W3C

XML Events 2

An Events Syntax for XML

W3C Working Draft 16 February 2007

This version:
http://www.w3.org/TR/2007/WD-xml-events-20070216
Latest version:
http://www.w3.org/TR/xml-events
Previous version:
http://www.w3.org/TR/2003/REC-xml-events-20031014
Diff from previous recommendation:
xml-events-diff.html
Editors:
Shane McCarron, Applied Testing and Technology, Inc.
Mark Birbeck, x-port.net Ltd.
Version 1 Editors:
Shane McCarron, Applied Testing and Technology, Inc.
Steven Pemberton, CWI/W3C®
T. V. Raman, IBM Corporation

Please refer to the errata for this document, which may include some normative corrections.

This document is also available in these non-normative formats: PostScript version, PDF version, ZIP archive, and Gzip'd TAR archive.

The English version of this specification is the only normative version. Non-normative translations may also be available.


Abstract

The XML Events module defined in this specification provides XML languages with the ability to uniformly integrate event listeners and associated event handlers with Document Object Model (DOM) Level 2 event interfaces [DOM2EVENTS]. The result is to provide an interoperable way of associating behaviors with document-level markup.

Status of This Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

This document is a Working Draft. It reflects clarifications and corrections as a result of many years of use by the community. It also includes updated implementations in XML Schema and XML DTD that can readily integrate with the host language's namespace. This document should in no way be considered stable, and should not be normatively referenced for any purposes whatsoever.

Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document has been produced by the W3C HTML Working Group (Members only) as part of the HTML Activity. The goals of the HTML Working Group are discussed in the HTML Working Group charter.

This document is governed by the 24 January 2002 CPP as amended by the W3C Patent Policy Transition Procedure. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

Please report errors in this specification to www-html-editor@w3.org (archive). It is inappropriate to send discussion email to this address. Public discussion may take place on www-html@w3.org (archive).

Contents

1.Introduction

This section is informative.

An event is the representation of some asynchronous occurrence (such as a mouse click on the presentation of the element, or an arithmetical error in the value of an attribute of the element, or any of unthinkably many other possibilities) that gets associated with an element (targeted at it) in an XML document.

In the DOM model of events [DOM2EVENTS], the general behavior is that when an event occurs it is dispatched by passing it down the document tree in a phase called capture to the element where the event occurred (called its target), where it then may be passed back up the tree again in the phase called bubbling. In general an event can be responded to at any element in the path (an observer) in either phase by causing an action, and/or by stopping the event, and/or by cancelling the default action for the event. The following diagram illustrates this:

Event propagation flow diagram
Event flow in DOM2: an event targeted at an element (marked 'target') in the tree passes down the tree from the root to the target in the phase called 'capture'. If the event type allows it, the event then travels back up the tree by the same route in a phase called 'bubbling'. Any node in the route, including the root node and the target, may be an 'observer': that is to say, a handler may be attached to it that is activated when the event passes through in either phase. A handler can only listen for one phase. To listen for both you have to attach two handlers.

An action is some way of responding to an event; a handler is some specification for such an action, for instance using scripting or some other method. A listener is a binding of such a handler to an event targeting some element in a document.

HTML [HTML4] binds events to an element by encoding the event name in an attribute name, such that the value of the attribute is the action for that event at that element. This method has two main disadvantages: firstly it hardwires the events into the language, so that to add a new event, you have to make a change to the language, and secondly it forces you to mix the content of the document with the specifications of the scripting and event handling, rather than allowing you to separate them out. SVG [SVG] uses a similar method.

The process of defining a new version of HTML identified the need for an extensible event specification method. The design requirements were the following:

The DOM specifies an event model that provides the following features:

The elements and attributes defined in this specification are the method of binding a DOM level 2 event at an element to an event handler. They encapsulate various aspects of the DOM level 2 event interface, thereby providing markup-level specification of the actions to be taken during the various phases of event propagation.

This document neither specifies particular events, nor mandates any particular methods of specifying actions. These definitions are left to any markup language using the facilities described here.

2.Conformance Requirements

This section is normative.

