Table of contents

Appendices

1.4 Event types

Each event is associated with a type, called event type. The event type is composed of a local name and a namespace URI as defined in [Namespaces]. All events defined in this specification use the namespace URI "http://www.w3.org/2001/xml-events".

NOTE: 

As in [DOMCore], DOM Level 3 Events does not perform any URI normalization or canonicalization. The URIs given to the DOM are assumed to be valid (e.g., characters such as white spaces are properly escaped), and no lexical checking is performed. Absolute URI references are treated as strings and compared literally. How relative namespace URI references are treated is undefined. To ensure interoperability only absolute namespace URI references (i.e., URI references beginning with a scheme name and a colon) should be used. Applications that wish to have no namespace should use the value null as the namespaceURI parameter of methods. If they pass an empty string the DOM implementation turns it into a null.

Complete list of event types[top]

Depending on the level of DOM support, or the devices used to display (e.g. screen) or interact with (e.g. mouse, keyboard, touch screen, voice, ...), these event types could be generated by the implementation. When used with an [XML] or [HTML40] application, the specifications of those languages may restrict the semantics and scope (in particular the possible target nodes) associated with an event type. For example, {"http://www.w3.org/2001/xml-events", "click"} can be targeted to all [XHTML10] elements but applet, base, basefont, bdo, br, font, frame, frameset, head, html, iframe, isindex, meta, param, script, style, and title. Refer to the specification defining the language used in order to find those restrictions or to find event types that are not defined in this document.

The following table defines all event types provided in this specification (with the exception of two event types preserved for backward compatibility with [HTML40]). All events will accomplish the capture phase and target phases, but not all of them will accomplish the bubbling phase (see also [DOM event flow]). Some events are not cancelable event (see [Default actions and cancelable events]). Contextual information related to the event type are accessible using DOM interfaces.

The event objects associated with the event types described above may contain context information. Refer to the description of the DOM interfaces for further information.

Compatibility with DOM Level 2 Events[top]

Namespace URIs Were only introduced in DOM Level 3 Events and were not part of DOM Level 2 Events. DOM Level 2 Events methods are namespace ignorant and the event type is only represented by an XML name, specified in the Event.type attribute.

Therefore, while it is safe to use these methods when not dealing with namespaces, using them and the new ones at the same time should be avoided. DOM Level 2 Events methods solely identify events by their Event.type. On the contrary, the DOM Level 3 Events methods related to namespaces, identify attribute nodes by their Event.namespaceURI and Event.type. Because of this fundamental difference, mixing both sets of methods can lead to unpredictable results. For example, using EventTarget.addEventListenerNS, two event listeners (or more) could be registered using the same type and same useCapture values, but different namespaceURIs. Calling EventTarget.removeEventListener with that type and useCapture could then remove any or none of those event listeners. The result depends on the implementation. The only guarantee in such cases is that all methods which access an event listener by its namespaceURI and type will access the same event listener. For instance, EventTarget.removeEventListenerNS removes the event that EventTarget.addEventListenerNS added.

For compatibility reasons, the dispatching of an event will ignore namespace URIs if either the event or the event listener has a null namespace URI. If a DOM Level 2 event (i.e. with a null namespace URI) is dispatched in the DOM tree, all event listeners that match the type will be triggered as described in the [DOM event flow]. If a DOM Level 3 event (i.e. with a namespace URI) is dispatched in the DOM tree, all event listener with the same type and the same or null namespace URI, will be triggered as described in the [DOM event flow].