MutationRecord object

Represents a single mutation that occurred on the element(s) being observed.

Syntax


function mutationObjectCallback(mutationRecordsList) {
  mutationRecordsList.forEach(function(mutationRecord) {
    console.log("Type of mutation: " + mutationRecord.type);
  });
}

DOM Information

Inheritance Hierarchy

The MutationRecord does not inherit from any class or interface.

Members

The MutationRecord object has these types of members:

Properties

Properties

The MutationRecord object has these properties.

Property	Access type	Description
addedNodes	Read-only	Retrieves an array of nodes that were added. The array may be empty.
attributeName	Read-only	Retrieves the name of the attribute that was added, removed, or changed (or null otherwise).
attributeNamespace	Read-only	Retrieves the namespace of the attribute that was added, removed, or changed (or null otherwise).
nextSibling	Read-only	Retrieves the next sibling of the node that was added or removed, or null if none exists (or if MutationRecord.type is not childList)
oldValue	Read-only	Retrieves the previous value of the attribute or characterData that was mutated (or null otherwise)..
previousSibling	Read-only	Retrieves the previous sibling of the node that was added or removed, or null if none exists (or if MutationRecord.type is not childList)
removedNodes	Read-only	Retrieves an array of nodes that were removed. The array may be empty.
target	Read-only	Retrieves the node on which the MutationRecord was logged.
type		Retrieves the type of mutation represented by the MutationRecord.

Remarks

Each MutationObserver instance maintains an array of MutationRecords which is passed as the first parameter whenever the MutationObserver's callback function is invoked.

The MutationObserver's array of MutationRecords will accumulate all relevant changes until the MutationObserver.takeRecords method is called, which empties the queue and returns the records that were previously there.