The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

2.1.Document Conformance

XML Events is not a stand-alone document type. It is intended to be integrated into other host languages such as XHTML. A conforming XML Events document is a document that requires only the facilities described as mandatory in this specification and the facilities described as mandatory in its host language. Such a document must meet all the following criteria:

  1. The document MUST conform to the constraints expressed in Appendix B - Schema Implementation or Appendix A - DTD Implementation, combined with the constraints expressed in its host language implementation.

  2. If the host language does not incorporate XML Events elements and attributes into its own namespace, the document MUST contain an xmlns declaration for the XML Events namespace [XMLNAMES]. The namespace for XML Events is defined to be http://www.w3.org/2001/xml-events. An example start tag of a root element might look like:

    <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"
          xmlns:ev="http://www.w3.org/2001/xml-events" >
    

    Note that we expect this namespace to revert to the namespace of the previous recommendation once development of this specification is complete.

Chameleon Namespace

This draft alludes to supporting "chameleon" use of event elements and attributes. It is not clear that this is easily supportable by implementors. It may be that these elements and attributes must be in their own namespace.

2.2.Host Language Conformance

When XML Events are included in a host language, all of the facilities required in this specification MUST be included in the host language. In addition, the mandatory elements and attributes defined in this specification MUST be included in the content model of the host language.

2.3.User Agent Conformance

A conforming user agent MUST support all of the features required in this specification.

3.The XML Events Module

This section is normative.

This specification defines a module called XML Events. The XML Events module uses the XML namespace [XMLNAMES] identifier http://www.w3.org/2001/xml-events.

Examples in this document that use the namespace prefix "ev" all assume an xmlns declaration xmlns:ev="http://www.w3.org/2001/xml-events" somewhere suitable in the document involved. All examples are informative.

The remainder of this section describes the elements and attributes in this module, the semantics, and provides an abstract module definition as required in [XHTMLMOD].

The XML Events Module supports the following element and attributes:

Element Attributes Minimal Content Model
listener event (QName),
observer (IDREF),
targetid (IDREF),
handler (URI),
phase ("capture" | "default"*),
propagate ("stop" | "continue"*),
defaultAction ("cancel" | "perform"*),
if (XPathExpression),
while (XPathExpression),
xml:id ([XMLID])
EMPTY

Implementations: DTD, XML Schema

3.1.The listener Element

Element listener supports a subset of the DOM's EventListener interface. It is used to declare event listeners and register them with specific nodes in the DOM, and has the following attributes:

event
The required event attribute specifies the event type for which the listener is being registered.
observer
The optional observer attribute specifies the id of the element with which the event listener is to be registered. If this attribute is not present, the observer is the element that the event attribute is on (see later under "Attaching Attributes Directly to the Observer Element"), or the parent of that element (see later under "Attaching Attributes Directly to the Handler Element").

EDITORS' NOTE: There is a proposal that this attribute should be a URI. This is still under discussion, and we recognise that there may be security issues to resolve. However, if they can be addressed then we generally support this.

targetid
The optional targetid attribute specifies the id of the target element of the event (i.e., the node that caused the event). If this attribute is present, only events that match both the event and targetid attributes will be processed by the associated event handler. Clearly because of the way events propagate, the target element should be a descendent node of the observer element, or the observer element itself.

Use of this attribute requires care; for instance, if you specify

<listener event="click" observer="para1"
     targetid="link1" handler="#clicker"/>

where 'para1' is some ancestor of the following node

<a id="link1" href="doc.html">The <em>draft</em> document</a>

and the user happens to click on the word "draft", the em element, and not the a, will be the target, and so the handler will not be activated; to catch all mouse clicks on the a element and its children, use observer="link1", and no targetid attribute.

handler
The optional handler attribute specifies the URI reference of a resource that defines the action that should be performed if the event reaches the observer. (This specification does not mandate what form that element should take: see further the section "Event Handlers"). If this attribute is not present, the handler is the element that the event attribute is on (see later under "Attaching Attributes Directly to the Handler Element").
phase
The optional phase attribute specifies when (during which DOM 2 event propagation phase) the listener will be activated by the desired event.
capture
Listener is activated during capturing phase.
default
Listener is activated during bubbling or target phase.

