Rating

<cs-rating>

Stable

Since 0.1

Ratings display a numeric score as a row of selectable symbols, typically stars. Use them to capture quick feedback or show an average rating for a product or piece of content.

<cs-rating label="Rating"></cs-rating>

This component works with standard <form> elements. See form controls for form submission and client-side validation.

Examples

Label

Ratings are usually identified by context, so the label isn’t displayed. Always provide one with the label attribute so assistive devices can announce the control.

<cs-rating label="Rate this component"></cs-rating>

Disabled

Use the disabled attribute to disable the rating.

<cs-rating label="Rating" disabled value="3"></cs-rating>

Readonly

Use the readonly attribute to display a rating that users can’t change. Unlike disabled, a readonly rating still submits its value with the form.

<cs-rating label="Rating" readonly value="3"></cs-rating>

Size

Use the size attribute to change the rating’s size.

<div class="cs-stack">
  <cs-rating label="Extra small" size="xs"></cs-rating>
  <cs-rating label="Small" size="s"></cs-rating>
  <cs-rating label="Medium" size="m"></cs-rating>
  <cs-rating label="Large" size="l"></cs-rating>
  <cs-rating label="Extra large" size="xl"></cs-rating>
</div>

For finer control, set the font-size property directly.

<cs-rating label="Rating" style="font-size: 3rem;"></cs-rating>

Max Value

Ratings go from 0 to 5 by default. Use the max attribute to change the highest possible value.

<cs-rating label="Rating" max="3"></cs-rating>

Precision

Use the precision attribute to let users select fractional ratings, such as half stars.

<cs-rating label="Rating" precision="0.5" value="2.5"></cs-rating>

Custom Icons

Pass a function to the getSymbol property to render a custom symbol in place of the default star.

<cs-rating label="Rating" class="rating-hearts" style="--symbol-color-active: #ff4136;"></cs-rating>

<script type="module">
  const rating = document.querySelector('.rating-hearts');

  await customElements.whenDefined('cs-rating');
  await rating.updateComplete;

  rating.getSymbol = () => '<cs-icon name="favorite" variant="fill"></cs-icon>';
</script>

Value-Based Icons

The getSymbol function receives the symbol’s value and whether it’s currently selected, so you can render different icons across the scale.

<cs-rating label="Rating" class="rating-emojis"></cs-rating>

<script type="module">
  const rating = document.querySelector('.rating-emojis');

  await customElements.whenDefined('cs-rating');
  await rating.updateComplete;

  rating.getSymbol = (value, isSelected) => {
    const icons = ['sentiment_very_dissatisfied', 'sentiment_dissatisfied', 'sentiment_neutral', 'sentiment_satisfied', 'sentiment_very_satisfied'];
    return `<cs-icon name="${icons[value - 1]}"></cs-icon>`;
  };
</script>

Detecting Hover

Use the cs-hover event to react as the user hovers over (or touches and drags across) the rating, before they commit to a value.

The event’s detail carries phase and value. The phase property reports when hovering starts, moves to a new value, and ends. The value property is what the rating would become if the user committed to the hovered symbol.

<div class="detect-hover">
  <cs-rating label="Rating"></cs-rating>
  <span></span>
</div>

<script>
  const rating = document.querySelector('.detect-hover > cs-rating');
  const span = rating.nextElementSibling;
  const terms = ['No rating', 'Terrible', 'Bad', 'OK', 'Good', 'Excellent'];

  rating.addEventListener('cs-hover', event => {
    span.textContent = terms[event.detail.value];

    // Clear feedback when hovering stops
    if (event.detail.phase === 'end') {
      span.textContent = '';
    }
  });
</script>

<style>
  .detect-hover span {
    position: relative;
    top: -4px;
    left: 8px;
    border-radius: var(--cs-border-radius-m);
    background: var(--cs-color-neutral-fill-loud);
    color: var(--cs-color-neutral-on-loud);
    text-align: center;
    padding: 4px 6px;
  }

  .detect-hover span:empty {
    display: none;
  }
</style>

Required

Use the required attribute to make the rating mandatory. The form won’t submit until the user selects a value.

<form class="rating-required">
  <cs-rating label="Rating" required></cs-rating>
  <br /><br />
  <cs-button appearance="filled" type="submit">Submit</cs-button>
</form>

<script type="module">
  const form = document.querySelector('.rating-required');

  await Promise.all([customElements.whenDefined('cs-button'), customElements.whenDefined('cs-rating')]).then(() => {
    form.addEventListener('submit', event => {
      event.preventDefault();
      alert('All fields are valid!');
    });
  });
</script>

Custom Validity

Use the setCustomValidity() method to set a custom validation message. This prevents the form from submitting and makes the browser display your message. Pass an empty string to clear the error.

