Getting Started with the Badge

This tutorial explains how to set up a basic Telerik UI for ASP.NET Core Badge and highlights the major steps in the configuration of the component.

Usually, the Badges are used as labels over buttons and links to provide information about notifications, updates, messages, and more. You will initialize differently styled Badges integrated into the items of a navigation AppBar component. Next, you will learn how to reference the client-side instance of the component and control its behavior by using the available API methods. Finally, you can run the sample code in Telerik REPL and continue exploring the components.

Prerequisites

To successfully complete the tutorial, you need a project that is already configured to use the Telerik UI for ASP.NET Core components:

You can use the Telerik REPL playground and skip installing the components on your system and configuring a project.
You can prepare a Visual Studio project by following the following guide:
- Creating a new pre-configured project for the Telerik UI for ASP.NET Core components from a project template.

1. Prepare the CSHTML File

The first step is to add the required directives at the top of the .cshtml document:

To use the Telerik UI for ASP.NET Core HtmlHelpers:
```
@using Kendo.Mvc.UI
```
To use the Telerik UI for ASP.NET Core TagHelpers:
```
@addTagHelper *, Kendo.Mvc
```

Optionally, you can structure the View content by adding the desired HTML elements like headings, divs, paragraphs, and others.

    @using Kendo.Mvc.UI

    <h4>Navigation AppBar with Badges</h4>
    <div>

    </div>

    @addTagHelper *, Kendo.Mvc

    <h4>Navigation AppBar with Badges</h4>
    <div>

    </div>

2. Initialize the Badge

Use the Badge HtmlHelper or TagHelper to add the component to a page:

The Name() configuration method is mandatory as its value is used for the id and the name attributes of the Badge element.
The Text() option specifies the content that will be displayed in the Badge. Alternatively, you can display an icon instead of a text by setting the name for an existing icon in the Kendo UI theme or SVG content through the Icon() option.
The Position method lets you define the position of the Badge relative to the edge of the container.
The Align method allows you to set the position of the Badge relative to its container.

    @using Kendo.Mvc.UI

    <span class='k-icon k-i-cart'>
        @(Html.Kendo().Badge()
            .Name("shoppingCartBadge")
            .Text("+10")
            .Position(BadgePosition.Outside)
            .Align(BadgeAlign.TopStart)
        )
    </span>

    @addTagHelper *, Kendo.Mvc

    <span class='k-icon k-i-cart'>
        <kendo-badge name="shoppingCartBadge" 
            text="+10" 
            position="BadgePosition.Outside"
            align="BadgeAlign.TopStart">
        </kendo-badge>
    </span>

3. Integrate Badges into UI Components

The next step is to create an AppBar component and integrate Badges in its items.

Use the Template component to define an icon and a Badge into the AppBar's items.

    @using Kendo.Mvc.UI

    @(Html.Kendo().AppBar()
        .Name("appbar")
        .ThemeColor(AppBarThemeColor.Dark)
        .HtmlAttributes(new { style = "height: 50px;"})
        .Items(items =>
        {
            items.Add().Template(Html.Kendo().Template()
                .AddHtml("<span class='k-icon k-i-envelop'>")
                .AddComponent(badge => badge
                    .Badge()
                        .Name("messagesBadge")
                        .Text("+2")
                        .Position(BadgePosition.Edge)
                        .Align(BadgeAlign.TopEnd)
                )
                .AddHtml("</span>")
            )
            .Type(AppBarItemType.ContentItem);
            items.Add().Type(AppBarItemType.Spacer).Width("16px");
            items.Add().Template(Html.Kendo().Template()
                .AddHtml("<span class='k-icon k-i-notification'>")
                .AddComponent(badge => badge
                    .Badge()
                        .Name("notificationsBadge")
                        .Text("+5")
                        .Position(BadgePosition.Edge)
                        .Align(BadgeAlign.TopEnd)
                )
                .AddHtml("</span>")
            )
            .Type(AppBarItemType.ContentItem);
            items.Add().Type(AppBarItemType.Spacer).Width("10px");
            items.Add().Template(Html.Kendo().Template()
                .AddComponent(ddb => ddb
                    .DropDownButton()
                        .Name("profileDDB")
                        .FillMode(FillMode.Flat)
                        .Icon("user")
                        .Items(items=>{
                            items.Add().Id("user-profile").Text("Profile").Icon("folder").Click(@<text>function() { alert("Enter Profile") }</text>);
                            items.Add().Id("user-settings").Text("Settings").Icon("gear").Click(@<text>function() { alert("Profile Settings") }</text>);
                            items.Add().Id("user-logout").Text("Log out").Icon("x").Click(@<text>function() { alert("Log out") }</text>);
                        })
                )
            )
            .Type(AppBarItemType.ContentItem);
            items.Add().Type(AppBarItemType.Spacer).Width("10px");
            items.Add().Template(Html.Kendo().Template()
                .AddHtml("<span class='k-icon k-i-cart'>")
                .AddComponent(badge => badge
                    .Badge()
                        .Name("shoppingCartBadge")
                        .Text("+10")
                        .Position(BadgePosition.Outside)
                        .Align(BadgeAlign.TopStart)
                )
                .AddHtml("</span>")
            )
            .Type(AppBarItemType.ContentItem);
            items.Add().Type(AppBarItemType.Spacer);
        })
    )

