diff --git a/source b/source index 60dd4e6a220..e0e6542114b 100644 --- a/source +++ b/source @@ -67033,24 +67033,28 @@ customElements.define("x-foo", class extends HTMLElement { data-x="concept-custom-element-definition-lifecycle-callbacks">lifecycle callbacks with key callbackName.

-

  • If callback is null, then return

    • -
  • -

    If callbackName is "attributeChangedCallback", then:

    +

    If callback is non-null, then:

      -

    1. Let attributeName be the first element of args.

      2. +
    2. +

      If callbackName is "attributeChangedCallback", then:

      + +
        +

      1. Let attributeName be the first element of args.

        2. -

      2. If definition's observed attributes does - not contain attributeName, then return.

        3. +

      3. If definition's observed attributes + does not contain attributeName, then return.

        4. +
      +
      3. + +

    3. Add a new callback reaction to element's custom element + reaction queue, with callback function callback and arguments + args.

    • -

  • Add a new callback reaction to element's custom element - reaction queue, with callback function callback and arguments - args.

    • -

  • Enqueue an element on the appropriate element queue given element.