The default behavior is phase="default".

Note that not all events bubble, in which case with phase="default" you can only handle the event by making the event's target the observer.

propagate
The optional propagate attribute specifies whether after processing all listeners at the current node, the event is allowed to continue on its path (either in the capture or the bubble phase).
stop
event propagation stops
continue
event propagation continues (unless stopped by other means, such as scripting, or by another listener).

The default behavior is propagate="continue".

defaultAction
The optional defaultAction attribute specifies whether after processing of all listeners for the event, the default action for the event (if any) should be performed or not. For instance, in XHTML the default action for a mouse click on an a element or one of its descendents is to traverse the link.
cancel
if the event type is cancelable, the default action is cancelled
perform
the default action is performed (unless cancelled by other means, such as scripting, or by another listener).

The default value is defaultAction="perform".

Note that not all events are cancelable, in which case this attribute is ignored.

if
The optional if attribute allows a condition to be specified. This condition must be met in order for the event handler to be activated. The condition is specified using an XPath Expression. There is no default value.

This attribute allows event handlers to be specified that respond not just to named events, but to more specific conditions, such as a mouse click with the control key pressed:

<listener event="click" if="event('ctrlKey') = true()"
          observer="para1"
          targetid="link1" handler="#clicker"/>

The event function is described in XPath Event Function.

while
The optional while attribute allows a condition to be specified. This condition must be met in order for the event handler to be activated. The condition is specified using an XPath Expression. There is no default value.

This attribute allows event handlers to be specified that perform their action whilst some condition remains true.

EDITORS' NOTE: Can't think of an example that only makes use of what we have in this spec, i.e., the event() function. We may need to do something like delete a list in XForms.

Note that observer = "<element-id>" and event = "<event-type>" are similar to the begin = "<element-id>.<event-type>" attribute in SMIL EventTiming [SMIL20].

3.1.1.Examples of listener Usage

  1. This example attaches the handler in the element at "#doit" that will get activated when the event called activate occurs on the element with id="button1", or any of its children. The activation will occur during bubbling, or if the event happened on the observer element itself, when the event reaches the element (phase target).

    <listener event="activate" observer="button1" handler="#doit"/>
    
  2. This attaches the handler at #overflow-handler that will get activated when the event overflow occurs on the element with id="expr1" and bubbles up to the element with id="prog1".

    <listener event="overflow" observer="prog1" targetid="expr1"
            handler="#overflow-handler"/>
    
  3. This attaches the handler at #popup that will get activated whenever an activate event occurs at the element with id="embargo" or any of its children. Since it will be activated during the capture phase, and propagation is stopped, this will have the effect (regardless of what the handler does) of preventing any child elements of the embargo element seeing any activate events.

    <listener event="activate" observer="embargo" handler="#popup"
            phase="capture" propagate="stop"/>
    
  4. This attaches a handler from another document.

    <listener event="activate" observer="image1"
        handler="/handlers/events.xml#activate"/>
    

3.2.Attaching Attributes Directly to the Observer Element

All the attributes from the listener element with the exception of id may be used as global attributes, as defined in Namespaces in XML [XMLNAMES], to attach the attributes to other elements.

Note that this means that the listener element is strictly speaking redundant, since the following

<anyelement ev:event="click" ev:observer="button1" ev:handler="#clicker"/>

would have the same effect as

<ev:listener event="click" observer="button1" handler="#clicker"/>

Nonetheless, for utility the listener element has been retained.

If the observer attribute is omitted (but not the handler attribute), then the element that the other attributes are attached to is the observer element.

3.2.1. Examples of Using Attributes Attached to an Observer Element

  1. This first example will attach the handler identified by "#popper" to the a element, and cancel the default action for the event.

    <a href="doc.html" ev:event="activate" ev:handler="#popper"
       ev:defaultAction="cancel">The document</a>
    
  2. This will attach the handler at #handle-overflow for the event overflow to the current element.

    <div ev:event="overflow" ev:handler="#handle-overflow"> ... </div>
    

3.3.Attaching Attributes Directly to the Handler Element

If, when attaching the global attributes to an element, the handler attribute is omitted then the element that the other attributes are attached to is the handler element.