    @addTagHelper *, Kendo.Mvc

    <kendo-appbar name="appbar" theme-color="AppBarThemeColor.Dark" style="height: 50px;">
        <items>
            <appbar-item type="AppBarItemType.ContentItem">
                <template>
                <span class='k-icon k-i-envelop'>
                    <kendo-badge name="messagesBadge" 
                        text="+2" 
                        position="BadgePosition.Edge"
                        align="BadgeAlign.TopEnd">
                    </kendo-badge>
                </span>
                </template>
            </appbar-item>
            <appbar-item width="16px" type="AppBarItemType.Spacer"></appbar-item>
            <appbar-item type="AppBarItemType.ContentItem">
                <template>
                    <span class='k-icon k-i-notification'>
                        <kendo-badge name="notificationsBadge" 
                            text="+5" 
                            position="BadgePosition.Edge"
                            align="BadgeAlign.TopEnd">
                        </kendo-badge>
                    </span>
                </template>
            </appbar-item>
            <appbar-item width="10px" type="AppBarItemType.Spacer"></appbar-item>
            <appbar-item type="AppBarItemType.ContentItem">
                <template>
                    <kendo-dropdownbutton name="profileDDB" icon="user" fill-mode="FillMode.Flat">
                        <dropdownbutton-items>
                            <item id="user-profile" text="Profile" icon="folder"></item>
                            <item id="user-settings" text="Settings" icon="gear"></item>
                            <item id="user-logout" text="Log out" icon="x"></item>
                        </dropdownbutton-items>
                    </kendo-dropdownbutton>
                </template>
            </appbar-item>
            <appbar-item width="10px" type="AppBarItemType.Spacer"></appbar-item>
            <appbar-item type="AppBarItemType.ContentItem">
                <template>
                    <span class='k-icon k-i-cart'>
                        <kendo-badge name="shoppingCartBadge" 
                            text="+10" 
                            position="BadgePosition.Outside"
                            align="BadgeAlign.TopStart">
                        </kendo-badge>
                    </span>
                </template>
            </appbar-item>
            <appbar-item type="AppBarItemType.Spacer"></appbar-item>
        </items>
    </kendo-appbar>

The Button component provides built-in Badges, so you can use the Badge() configuration of the Button HtmlHelper or the badge tag of the Button TagHelper to decorate a button in the AppBar.

