Question

I have just started using Knockout and I want to filter my data that I am displaying in my UI by selecting an item from a dropdown. I have got so far, but I cannot get the selected value from my dropdown yet, and then after that I need to actually filter the data displayed based upon that value. Here is my code so far :

    @model Models.Fixture

@{
    ViewBag.Title = "Fixtures";
    Layout = "~/Areas/Development/Views/Shared/_Layout.cshtml";
}
@Scripts.Render("~/bundles/jqueryval")
<script type="text/javascript" src="@Url.Content("~/Scripts/knockout-2.1.0.js")"></script>
<script type="text/javascript">

    function FixturesViewModel() {
            var self = this;
            var baseUri = '@ViewBag.ApiUrl';
            self.fixtures = ko.observableArray();
            self.teams = ko.observableArray();

            self.update = function (fixture) {

                $.ajax({ type: "PUT", url: baseUri + '/' + fixture.Id, data: fixture });
            };

            self.sortByAwayTeamScore = function () {
                this.fixtures.sort(function(a, b) 
                { return a.AwayTeamScore < b.AwayTeamScore ? -1 : 1; });
            };

            self.select = function (team) {

            };

            $.getJSON("/api/fixture", self.fixtures);
            $.getJSON("/api/team", self.teams);
    }

    $(document).ready(function () {
        ko.applyBindings(new FixturesViewModel());
    }); 

  </script>

<div class="content">
    <div>
        <table><tr><td><select data-bind="options: teams, optionsText: 'TeamName', optionsCaption: 'Select...', optionsValue: 'TeamId', click: $root.select"> </select></td></tr></table>
        <table class="details ui-widget-content">
            <thead>
                <tr><td>FixtureId</td><td>Season</td><td>Week</td><td>AwayTeam</td><td><a id="header" data-bind='click: sortByAwayTeamScore'>AwayTeamScore</a></td><td>HomeTeam</td><td>HomeTeamScore</td></tr>
            </thead>    
            <tbody data-bind="foreach: fixtures">
                <tr>
                    <td><span data-bind="text: $data.Id"></span></td>
                    <td><span data-bind="text: $data.Season"></span></td>
                    <td><span data-bind="text: $data.Week"></span></td>
                    <td><span data-bind="text: $data.AwayTeamName"></span></td>
                    <td><input type="text" data-bind="value: $data.AwayTeamScore"/></td>
                    <td><span data-bind="text: $data.HomeTeamName"></span></td>
                    <td><input type="text" data-bind="value: $data.HomeTeamScore"/></td>
                    <td><input type="button" value="Update" data-bind="click: $root.update"/></td>
                </tr>
            </tbody>
        </table>
    </div>
</div>

EDIT : Figured this out :

    <script type="text/javascript">

function FixturesViewModel() {
        var self = this;
        var baseUri = '@ViewBag.ApiUrl';
        self.fixtures = ko.observableArray();

        self.teams = ko.observableArray();
        self.TeamName = ko.observable('');

        self.filteredItems = ko.computed(function () {

            var TeamName = self.TeamName();
                if (!TeamName || TeamName == "None") {

                            return self.fixtures();
                        } else {
                            return ko.utils.arrayFilter(self.fixtures(), function (i) {
                                return i.AwayTeamName == TeamName;
                            });
                }
        });

        self.update = function (fixture) {
            $.ajax({ type: "PUT", url: baseUri + '/' + fixture.Id, data: fixture });
        };

        self.sortByAwayTeamScore = function () {
            this.fixtures.sort(function(a, b) 
            { return a.AwayTeamScore < b.AwayTeamScore ? -1 : 1; });
        };

        $.getJSON("/api/fixture", self.fixtures);
        $.getJSON("/api/team", self.teams);
}

$(document).ready(function () {
    ko.applyBindings(new FixturesViewModel());
}); 

<select data-bind="options: teams, optionsText: 'TeamName', optionsCaption: 'Select...', optionsValue: 'TeamName', value:TeamName"> </select>

Answer 1

Filtering in knockout is generally done with a computed observable. Here is a basic ViewModel that could filter based on a dropdown of types (including a filter option for “none”).

var ViewModel = function(data) {
    var self = this;
    self.filters = ko.observableArray(data.filters);
    self.filter = ko.observable('');
    self.items = ko.observableArray(data.items);
    self.filteredItems = ko.computed(function() {
        var filter = self.filter();
        if (!filter || filter == "None") {
            return self.items();
        } else {
            return ko.utils.arrayFilter(self.items(), function(i) {
                return i.type == filter;
            });
        }
    });
};

Here is that code in a fiddle, so you can play with it.