Note that, since the observer and targetid attributes are IDREFs, in this case the handler and observer/target elements must be in the same document (while in other cases, since the handler attribute is a URI, the handler element may be in another document).

If the observer attribute is also omitted, then the parent of the handler element is the observer element.

3.3.1. Examples of Using Attributes Attached to a Handler Element

  1. In this case the element is the handler for the submit event on the element with id="form1".

    <script type="application/x-javascript"
            ev:event="submit" ev:observer="form1">
       return docheck(event);
    </script>
    
  2. In this case the action element is the handler for event q-submit, and the observer is the questionnaire element.

    <questionnaire submissionURL="/q/tally">
        <action ev:event="q-submit">
          ...
        </action>
        ...
     </questionnaire>
    
  3. The script element is the handler for event click; the img element is the observer.

    <img src="button.gif" alt="OK">
        <script ev:event="activate" type="application/x-javascript">
            doactivate(event);
        </script>
    </img>
    
  4. The onevent element is the handler for event enterforward. The card element is the observer.

    <card>
        <onevent ev:event="enterforward">
            <go href="/url"/>
        </onevent>
        <p>
          Hello!
        </p>
    </card>
    
  5. The catch element is the handler for the nomatch event. The observer is the field element.

    <form id="launch_missiles">
      <field name="password">
        <prompt>What is the code word?</prompt>
        <grammar>
          <rule id="root" scope="public">rutabaga</rule>
        </grammar>
        <help>It is the name of an obscure vegetable.</help>
        <catch ev:event="nomatch">
          <prompt>Security violation!</prompt>
          <submit next="apprehend_felon" namelist="user_id"/>
        </catch>
      </field>
      <block>
        <goto next="#get_city"/>
      </block>
    </form>
    
  6. This example shows three handlers for different events. The observer for all three is the secret element.

    <secret ref="/login/password">
        <caption>Please enter your password</caption>
        <info ev:event="help">
            Mail help@example.com in case of problems
        </info>
        <info ev:event="hint">
            A pet's name
        </info>
        <info ev:event="alert">
            This field is required
        </info>
    </secret>
    

3.4.Summary of Observer and Handler Attribute Defaulting

The following table summarizes which elements play the role of observer or handler if the relevant attribute is omitted.

The effect of omitted observer and handler attributes
Handler present Handler omitted
Observer present (As declared) Element is handler
Observer omitted Element is observer Element is handler
Parent is observer

3.5.Event Handlers

This specification does not require an XML application that uses XML Events to use any particular method for specifying handlers. However, the examples, particularly those in the section on attaching the attributes directly to the handler, are intended to give examples of how they could be specified.

It is however recognized that two methods are likely to occur often: scripting (such as XHTML's <script> element) and declarative markup using XML elements (such as WML's <onevent> element). Section 4 of this specification provides markup to support these methods.

3.6.The Basic XML Events Profile

The Basic XML Events Profile allows restrictions on the usage of the XML Events Module in order to make processing easier on small devices.

The Basic Profile allows the following restrictions on the use of listener element and its attributes, and on the use of the attributes from the listener element as global attributes.

  1. External Event Handlers

    The ability to process external event handlers is not required. When the 'handler' attribute on the listener element is used, or when the global 'handler' attribute is used, the handler specified in the value of that attribute should be within the current document.

    For example, the following is allowed:

    <listener event="click" targetid="#button1" handler="#clicker"/>
    

    while the following is not required to be processed:

    <listener event="click" targetid="#button1" handler="doc2.html#clicker"/>
    
  2. Ordering of Event Bindings

    The binding of an event handler to an observer may be required to be lexically before the end of the observer element. In other words, a listener binding to an observer may not occur after the closing tag of the observer element, and an event handler carrying the attributes to bind it to an observer may also not occur after the closing tag of the observer element.

4.The XML Handlers Module

This section is normative.

