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MutationEvent: attrChange property

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

Non-standard: This feature is not standardized. We do not recommend using non-standard features in production, as they have limited browser support, and may change or be removed. However, they can be a suitable alternative in specific cases where no standard option exists.

The attrChange read-only property of the MutationEvent interface returns a number indicating what kind of change triggered the DOMAttrModified event. The three possible values are MODIFICATION (1), ADDITION (2) or REMOVAL (3). It has no meaning for other events and is then set to 0.

Value

An integer: 0, 1 (MODIFICATION), 2 (ADDITION), or 3 (REMOVAL).

Examples

element.addEventListener(
  "DOMAttrModified",
  (event) => {
    console.log(event.attrChange);
  },
  false,
);

Specifications

This feature does not appear to be defined in any specification.>

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Opera Safari Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet WebView Android WebView on iOS
attrChange 1–127 12–127 1–140 ≤12.1 1–26 18–127 4–140 ≤12.1 1–26 1.0–28.0 4.4–127 1–26

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https://developer.mozilla.org/en-US/docs/Web/API/MutationEvent/attrChange