Node.isConnected

The isConnected read-only property of the Node interface returns a boolean indicating whether the Node is connected (directly or indirectly) to the context object, for example the Document object in the case of the normal DOM, or the ShadowRoot (en-US) in the case of a shadow DOM.

Синтаксис

var isItConnected = nodeObjectInstance.isConnected

Return value

A Boolean (en-US) that is true if the node is connected to its relevant context object, and false if not.

Пример

Стандартный DOM пример:

let test = document.createElement("p");
console.log(test.isConnected); // returns false
document.body.appendChild(test);
console.log(test.isConnected); // returns true

A shadow DOM example:

// Create a shadow root
var shadow = this.attachShadow({ mode: "open" });

// Create some CSS to apply to the shadow dom
var style = document.createElement("style");
console.log(style.isConnected); // returns false

style.textContent =
  ".wrapper {" +
  "position: relative;" +
  "}" +
  ".info {" +
  "font-size: 0.8rem;" +
  "width: 200px;" +
  "display: inline-block;" +
  "border: 1px solid black;" +
  "padding: 10px;" +
  "background: white;" +
  "border-radius: 10px;" +
  "opacity: 0;" +
  "transition: 0.6s all;" +
  "position: absolute;" +
  "bottom: 20px;" +
  "left: 10px;" +
  "z-index: 3;" +
  "}" +
  // attach the created style element to the shadow dom

  shadow.appendChild(style);
console.log(style.isConnected); // returns true

Спецификация

Specification
DOM Standard # ref-for-dom-node-isconnected①

Поддержка Браузерами

BCD tables only load in the browser