MutationRecord

A MutationRecord represents an individual DOM mutation. It is the object that is inside the array passed to MutationObserver's callback.

Properties

Property Type Description
MutationRecord.type String Returns "attributes" if the mutation was an attribute mutation,
"characterData" if it was a mutation to a CharacterData node,
and "childList" if it was a mutation to the tree of nodes.
MutationRecord.target Node Returns the node the mutation affected, depending on the MutationRecord.type.
For attributes, it is the element whose attribute changed.
For characterData, it is the CharacterData node.
For childList, it is the node whose children changed.
MutationRecord.addedNodes NodeList Return the nodes added. Will be an empty NodeList if no nodes were added.
MutationRecord.removedNodes NodeList Return the nodes removed. Will be an empty NodeList if no nodes were removed.
MutationRecord.previousSibling Node Return the previous sibling of the added or removed nodes, or null.
MutationRecord.nextSibling Node Return the next sibling of the added or removed nodes, or null.
MutationRecord.attributeName String Returns the local name of the changed attribute, or null.
MutationRecord.attributeNamespace String Returns the namespace of the changed attribute, or null.
MutationRecord.oldValue String

The return value depends on the MutationRecord.type.
For attributes, it is the value of the changed attribute before the change.
For characterData, it is the data of the changed node before the change.
For childList, it is null.

Note: For this to work as expected, attributeOldValue or characterDataOldValue must be set to true in the corresponding parameter of the MutationObserver observe method

Specifications

Specification
DOM Standard
# interface-mutationrecord

Browser compatibility

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