while trying to make ko work, I placed my question in this forum. Thanks for any help!

Al 

[shau...@gmail.com]

Hmm, definitely doable... can you help me understand exactly what you update function is supposed to do? 

It looks maybe you are trying to replace the feeditems in the first element of the feeds observable array ...? 

If you had a jsfiddle it would help a lot to help make this work.

[basil.za...@gmail.com]

The problem here is the wrong usage of an observable array: should be viewModel.Feeds()[0], not viewModel.Feeds(0), which replaces the array with 0 instead.