Blazor Rating Overview

    The Ignite UI for Blazor Rating component allows users to view and provide feedback.

    Before using the IgbRating, you need to register it as follows:

    // in Program.cs file

builder.Services.AddIgniteUIBlazor(typeof(IgbRatingModule));

    You will also need to link an additional CSS file to apply the styling to the IgbRating component. The following needs to be placed in the wwwroot/index.html file in a Blazor Web Assembly project or the Pages/_Host.cshtml file in a Blazor Server project:

    <link href="_content/IgniteUI.Blazor/themes/light/bootstrap.css" rel="stylesheet" />

    The simplest way to start using the IgbRating is as follows:

    <IgbRating></IgbRating>

    This will create a five-star rating component that can be used to input and read data from.

    Using Custom Symbols

    The IgbRating component allows you to use custom symbols in place of the default star symbols. If you want to use a different symbol, like SVG, icon or another unicode symbol, you should place IgbRatingSymbol components between the opening and closing brackets of the IgbRating:

    <IgbRating>
  <IgbRatingSymbol> <div>💙</div> <div slot="empty">💙</div> </IgbRatingSymbol>
  <IgbRatingSymbol> <div>💙</div> <div slot="empty">💙</div> </IgbRatingSymbol>
  <IgbRatingSymbol> <div>💙</div> <div slot="empty">💙</div> </IgbRatingSymbol>
  <IgbRatingSymbol> <div>💙</div> <div slot="empty">💙</div> </IgbRatingSymbol>
  <IgbRatingSymbol> <div>💙</div> <div slot="empty">💙</div> </IgbRatingSymbol>
</IgbRating>

    The number of rating symbols between the opening and closing brackets of the rating component determines the max value.

    Single Selection

    The Ignite UI for Blazor Rating component has a single selection mode that allows users to provide different icons/elements for the different rating values. In this case, only one of the icons/elements can be selected and reflect the feedback given by the user.

    <IgbRating>
  <IgbRatingSymbol> <div>😣</div> <div slot="empty">😣</div> </IgbRatingSymbol>
  <IgbRatingSymbol> <div>😣</div> <div slot="empty">😣</div> </IgbRatingSymbol>
  <IgbRatingSymbol> <div>😣</div> <div slot="empty">😣</div> </IgbRatingSymbol>
  <IgbRatingSymbol> <div>😣</div> <div slot="empty">😣</div> </IgbRatingSymbol>
  <IgbRatingSymbol> <div>😣</div> <div slot="empty">😣</div> </IgbRatingSymbol>
</IgbRating>

    Keep in mind that the step attribute doesn't work with single selection mode.

    Empty & Selected

    The Ignite UI for Blazor Rating component allows users to use different icons/elements for the empty and the selected state of a single rating value. It is mandatory to provide 2 icons for each slot (empty and full) when declaring a symbol, even if they are the same. For instance:

    <IgbRatingSymbol>
  <IgbIcon Collection="material" IconName="bandage"></IgbIcon>
  <IgbIcon Collection="material" IconName="bacteria" slot="empty"></IgbIcon>
</IgbRatingSymbol>

    Configuration

    Single

    Turns on the Single visual mode for the rating. Useful when using symbols that communicate unique values, like feedback emoji faces.

    Value

    The Value attribute sets the current value of the component.

    Label

    The Label attribute allows setting the label value of the rating component.

    Value Format

    A format string which sets aria-valuetext. All instances of it will be replaced with the current value of the control. Important for screen-readers and useful for localization.

    Max Value

    The Max attribute sets the maximum allowed value of the rating component.

    Step

    The Step attribute sets the allowed fraction of steps between two symbols. Useful when splitting the rating symbols in halves.

    Hover Preview

    The HoverPreview attribute makes the component show the possible outcome of user selection on hover. It is useful when you want to give instant feedback about what the selected value could be.

    Read-Only

    The ReadOnly attribute allows the users to set the IgbRating in read-only mode. This attribute is useful when you want to use the component for information purposes only.

    Disabled

    The Disabled attribute disables the component, making it impossible to select a value using the mouse or keyboard.

    Methods

    Step Up

    The StepUp method increments the value of the component by n steps. Determined by the step factor.

    Step Down

    The StepDown method decrements the value of the component by n steps. Determined by the step factor.

    Events

    The IgbRating component emits two separate events - Hover and Change.

    Hover Event

    The Hover event is fired when hovering over a symbol. It provides the value of the symbol under the mouse cursor. Useful for creating custom value labels and readouts.

    Change Event

    The Change event is fired when the selected value changes.

    Styling

    The IgbRating component exposes CSS parts for almost all of its inner elements. The following table lists all of the exposed CSS parts:

    Name Description
    base The main wrapper which holds all of the rating elements.
    label The label part.
    value-label The value label part.
    symbols A wrapper for all rating symbols.
    symbol The part of the encapsulated default symbol.
    full The part of the encapsulated full symbols.
    empty The part of the encapsulated empty symbols. 
    igc-rating::part(full) {
  color: var(--ig-primary-500)
}

igc-rating::part(empty) {
  color: var(--ig-secondary-200);
}

    API Reference

    Additional Resources