<form class="rating-custom-validity">
  <cs-rating label="Rating"></cs-rating>
  <br /><br />
  <cs-button appearance="filled" type="submit">Submit</cs-button>
</form>

<script type="module">
  const form = document.querySelector('.rating-custom-validity');
  const rating = form.querySelector('cs-rating');
  const errorMessage = 'Please rate at least 3 stars!';

  customElements.whenDefined('cs-rating').then(async () => {
    await rating.updateComplete;
    rating.setCustomValidity(errorMessage);
  });

  rating.addEventListener('change', () => {
    rating.setCustomValidity(rating.value >= 3 ? '' : errorMessage);
  });

  await Promise.all([customElements.whenDefined('cs-button'), customElements.whenDefined('cs-rating')]).then(() => {
    form.addEventListener('submit', event => {
      event.preventDefault();
      alert('All fields are valid!');
    });
  });
</script>

Form Submission

Ratings work in forms just like native form controls. The rating’s name and value are included in the form data on submit.

  
  Submit
  Reset

<form class="rating-form-submission" action="about:blank" method="get" target="_blank">
  <cs-rating name="rating" label="How would you rate your experience?" required></cs-rating>
  <br /><br />
  <cs-button type="submit">Submit</cs-button>
  <cs-button appearance="filled" type="reset" variant="neutral">Reset</cs-button>
</form>

API

Importing

If you're using the autoloader or a hosted project, components load on demand — no manual import needed. To cherry-pick this component, use one of the following snippets.

npm

Self-Hosted

React

import '@cruglobal/cornerstone-components/components/rating/rating.js';

import './cornerstone/components/rating/rating.js';

import CsRating from '@cruglobal/cornerstone-components/react/rating/index.js';

Attributes & Properties

Learn more about attributes and properties.

Property	Attribute	Description	Type	Default	Reflects
`defaultValue`	`default-value`	The default value of the form control. Used to reset the rating to its initial value.	`number`	`0`	—
`disabled`	`disabled`	Disables the rating.	`boolean`	`false`	—
`form`	—	By default, form controls are associated with the nearest containing `<form>` element. This attribute allows you to place the form control outside of a form and associate it with the form that has this `id`. The form must be in the same document or shadow root for this to work.	`HTMLFormElement \| null`	—	—
`getSymbol`	`getSymbol`	A function that customizes the symbol to be rendered. The first and only argument is the rating's current value. The function should return a string containing trusted HTML of the symbol to render at the specified value. Works well with `<cs-icon>` elements.	`(value: number, isSelected: boolean) => string`	—	—
`label`	`label`	A label that describes the rating to assistive devices.	`string`	`''`	—
`max`	`max`	The highest rating to show.	`number`	`5`	—
`name`	`name`	The name of the rating, submitted as a name/value pair with form data.	`string \| null`	`null`	Yes
`precision`	`precision`	The precision at which the rating will increase and decrease. For example, to allow half-star ratings, set this attribute to `0.5`.	`number`	`1`	—
`readonly`	`readonly`	Makes the rating readonly.	`boolean`	`false`	Yes
`required`	`required`	Makes the rating a required field.	`boolean`	`false`	Yes
`size`	`size`	The component's size.	`'xs' \| 's' \| 'm' \| 'l' \| 'xl'`	`'m'`	Yes
`validationTarget`	—	Override this to change where constraint validation popups are anchored.	`undefined \| HTMLElement`	—	—
`validators`	—	Validators are static because they have `observedAttributes`, essentially attributes to "watch" for changes. Whenever these attributes change, we want to be notified and update the validator.	`Validator[]`	`[]`	—
`value`	`value`	The current rating.	`number`	`0`	—

Methods

Learn more about methods.

Name	Description	Arguments
`formStateRestoreCallback()`	Called when the browser is trying to restore element’s state to state in which case reason is "restore", or when the browser is trying to fulfill autofill on behalf of user in which case reason is "autocomplete". In the case of "restore", state is a string, File, or FormData object previously set as the second argument to setFormValue.	`state: string \| File \| FormData \| null, reason: 'autocomplete' \| 'restore'`
`resetValidity()`	Reset validity is a way of removing manual custom errors and native validation.	—
`setCustomValidity()`	Do not use this when creating a "Validator". This is intended for end users of components. We track manually defined custom errors so we don't clear them on accident in our validators.	`message: string`

Events

Learn more about events.

Name	Description
`change`	Emitted when the rating's value changes.
`cs-hover`	Emitted when the user hovers over a value. The `phase` property indicates when hovering starts, moves to a new value, or ends. The `value` property tells what the rating's value would be if the user were to commit to the hovered value.
`cs-invalid`	Emitted when the form control has been checked for validity and its constraints aren't satisfied.

CSS Custom Properties

Learn more about CSS custom properties.

Name	Description	Default
`--symbol-color`	The inactive color for symbols.	—
`--symbol-color-active`	The active color for symbols.	—
`--symbol-spacing`	The spacing to use around symbols.	—

CSS Parts

Learn more about CSS parts.

Name	Description	CSS selector
`rating`	The component's outer wrapper.	`::part(rating)`

Dependencies

This component automatically imports the following elements. Sub-dependencies, if any exist, are included in this list.

<cs-icon>

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