Custom Group in Windows Store App

In this article I describe how to create Windows Store Apps for Custom Data Group using JavaScript.

Introduction

In this article I describe how to create Windows Store App for Custom Data Group using JavaScript. The item data adapter needs to supply the items sorted by group. It also must provide a group Key for each item to specify the group.

I assume you can create a simple Windows Store App using JavaScript; for more help visit Simple Windows Store Apps using JavaScript.

To start the creation of the app, add one JavaScript page by right-clicking on the js folder in the Solution Explorer and select "Add" > "New item" > "JavaScript Page" and then provide an appropriate name. In the same way, add a HTML page to your project.

custom-group-in-windows-store-app-.jpg

Write the following code in the default.html

<!DOCTYPE html>

<html>

<head>

    <meta charset="utf-8" />

    <title></title>

    <link rel="stylesheet" href="//Microsoft.WinJS.1.0/css/ui-light.css" />

    <script src="//Microsoft.WinJS.1.0/js/base.js"></script>

    <script src="//Microsoft.WinJS.1.0/js/ui.js"></script>

    <link rel="stylesheet" href="/css/default.css" />

    <script src="/js/default.js"></script>

</head>

<body role="application"style="background-color:lightpink">

    <center><div id="rootGrid">

        <div id="content">

            <h1 id="featureLabel"></h1>

            <div id="contentHost"></div>

        </div>

    </div></center>

</body>

</html>

Write the following code in the default.js

(function () {

    "use strict";

    var appTitle = "";

    var pages = [

        { url: "page.html"}

    ];

    function activated(eventObject) {

        if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) {

            eventObject.setPromise(WinJS.UI.processAll().then(function () {

                var url = WinJS.Application.sessionState.lastUrl || pages[0].url;

                return WinJS.Navigation.navigate(url);

            }));

        }

    }

    WinJS.Navigation.addEventListener("navigated", function (eventObject) {

        var url = eventObject.detail.location;

        var host = document.getElementById("contentHost");

        host.winControl && host.winControl.unload && host.winControl.unload();

        WinJS.Utilities.empty(host);

        eventObject.detail.setPromise(WinJS.UI.Pages.render(url, host, eventObject.detail.state).done(function () {

            WinJS.Application.sessionState.lastUrl = url;

        }));

    });

    WinJS.Namespace.define("App", {

        appTitle: appTitle,

        pages: pages

    });

    WinJS.Application.addEventListener("activated", activated, false);

    WinJS.Application.start();

})(); 


Write the following code in the page.html

<!DOCTYPE html>

<html>

<head>

    <title></title>

    <script src="/js/script.js"></script>

</head>

<body>

    <div data-win-control="App.pageInput">

    </div>

    <div data-win-control="App.pageOutput">

        <div id="mediumListIconTextTemplate" data-win-control="WinJS.Binding.Template">

            <div class="mediumListIconTextItem">

                <img class="mediumListIconTextItem-Image" data-win-bind="src: picture" />

                <div class="mediumListIconTextItem-Detail">

                    <h4 data-win-bind="innerText: title"></h4>

                </div>

            </div>

        </div>

        <div id="groupTemplate" data-win-control="WinJS.Binding.Template">

            <div class="groupHeader">

                <h2 data-win-bind="innerText: type"></h2>

            </div>

        </div>

        <div id="listView4" class="win-selectionstylefilled">

        </div>

    </div>

</body>

</html>

Write the following code in the script.js
 

(function () {

    "use strict";

    var page = WinJS.UI.Pages.define("page.html", {

        ready: function (element, options) {

            initData();

            var listView4 = new WinJS.UI.ListView(document.getElementById("listView4"), {

                itemDataSource: itemDataSource,

                groupDataSource: groupDataSource,

                itemTemplate: document.getElementById("mediumListIconTextTemplate"),

                groupHeaderTemplate: document.getElementById("groupTemplate"),

                layout: new WinJS.UI.GridLayout()

            });

        }

    });

    var flavors = [

        { title: "1", kind: "1", picture: "images/1.jpg", stock: "in_stock" },

        { title: "2", kind: "1", picture: "images/2.jpg", stock: "in_stock" },

        { title: "1", kind: "2", picture: "images/1.jpg", stock: "in_stock" },

        { title: "2", kind: "2", picture: "images/2.jpg", stock: "in_stock" }

    ];

    var desertTypes = [

        { key: "1", type: "group1" },

        { key: "2", type: "group2" }

    ];

    var itemDataSource, groupDataSource;

    function initData() {

        var groupKeys = [];

        for (var i = 0; i < desertTypes.length; i++) {

            groupKeys[i] = desertTypes[i].key;

