MutationRecord: target property

The MutationRecord read-only property target is the target (i.e. the mutated/changed node) of a mutation observed with a MutationObserver.

Value

The Node that the mutation affected.

  • If the record's type is attributes, this is the Element whose attributes changed.
  • If the record's type is characterData, this is the CharacterData node.
  • If the record's type is childList, this is the Node whose children changed.

Examples

Logging the target of a mutation

In the following example, there are two divs: a red div (#red-div) and a blue div (#blue-div), inside a container div #container. A MutationObserver is created to observe the container. The observer is observing changes to the childlist, and also has subtree: true so it will observe changes to the children of the container's children.

The observer callback logs the target of the mutation record. When we add nodes to the #red-div or the #blue-div, the target will be the #red-div or the #blue-div, respectively.

HTML

html

<pre id="log">Target of mutation:</pre>
<button id="add-nodes-to-red-div">Add a node to red div</button>
<button id="add-nodes-to-blue-div">Add a node to blue div</button>
<button id="reset">Reset</button>
<div id="container">
  <div id="red-div"></div>
  <div id="blue-div"></div>
</div>

JavaScript

js

const container = document.querySelector("#container");
const redDiv = document.querySelector("#red-div");
const blueDiv = document.querySelector("#blue-div");
const addToRed = document.querySelector("#add-nodes-to-red-div");
const addToBlue = document.querySelector("#add-nodes-to-blue-div");
const reset = document.querySelector("#reset");
const log = document.querySelector("#log");

addToRed.addEventListener("click", () => {
  const newPara = document.createElement("p");
  newPara.textContent = `Current time: ${Date.now()}`;
  redDiv.appendChild(newPara);
});

addToBlue.addEventListener("click", () => {
  const newPara = document.createElement("p");
  newPara.textContent = `Current time: ${Date.now()}`;
  blueDiv.appendChild(newPara);
});

reset.addEventListener("click", () => self.location.reload());

function logMutationTarget(records) {
  for (const record of records) {
    log.textContent = `Target of mutation: ${record.target.id}`;
  }
}

const observer = new MutationObserver(logMutationTarget);
observer.observe(container, { childList: true, subtree: true });

Result

Specifications

Specification
DOM Standard
# ref-for-dom-mutationrecord-target②

Browser compatibility

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