This specification also defines a module called XML Handlers. The XML Handlers module also uses the XML namespace [XMLNAMES] identifier http://www.w3.org/2001/xml-events.

The purpose of this module is to provide a declarative way to map specific events to a series of one or more actions. Those actions are declared either by the host language (e.g., [XFORMS]) or within the document using the XML Events module above. Implementing actual handlers for the events remains the perview of the host language, supported scripting languages, etc.

The XML Handlers Module supports the following elements and attributes:

Element Attributes Minimal Content Model
action event (QName),
targetid (IDREF),
declare ("declare"),
xml:id ([XMLID])
( action | script | dispatchEvent | addEventListener | removeEventListener | stopPropagation | preventDefault )+
script encoding (Charset),
src (URI),
type (ContentTypes),
xml:id ([XMLID])
PCDATA
dispatchEvent raise (QName),
destid (IDREF),
bubbles ("bubbles"),
cancelable ("cancelable"),
xml:id ([XMLID])
EMPTY
addEventListener event* (QName),
handler* (IDREF),
phase ("capture" | "default"*),
xml:id ([XMLID])
EMPTY
removeEventListener event* (QName),
handler* (IDREF),
phase ("capture" | "default"*),
xml:id ([XMLID])
EMPTY
stopPropagation event* (QName),
xml:id ([XMLID])
EMPTY
preventDefault event* (QName),
xml:id ([XMLID])
EMPTY

Implementations: DTD, XML Schema

4.1.The action Element

The action element is used to group event handler elements (including other action elements) that will act in sequence as handlers for an event. The action element takes the following attributes:

event
The required event attribute specifies the event type this action will handle.
targetid
The optional targetid attribute specifies the id of the target element of the event (i.e., the node that caused the event). If this attribute is present, only events that match both the event and targetid attributes will be processed by the associated event handler. Clearly because of the way events propagate, the target element should be a descendant node of the observer element, or the observer element itself.
declare
When present, this boolean attribute makes the current element (and any elements it may contain) a declaration only.

4.2.The script Element

The script element contains or references scripts that may register one or more event handlers for a document through a scripting language that is supported by the implementation.

The event handler(s) may be defined within the contents of the script element or in an external file. If the src attribute is not set, user agents MUST interpret the contents of the element as the handler. If the src has a URI value, user agents MUST ignore the element's contents and retrieve the handler via the URI.

Note that the encoding attribute refers to the character encoding of the handler designated by the src attribute; it does not concern the content of the script element. Also note that the type attribute can be used to specify a list of available implementations for the script, allowing the user agent to choose among them (see type for more details).

4.3.The dispatchEvent Element

The dispatchEvent element triggers the event identified by the raise attribute. If the destid attribute is specified, it names a specific element to which to dispatch the event. Otherwise the event is just dispatched to the "document" to be handled by any registered listener.

The dispatchEvent element also defines two additional attributes:

bubbles
Optional boolean indicating if this event bubbles as defined in [DOM2EVENTS]. The default value will depend on the actual event being dispatched.
cancelable
Optional boolean indicating if this event is cancelable as defined in [DOM2EVENTS]. The default value will depend on the actual event being dispatched.

4.4.The addEventListener element

This element allows the registration of a listener on a specific event, as defined in [DOM2EVENTS].

4.5.The removeEventListener element

The removeEventListener element de-registers the handler identified by the required handler attribute for the event identified by the required event attribute.

4.6.The stopPropagation element

The stopPropagation element is used to prevent further propagation of an event during event flow. If this method is called by any EventListener the event will cease propagating through the tree. The event will complete dispatch to all listeners on the current EventTarget before event flow stops. This method may be used during any stage of event flow.

4.7.The preventDefault element

If an event is cancelable, the preventDefault method is used to signify that the event is to be canceled, meaning any default action normally taken by the implementation as a result of the event will not occur. If, during any stage of event flow, the preventDefault method is called the event is canceled. Any default action associated with the event will not occur. Calling this method for a non-cancelable event has no effect. Once preventDefault has been called it will remain in effect throughout the remainder of the event's propagation. This method may be used during any stage of event flow.