        }

        var itemData = flavors;

        itemData.sort(function CompareForSort(item1, item2) {

            var first = groupKeys.indexOf(item1.kind), second = groupKeys.indexOf(item2.kind);

            if (first === second) { return 0; }

            else if (first < second) { return -1; }

            else { return 1; }

        });

        var itemIndex = 0;

        for (var j = 0, len = desertTypes.length; j < len; j++) {

            desertTypes[j].firstItemIndex = itemIndex;

            var key = desertTypes[j].key;

            for (var k = itemIndex, len2 = itemData.length; k < len2; k++) {

                if (itemData[k].kind !== key) {

                    itemIndex = k;

                    break;

                }

            }

        }

        itemDataSource = new flavorsDataSource(itemData);

        groupDataSource = new desertsDataSource(desertTypes);

    }

    var flavorsDataAdapter = WinJS.Class.define(

        function (data) {

            this._itemData = data;

        },

        {

            getCount: function () {

                var that = this;

                return WinJS.Promise.wrap(that._itemData.length);

            },

            itemsFromIndex: function (requestIndex, countBefore, countAfter) {

                var that = this;

 

                if (requestIndex >= that._itemData.length) {

                    return WinJS.Promise.wrapError(new WinJS.ErrorFromName(WinJS.UI.FetchError.doesNotExist));

                }

 

                var lastFetchIndex = Math.min(requestIndex + countAfter, that._itemData.length - 1);

                var fetchIndex = Math.max(requestIndex - countBefore, 0);

                var results = [];

                for (var i = fetchIndex; i <= lastFetchIndex; i++) {

                    var item = that._itemData[i];

                    results.push({

                        key: i.toString(),

                        groupKey: item.kind,

                        data: item

                    });

                }

                return WinJS.Promise.wrap({

                    items: results,

                    offset: requestIndex - fetchIndex,

                    totalCount: that._itemData.length

                });

            }

        });

    var flavorsDataSource = WinJS.Class.derive(WinJS.UI.VirtualizedDataSource, function (data) {

        this._baseDataSourceConstructor(new flavorsDataAdapter(data));

    });

    var desertsDataAdapter = WinJS.Class.define(

        function (groupData) {

            this._groupData = groupData;

        },

        {

            getCount: function () {

                var that = this;

                return WinJS.Promise.wrap(that._groupData.length);

            },

            itemsFromIndex: function (requestIndex, countBefore, countAfter) {

                var that = this;

 

                if (requestIndex >= that._groupData.length) {

                    return Promise.wrapError(new WinJS.ErrorFromName(UI.FetchError.doesNotExist));

                }

                var lastFetchIndex = Math.min(requestIndex + countAfter, that._groupData.length - 1);

                var fetchIndex = Math.max(requestIndex - countBefore, 0);

                var results = [];

                for (var i = fetchIndex; i <= lastFetchIndex; i++) {

                    var group = that._groupData[i];

                    results.push({

                        key: group.key,

                        firstItemIndexHint: group.firstItemIndex,

                        data: group

                    });

                }

                return WinJS.Promise.wrap({

                    items: results,

                    offset: requestIndex - fetchIndex,

                    totalCount: that._groupData.length

                });

            },

            itemsFromKey: function (requestKey, countBefore, countAfter) {

                var that = this;

                var requestIndex = null;

                for (var i = 0, len = that._groupData.length; i < len; i++) {

                    if (that._groupData[i].key === requestKey) {

                        requestIndex = i;

                        break;

                    }

                }

                if (requestIndex === null) {

                    return WinJS.Promise.wrapError(new WinJS.ErrorFromName(WinJS.UI.FetchError.doesNotExist));

                } 

                var lastFetchIndex = Math.min(requestIndex + countAfter, that._groupData.length - 1);

                var fetchIndex = Math.max(requestIndex - countBefore, 0);

                var results = [];

                for (var j = fetchIndex; j <= lastFetchIndex; j++) {

                    var group = that._groupData[j];

                    results.push({

                        key: group.key,

                        firstItemIndexHint: group.firstItemIndex,

                        data: group

                    });

                }

                return WinJS.Promise.wrap({

                    items: results,

                    offset: requestIndex - fetchIndex,

                    absoluteIndex: requestIndex,

                    totalCount: that._groupData.length

                });

            }, 

        });

    var desertsDataSource = WinJS.Class.derive(WinJS.UI.VirtualizedDataSource, function (data) {

        this._baseDataSourceConstructor(new desertsDataAdapter(data));

    }); 

})();
 

Output

custom-group-in-windows-store-app.jpg

Summary

In this article I described how to create a Windows Store App for Custom Data Group using JavaScript. I hope this article has helped you to understand this topic. Please share it. If you know more about this, your feedback and constructive contributions are welcome.