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Observer (engine/view/observer)



Abstract base observer class. Observers are classes which listen to DOM events, do the preliminary processing and fire events on the Document objects. Observers can also add features to the view, for instance by updating its status or marking elements which need refresh on DOM events.



  • document : Document


    Reference to the Document object.

  • isEnabled : Boolean


    State of the observer. If it is disabled events will not be fired.

  • view : View


    Instance of the view controller.


  • constructor( view )

    Creates an instance of the observer.


    view : View
  • destroy()

    Disables and destroys the observer, among others removes event listeners created by the observer.

  • disable()

    Disables the observer. This method is called before rendering to prevent firing events during rendering.

  • enable()

    Enables the observer. This method is called when the observer is registered to the View and after rendering (all observers are disabled before rendering).

    A typical use case for disabling observers is that mutation observers need to be disabled for the rendering. However, a child class may not need to be disabled, so it can implement an empty method.

  • observe( domElement, name )

    Starts observing the given root element.


    domElement : HTMLElement
    name : String

    The name of the root element.