    @using Kendo.Mvc.UI

    @(Html.Kendo().AppBar()
        .Name("appbar")
        .ThemeColor(AppBarThemeColor.Dark)
        .HtmlAttributes(new { style = "height: 50px;"})
        .Items(items =>
        {
            items.Add().Template(Html.Kendo().Template()
                .AddComponent(ddb => ddb
                    .Button()
                    .Name("newsBtn")
                    .Content("Home")
                    .Badge(b => b
                        .Position(BadgePosition.Inline)
                        .Icon("home")
                    )
                )
            )
            .Type(AppBarItemType.ContentItem);
        })
    )

    @addTagHelper *, Kendo.Mvc

    <kendo-appbar name="appbar" theme-color="AppBarThemeColor.Dark" style="height: 50px;">
        <items>
            <appbar-item type="AppBarItemType.ContentItem">
                <template>
                    <kendo-button name="newsBtn">
                        <badge
                            icon="home"
                            position="BadgePosition.Inline"/>
                        Home
                    </kendo-button>
                </template>
            </appbar-item>
        </items>
    </kendo-appbar>

4. Customize the Appearance of the Badge

To alter the appearance of the Badges, use the ThemeColor, FillMode, Rounded, and Size methods when using the HtmlHelper version of the component and the theme-color, fill-mode, rounded, and size attributes when using the TagHelper configuration.

    @using Kendo.Mvc.UI

    @(Html.Kendo().AppBar()
        .Name("appbar")
        .ThemeColor(AppBarThemeColor.Dark)
        .HtmlAttributes(new { style = "height: 50px;"})
        .Items(items =>
        {
            items.Add().Template(Html.Kendo().Template()
                .AddHtml("<span class='k-icon k-i-cart'>")
                .AddComponent(badge => badge
                    .Badge()
                        .Name("shoppingCartBadge")
                        .Text("+10")
                        .Position(BadgePosition.Outside)
                        .Align(BadgeAlign.TopStart)
                        .ThemeColor(BadgeColor.Warning)
                        .FillMode(BadgeFill.Solid)
                        .Rounded(Rounded.Medium)
                        .Size(BadgeSize.Small)
                )
                .AddHtml("</span>")
            )
            .Type(AppBarItemType.ContentItem);
        })
    )

    @addTagHelper *, Kendo.Mvc

    <kendo-appbar name="appbar" theme-color="AppBarThemeColor.Dark" style="height: 50px;">
        <items>
            <appbar-item type="AppBarItemType.ContentItem">
                <template>
                    <span class='k-icon k-i-cart'>
                        <kendo-badge name="shoppingCartBadge" 
                            text="+10" 
                            position="BadgePosition.Outside"
                            align="BadgeAlign.TopStart"
                            theme-color="BadgeColor.Warning"
                            fill-mode="BadgeFill.Solid"
                            rounded="Rounded.Medium"
                            size="BadgeSize.Small">
                        </kendo-badge>
                    </span>
                </template>
            </appbar-item>
        </items>
    </kendo-appbar>

5. (Optional) Reference Existing Badge Instances

You can reference the Badge instances that you have created and build on top of their existing configuration:

Use the Name() option of the component to establish a reference.

    <script>
        $(document).ready(function() {
            var badgeReference = $("#messagesBadge").data("kendoBadge"); // badgeReference is a reference to the existing Badge instance of the helper.
        });
    </script>

Use the Badge client-side API to control the behavior of the widget. In this example, you will use the text method to change the text of the Badge dynamically (for example, when a button is clicked).

    @(Html.Kendo().Button()
        .Name("btn")
        .Content("Update messages Badge")
        .Events(ev => ev.Click("onBtnClick")))

    <script>
        function onBtnClick() {
            var badgeReference = $("#messagesBadge").data("kendoBadge");
            badgeReference.text("+1");
        }
    </script>

    @addTagHelper *, Kendo.Mvc

    <kendo-button name="btn" on-click="onBtnClick">
        Update messages Badge
    </kendo-button>

    <script>
        function onBtnClick() {
            var badgeReference = $("#messagesBadge").data("kendoBadge");
            badgeReference.text("+1");
        }
    </script>

For more information on referencing specific helper instances, see the Methods and Events article.

Explore this Tutorial in REPL

You can continue experimenting with the code sample above by running it in the Telerik REPL server playground:

Getting Started with the Badge

Prerequisites

1. Prepare the CSHTML File

2. Initialize the Badge

3. Integrate Badges into UI Components

4. Customize the Appearance of the Badge

5. (Optional) Reference Existing Badge Instances

Explore this Tutorial in REPL

Next Steps

See Also

Getting Started

Support Resources

Community