5.Naming Event Types

This section is informative.

This specification does not normatively specify how language designers should name events (i.e., the values used in the event attribute).

However, future versions of DOM Events are likely to allow namespaced event names, so language designers are advised not to use the colon character ":" in event names.

A number of event types are defined in DOM 3 Events [DOM2EVENTS], to which you should refer for their names and semantics.

6.XPath Expressions

XML Events uses XPath expressions to specify conditionals (if, while). As described in section 1 of [XPATH], each XPath expression is evaluated within a context, which is made up of:

XML Events XPath expressions have no context node, and so the context position is 0 and the context size is 0. There are no variable bindings, and the function library contains the functions described below. It is not necessary to provide namespace declarations.

Host languages that import XML Events may provide a richer context, and MUST specify whether their context is the same as that provided here, or more.

6.1.Function Library

The XPath function library consists of the following functions:

6.1.1.XPath event Function

node-set event(string)

Function event returns the value of a property of the current event object, as determined by the string argument. The value returned will be typed, depending on the property. For example, the MouseEvent interface [DOM2EVENTS] has the attribute shiftKey, which is a boolean. This can be accessed by passing the string value 'shiftKey' to the event function. The result will be an XPath boolean.

A.DTD Implementation

This appendix is normative.

The DTD implementation of XML Events conforms to the requirements defined in [XHTMLMOD]. Consequently, it provides a Qualified Names sub-module, and a module file for the XML Events module defined in this Proposed Recommendation.

A.1.Qualified Names Module

Note that this module defines the parameter entity %xml-events-attrs.qname;. This entity is intended to be used in the attribute lists of elements in any host language that permits the use of event attributes on elements in its own namespace. In this case the Host Language driver should set a parameter entity %XML-EVENTS.prefixed; to INCLUDE and a parameter entity %XML-EVENTS.prefix; to a value that is the prefix for the XML Events attributes.

<!-- ....................................................................... -->
<!-- XML Events Qname Module  ............................................ -->
<!-- file: xml-events-qname-2.mod

     This is XML Events - the Events Module for XML,
     a definition of access to the DOM events model.

     Copyright 2000-2007 W3C (MIT, ERCIM, Keio), All Rights Reserved.

     This DTD module is identified by the PUBLIC and SYSTEM identifiers:

       PUBLIC "-//W3C//ENTITIES XML Events Qnames 2.0//EN"
       SYSTEM "http://www.w3.org/MarkUp/DTD/xml-events-qname-2.mod"

     Revisions:
     (none)
     ....................................................................... -->

<!-- XML Events Qname (Qualified Name) Module

     This module is contained in two parts, labeled Section 'A' and 'B':

       Section A declares parameter entities to support namespace-
       qualified names, namespace declarations, and name prefixing
       for XML Events and extensions.

       Section B declares parameter entities used to provide
       namespace-qualified names for all XML Events element types:

         %listener.qname;   the xmlns-qualified name for <listener>
         ...

     XML Events extensions would create a module similar to this one.
     Included in the XML distribution is a template module
     ('template-qname-2.mod') suitable for this purpose.
-->

<!-- Section A: XML Events XML Namespace Framework :::::::::::::::::::: -->

<!-- 1. Declare a %XML-EVENTS.prefixed; conditional section keyword, used
        to activate namespace prefixing. The default value should
        inherit '%NS.prefixed;' from the DTD driver, so that unless
        overridden, the default behavior follows the overall DTD
        prefixing scheme.
-->
<!ENTITY % NS.prefixed "IGNORE" >
<!ENTITY % XML-EVENTS.prefixed "%NS.prefixed;" >

<!-- 2. Declare a parameter entity (eg., %XML-EVENTS.xmlns;) containing
        the URI reference used to identify the XML Events namespace
-->
<!ENTITY % XML-EVENTS.xmlns  "http://www.w3.org/2001/xml-events" >

<!-- 3. Declare parameter entities (eg., %XML.prefix;) containing
        the default namespace prefix string(s) to use when prefixing
        is enabled. This may be overridden in the DTD driver or the
        internal subset of an document instance. If no default prefix
        is desired, this may be declared as an empty string.

