CustomEvent

Constructor

CustomEvent()

Crea un CustomEvent.

Propiedades

CustomEvent.detail Read only

Cualquier dato transmitido al inicializar el evento.

Esta interface hereda las propiedades de su padre, Event:

Event.bubbles Read only

A Boolean indicating whether the event bubbles up through the DOM or not.

Event.cancelBubble

A historical alias to Event.stopPropagation(). Setting its value to true before returning from an event handler prevents propagation of the event.

Event.cancelable Read only

A Boolean indicating whether the event is cancelable.

Event.composed Read only

A Boolean value indicating whether or not the event can bubble across the boundary between the shadow DOM and the regular DOM.

Event.currentTarget Read only

A reference to the currently registered target for the event. This is the object to which the event is currently slated to be sent; it's possible this has been changed along the way through retargeting.

Event.deepPath 

An Array of DOM Nodes through which the event has bubbled.

Event.defaultPrevented Read only

Indicates whether or not event.preventDefault() has been called on the event.

Event.eventPhase Read only

Indicates which phase of the event flow is being processed.

Event.explicitOriginalTarget Read only

The explicit original target of the event (Mozilla-specific).

Event.originalTarget Read only

The original target of the event, before any retargetings (Mozilla-specific).

Event.returnValue

A non-standard alternative (from old versions of Microsoft Internet Explorer) to Event.preventDefault() and Event.defaultPrevented.

Event.scoped Read only

A Boolean indicating whether the given event will bubble across through the shadow root into the standard DOM. This property has been renamed to composed.

Event.srcElement

A non-standard alias (from old versions of Microsoft Internet Explorer) for Event.target.

Event.target Read only

A reference to the target to which the event was originally dispatched.

Event.timeStamp Read only

The time at which the event was created, in milliseconds. By specification, this value is time since epoch, but in reality browsers' definitions vary; in addition, work is underway to change this to be a DOMHighResTimeStamp instead.

Event.type Read only

The name of the event (case-insensitive).

Event.isTrusted Read only

Indicates whether or not the event was initiated by the browser (after a user click for instance) or by a script (using an event creation method, like event.initEvent)

Metodos

CustomEvent.initCustomEvent()

Inicializar un objeto CustomEvent. Si el evento ya ha sido enviado, este metodo no hace nada.

Esta interface hereda los metodos de su padre, Event:

Event.initEvent()

Initializes the value of an Event created. If the event has already being dispatched, this method does nothing.

Event.preventBubble() Obsolete since Gecko 24

Prevents the event from bubbling. Obsolete, use event.stopPropagation instead.

Event.preventCapture() Obsolete since Gecko 24

Obsolete, use event.stopPropagation instead.

Event.preventDefault()

Cancels the event (if it is cancelable).

Event.stopImmediatePropagation()

For this particular event, no other listener will be called. Neither those attached on the same element, nor those attached on elements which will be traversed later (in capture phase, for instance)

Event.stopPropagation()

Stops the propagation of events further along in the DOM.

Event.getPreventDefault()

Non-standard. Returns the value of Event.defaultPrevented. Use Event.defaultPrevented instead.

Especificaciones

Compatibilidad con navegadores

Disparar desde código privileged a código non-privileged

Al disparar un CustomEvent desde un código  privileged (una extensión) a un código non-privileged (una página web),  deben considerarse algunos problemas de seguridad. Firefox y otras aplicaciones Gecko restringen al objeto creado desde un contexto siendo directamente utilizado por otro, el cual automáticamente evitará los agujeros de seguridad, pero estas restricciones también pueden impedir que su código se ejecute como esperaba.

Al crear un objeto CustomEvent, debes crear el objeto desde la misma ventana. El atributo detail de tu CustomEvent estará sujeto a las mismas restricciones. Los valores de String y Array serán legibles sin restricciones por el content, pero los objetos personalizados no lo harán. Al utilizar un objeto personalizado, necesitaras definir que atributos de ese objeto se pueden leer desde la secuencia de comandos de contenido usando  Components.utils.cloneInto().

// doc es una referencia al content del documento
function dispatchCustomEvent(doc) {
  var eventDetail = Components.utils.cloneInto({foo: 'bar'}, doc.defaultView);
  var myEvent = doc.defaultView.CustomEvent("mytype", eventDetail);
  doc.dispatchEvent(myEvent);
}

Pero hay que tener en cuenta que exponer una función permitirá que el script content lo ejecute con privilegios de chrome, lo que puede abrir una vulnerabilidad de seguridad.

Ver también

• Interaction between privileged and non-privileged pages
• Window.postMessage
• Creating and triggering events