Node.isConnected

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.

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 in the case of a shadow DOM.

Синтаксис

var isItConnected = nodeObjectInstance.isConnected

Return value

A Boolean 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

Совместимость с браузерами

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