     NOTE: As specified in [XMLNAMES], the namespace prefix serves
     as a proxy for the URI reference, and is not in itself significant.
-->
<!ENTITY % XML-EVENTS.prefix  "" >

<!-- 4. Declare parameter entities (eg., %XML-EVENTS.pfx;) containing the
        colonized prefix(es) (eg., '%XML-EVENTS.prefix;:') used when
        prefixing is active, an empty string when it is not.
-->
<![%XML-EVENTS.prefixed;[
<!ENTITY % XML-EVENTS.pfx  "%XML-EVENTS.prefix;:" >
]]>
<!ENTITY % XML-EVENTS.pfx  "" >

<!-- declare qualified name extensions here ............ -->
<!ENTITY % xml-events-qname-extra.mod "" >
%xml-events-qname-extra.mod;

<!-- 5. The parameter entity %XML-EVENTS.xmlns.extra.attrib; may be
        redeclared to contain any non-XML Events namespace declaration
        attributes for namespaces embedded in XML. The default
        is an empty string.  XLink should be included here if used
        in the DTD.
-->
<!ENTITY % XML-EVENTS.xmlns.extra.attrib "" >


<!-- Section B: XML Qualified Names ::::::::::::::::::::::::::::: -->

<!-- 6. This section declares parameter entities used to provide
        namespace-qualified names for all XML Events element types.
-->

<!ENTITY % xml-events.listener.qname  "%XML-EVENTS.pfx;listener" >


<!ENTITY % xml-handlers.action.qname  "%XML-EVENTS.pfx;action" >
<!ENTITY % xml-handlers.script.qname  "%XML-EVENTS.pfx;script" >
<!ENTITY % xml-handlers.dispatchEvent.qname  "%XML-EVENTS.pfx;dispatchEvent" >
<!ENTITY % xml-handlers.addEventListener.qname  "%XML-EVENTS.pfx;addEventListener" >
<!ENTITY % xml-handlers.removeEventListener.qname  "%XML-EVENTS.pfx;removeEventListener" >
<!ENTITY % xml-handlers.stopPropagation.qname  "%XML-EVENTS.pfx;stopPropagation" >
<!ENTITY % xml-handlers.preventDefault.qname  "%XML-EVENTS.pfx;preventDefault" >


<!-- The following defines a PE for use in the attribute sets of elements in
     other namespaces that want to incorporate the XML Event attributes. Note
     that in this case the XML-EVENTS.pfx should always be defined. -->

<!ENTITY % xml-events.attrs.qname
   "%XML-EVENTS.pfx;event            NMTOKEN      #IMPLIED
    %XML-EVENTS.pfx;observer         IDREF        #IMPLIED
    %XML-EVENTS.pfx;target           IDREF        #IMPLIED
    %XML-EVENTS.pfx;handler          %URI.datatype;        #IMPLIED
    %XML-EVENTS.pfx;phase            (capture|default) #IMPLIED
    %XML-EVENTS.pfx;propagate        (stop|continue) #IMPLIED
    %XML-EVENTS.pfx;defaultAction    (cancel|perform) #IMPLIED
    %XML-EVENTS.pfx;condition        CDATA        #IMPLIED"
    >

<!-- end of xml-events-qname-2.mod -->

A.2.XML Events Module

<!-- ...................................................................... -->
<!-- XML Events Module .................................................... -->
<!-- file: xml-events-2.mod

     This is XML Events - the Events Module for XML.
     a redefinition of access to the DOM events model.

     Copyright 2000-2007 W3C (MIT, ERCIM, Keio), All Rights Reserved.

