Was macht die Komponente?

Ein Button ist ein interaktives Element, das eine Aktion auslöst, wenn er angeklickt wird.

Wann soll die Komponente eingesetzt werden?

• Um eine primäre oder sekundäre Aktion auf einer Seite auszuführen.
• Um das Absenden von Formularen zu ermöglichen.
• Um Interaktionen, wie das Öffnen von Dialogen oder das Navigieren zu einer anderen Seite, zu ermöglichen.

Regeln

• Ein Button soll klar beschriftet sein und eine eindeutige Aktion beschreiben.
• Vermeide es, mehrere primäre Buttons auf einer Seite zu verwenden; stattdessen sollten sekundäre Buttons oder Links genutzt werden.

Spielwiese

The sbb-button component provides the same functionality as a native <button>
enhanced with the SBB Design in the 'primary' variant.

<sbb-button>Button text</sbb-button>

Slots

The button text is provided via an unnamed slot; the component can optionally display a sbb-icon
at the component start using the iconName property or via custom content using the icon slot.
At least one is mandatory, so you can have a sbb-button with icon only, text only, or with both.

<sbb-button icon-name="info"> Button text </sbb-button>

<sbb-button>
  <sbb-icon slot="icon" name="info"></sbb-icon>
  Button text
</sbb-button>

<sbb-button icon-name="info" aria-label="Click for more information."></sbb-button>

Button properties

The component is internally rendered as a button,
accepting its associated properties (type, name, value and form).

<sbb-button type="submit" name="tickets" form="buy" value="tickets"> Buy tickets </sbb-button>

Style

The component has a negative variant which can be set using the negative property.

There are two different sizes (m and l, which is the default) that can be set using the size property.

The component can be displayed in disabled state using the self-named property.

<sbb-button negative>Button</sbb-button>

<sbb-button size="m">Button</sbb-button>

<sbb-button disabled>Button</sbb-button>

Loading state

The component can be set into a loading state using the loading property.
This should be done by listening to the click event on the button and setting
the loading property to true e.g. when waiting for a response from the server.
After receiving the response, the property should be set back to false.
The loading state will be animated after a delay of 300ms, which can be configured with the
--sbb-button-loading-delay CSS variable.

<sbb-button
  @click="${(e: PointerEvent) =>
  { 
    const button = e.currentTarget as SbbButtonElement;
    button.loading = true;
    setTimeout(() => (button.loading = false), 4000); 
  }}"
>
  Button
</sbb-button>

Focus outline

Please make sure that the focus outline appears in the correct color if the component is used on a dark background.
You can set it by re-defining the CSS var on sbb-button or any parent element:

sbb-button {
  --sbb-focus-outline-color: var(--sbb-focus-outline-color-dark);
}

Accessibility

Use the accessibility properties in case of an icon-only button to describe the purpose of the sbb-button for screen-reader users.

Interactive disabled buttons

Native disabled elements cannot receive focus and do not dispatch any events. This can
be problematic in some cases because it can prevent the app from telling the user why the button is
disabled. Consumers can use the disabledInteractive property to style the button as disabled but allow for
it to receive focus and dispatch events. The button will have aria-disabled="true" for assistive
technology. It is the consumers responsibility to provide a reason for the element being disabled.
This can be achieved by adding an aria-label, aria-labelledby or aria-describedby attribute.

Note: Using the disabledInteractive property can result in buttons that previously prevented
actions to no longer do so, for example a submit button in a form. When using this input, you should
guard against such cases in your component.

Properties

Methods

CSS Properties

Slots