Web/API/Element/part

The part property of the Element interface represents the part identifier(s) of the element (i.e. set using the part attribute), returned as a DOMTokenList. These can be used to style parts of a shadow DOM, via the ::part pseudo-element.

Syntax

let elementPartList = element.part

Examples

The following excerpt is from our [[../../../../../../../mdn.github.io/web-components-examples/shadow-part/index|shadow-part]] example. Here the part attribute is used to find the shadow parts, and the part property is then used to change the part identifiers of each tab so the correct styling is applied to the active tab when tabs are clicked.

let tabs = [];
let children = this.shadowRoot.children;

for(let elem of children) {
  if(elem.getAttribute('part')) {
    tabs.push(elem);
  }
}

tabs.forEach((tab) => {
  tab.addEventListener('click', (e) => {
    tabs.forEach((tab) => {
      tab.part = 'tab';
    })
    e.target.part = 'tab active';
  })

  console.log(tab.part);
})

Specifications

Specification	Status	Comment
Shadow PartsThe definition of 'Element.part' in that specification.	Working Draft

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`part`	Chrome Full support Yes	Edge Full support 79	Firefox Full support 71 Disabled' Full support 71 Disabled' Disabled' From version 71: this feature is behind the `layout.css.shadow-parts.enabled` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	IE No support No	Opera Full support Yes	Safari Full support 13.1	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android No support No	Opera Android ?	Safari iOS Full support 13.4	Samsung Internet Android Full support Yes

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown
User must explicitly enable this feature.': User must explicitly enable this feature.