Getting Started with the Rating

This tutorial explains how to set up the Telerik UI for ASP.NET Core Rating and goes through the steps in the configuration of the component.

You will declare the Rating component. Then, you will configure the range of the Rating. Next, you'll set a default value and configure a label by using Kendo Templates. Finally, you will learn to handle the JavaScript events of the Rating and how to access client-side reference of the component.

After completing this guide, you will achieve the following results:

Prerequisites

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

• To create a new pre-configured project for the Telerik UI for ASP.NET Core components, you can use 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 document by adding the desired HTML elements like headings, divs, paragraphs, and others.

2. Initialize the Rating

Use the Rating HtmlHelper or TagHelper to configure the component.

• Use the Name() configuration method to assign a name to the instance of the helper—this is mandatory as its value is used for the id and the name attributes of the Rating element.
• Configure the range of the Rating with the Min and Max properties, and set a default Value.
• Use a Kendo Template to customize the Label of the component.

    @using Kendo.Mvc.UI

    @(Html.Kendo().Rating()
        .Name("ratingLabelTemplate")
        .Min(1)
        .Max(6)
        .Value(3)
        .Label(l => l.Template("<span>#=value# out of #=maxValue#</span>"))
    )

    @addTagHelper *, Kendo.Mvc

    <kendo-rating min="1"
                  max="6"
                  value="3"
                  name="ratingLabelTemplate">
        <label template="<span>#=value# out of #=maxValue#</span>" />
    </kendo-rating>

3. Handle the Rating Events

The Rating exposes a Change event that you can handle and assign specific functions to the component. In this tutorial, you will use the Change event to log a message in the browser's console when value of the Rating changes.

    @using Kendo.Mvc.UI

    @(Html.Kendo().Rating()
        .Name("ratingLabelTemplate")
        .Min(1)
        .Max(6)
        .Value(3)
        .Label(l => l.Template("<span>#=value# out of #=maxValue#</span>"))
        .Events(e=>e.Change("onChange"))
    )
    </div>

    @addTagHelper *, Kendo.Mvc


    <kendo-rating min="1"
                  max="6"
                  value="3"
                  name="ratingLabelTemplate">
                  on-change="onChange">
        <label template="<span>#=value# out of #=maxValue#</span>" />
    </kendo-rating>

    function onChange(e){
        console.log(e.newValue)
    }

(Optional) Reference Existing Rating Instances

Referencing existing component instances allows you to build on top of their configuration. To reference an existing Rating instance, use the jQuery.data() method. Once a reference is established, use the Rating client-side API to control its behavior.

1. Use the id attribute of the component instance to establish a reference.

       <script>
           var ratingReference = $("#ratingExample").data("kendoRating"); // ratingReference is a reference to the existing instance of the helper.
       </script>
   

2. Use the Rating client-side API to control the behavior of the widget. In this example, you will see how to adjust the value of Rating programmatically.

       <script>
           var rating = $("#trip").data("kendoRating");        
           rating.value(5);
       </script>
   

Explore this Tutorial in REPL

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

• Sample code with the Rating HtmlHelper
• Sample code with the Rating TagHelper

Next Steps

• Handling the Rating Events
• Controlling the Precision of the Rating
• Using the Rating Templates

See Also

• Using the API of the Rating for ASP.NET Core (Demo)
• Client-Side API of the Rating
• Server-Side API of the Rating
• Knowledge Base Section