MutationEvent
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.
The MutationEvent
interface provides event properties that are specific to modifications to the Document Object Model (DOM) hierarchy and nodes.
Note: Using mutation events is problematic:
- Their design is flawed.
- Adding DOM mutation listeners to a document profoundly degrades the performance of further DOM modifications to that document (making them 1.5 - 7 times slower!). Moreover, removing the listeners does not reverse the damage.
- They have poor cross-browser compatibility: Safari doesn't support
DOMAttrModified
(see WebKit bug 8191) and Firefox doesn't support mutation name events (likeDOMElementNameChanged
andDOMAttributeNameChanged
).
They have been deprecated in favor of mutation observers. Consider using these instead.
Instance properties
This interface also inherits properties from its parent UIEvent
, and indirectly from Event
.
MutationEvent.attrChange
Read only Deprecated-
Indicates what kind of change triggered the
DOMAttrModified
event. It can beMODIFICATION
(1
),ADDITION
(2
) orREMOVAL
(3
). It has no meaning for other events and is then set to0
. MutationEvent.attrName
Read only Deprecated-
Indicates the name of the node affected by the
DOMAttrModified
event. It has no meaning for other events and is then set to the empty string (""
). MutationEvent.newValue
Read only Deprecated-
In
DOMAttrModified
events, contains the new value of the modifiedAttr
node. InDOMCharacterDataModified
events, contains the new value of the modifiedCharacterData
node. In all other cases, returns the empty string (""
). MutationEvent.prevValue
Read only Deprecated-
In
DOMAttrModified
events, contains the previous value of the modifiedAttr
node. InDOMCharacterDataModified
events, contains previous new value of the modifiedCharacterData
node. In all other cases, returns the empty string (""
). -
Indicates the node related to the event, like the changed node inside the subtree for
DOMSubtreeModified
.
Instance methods
MutationEvent.initMutationEvent()
Deprecated-
Constructor method that returns a new
MutationEvent
configured with the parameters given.
Mutation events list
The following is a list of all mutation events:
DOMAttrModified
(Not supported by Safari)DOMAttributeNameChanged
(Not supported by Firefox)DOMCharacterDataModified
DOMElementNameChanged
(Not supported by Firefox)DOMNodeInserted
DOMNodeInsertedIntoDocument
DOMNodeRemoved
DOMNodeRemovedFromDocument
DOMSubtreeModified
Examples
You can register a listener for mutation events using EventTarget.addEventListener()
as follows:
js
element.addEventListener(
"DOMNodeInserted",
(event) => {
// …
},
false
);
Specifications
Specification |
---|
UI Events # interface-mutationevent |
Browser compatibility
BCD tables only load in the browser