class

MutationObserver

@Js
class MutationObserver : Obj

MutationObserver invokes a callback when DOM modifications occur.

constructors make

Constructor

methods disconnect

Disconnect this observer from receiving DOM mutation events

takeRecs

Empties this observers's record queue and returns what was in there

observe

Register to receive DOM mutation events for given node

disconnect This disconnect()

Disconnect this observer from receiving DOM mutation events.

make new make(|MutationRec[]| callback)

Constructor.

observe This observe(Elem target, Str:Obj opts)

Register to receive DOM mutation events for given node. At least one option is required:

  • "childList": true to observe node additions and removals on target (including text nodes)
  • "attrs": true to observe target attribute mutations
  • "charData": true to observe target data mutation
  • "subtree": true to observe target and target's descendant mutations
  • "attrOldVal": true to capture attribute value before mutation (requires "attrs":'true')
  • "charDataOldVal": true to capture target's data before mutation (requires "charData":'true')
  • "attrFilter": Str[] whitelist of attribute names to observe (requires "attrs":'true')

takeRecs MutationRec[] takeRecs()

Empties this observers's record queue and returns what was in there.

Haxall 4.0.5 ∙ 24-Feb-2026 14:33 EST