     This DTD module is identified by the PUBLIC and SYSTEM identifiers:

       PUBLIC "-//W3C//ENTITIES XML Events 2.0//EN"
       SYSTEM "http://www.w3.org/MarkUp/DTD/xml-events-2.mod"

     Revisions:
     (none)
     ....................................................................... -->


<!-- XML Events defines the listener element and its attributes -->

<!ENTITY % xml-events.listener.content "EMPTY" >

<!ELEMENT %xml-events.listener.qname; %xml-events.listener.content;>
<!ATTLIST %xml-events.listener.qname;
    xml:id           ID           #IMPLIED
    event            NMTOKEN      #REQUIRED
    observer         IDREF        #IMPLIED
    targetid         IDREF        #IMPLIED
    handler          %anyURI.datatype;        #IMPLIED
    phase            (capture|default) #IMPLIED
    propagate        (stop|continue) #IMPLIED
    condition        CDATA        #IMPLIED
>

<!-- end of xml-events-2.mod -->

A.3.XML Handlers Module

<!-- ................................................................... -->
<!-- XML Handlers Module ............................................... -->
<!-- file: xml-handlers-2.mod

     This is XML Handlers - the Handlers Module for XML.
     a redefinition of support for handlers of the DOM event model.

     Copyright 2007 W3C (MIT, ERCIM, Keio), All Rights Reserved.

     This DTD module is identified by the PUBLIC and SYSTEM identifiers:

       PUBLIC "-//W3C//ENTITIES XML Handlers 2.0//EN"
       SYSTEM "http://www.w3.org/MarkUp/DTD/xml-handlers-2.mod"

     Revisions:
     (none)
     ....................................................................... -->


<!-- XML Handlers defines the various element and attributes -->

<!ENTITY % xml-handlers.action.content 
    "( %xml-handlers.action.qname; |
       %xml-handlers.script.qname; |
       %xml-handlers.dispatchevent.qname; |
       %xml-handlers.addEventListener.qname; |
       %xml-handlers.removeEventListener.qname; |
       %xml-handlers.stopPropagation.qname; |
       %xml-handlers.preventDefault.qname; |
       %xml-handlers.action.extras; )+ "
>

<!ELEMENT %xml-handlers.action.qname; %xml-handlers.action.content;>
<!ATTLIST %xml-handlers.action.qname;
    xml:id           ID                   #IMPLIED
    event            %QName.datatype;     #IMPLIED
    targetid         IDREF                #IMPLIED
    declare          ( declare )          #IMPLIED
    condition        CDATA                #IMPLIED
    while            CDATA                #IMPLIED
>

<!ENTITY % xml-handlers.script.content "( #PCDATA )" >
<!ELEMENT %xml-handlers.script.qname; %xml-handlers.script.content; >
<!ENTITY % xml-handlers.script.attlist  "INCLUDE" >
<![%xml-handlers.script.attlist;[
<!ATTLIST %xml-handlers.script.qname;
      %XML-EVENTS.xmlns.attrib;
      xml:id       ID                       #IMPLIED
      charset      %Charset.datatype;       #IMPLIED
      type         %ContentType.datatype;   #REQUIRED
      src          %URI.datatype;           #IMPLIED
      defer        ( defer )                #IMPLIED
>
<!-- end of xml-handlers.script.attlist -->]]>

<!ENTITY % xml-handlers.dispatchEvent.content "NONE" >
<!ELEMENT %xml-handlers.dispatchEvent.qname; 
          %xml-handlers.dispatchEvent.content >

<ENTITY % xml-handlers.dispatchEvent.attlist "INCLUDE" >
<![%xml-handlers.dispatchEvent.attlist;[
<!ATTLIST %xml-handlers.dispatchEvent.qname;
      %XML-EVENTS.xmlns.attrib;
      xml:id       ID                       #IMPLIED
      destid       IDREF                    #IMPLIED
      raise        %QName.datatype;         #IMPLIED
      bubbles      ( bubbles )              #IMPLIED
      cancelable   ( cancelable )           #IMPLIED
>
<!-- end of xml-handlers.dispatchEvent.attlist -->]]>

<!ENTITY % xml-handlers.addEventListener.content "NONE" >
<!ELEMENT %xml-handlers.addEventListener.qname; 
          %xml-handlers.addEventListener.content >

<ENTITY % xml-handlers.addEventListener.attlist "INCLUDE" >
<![%xml-handlers.addEventListener.attlist;[
<!ATTLIST %xml-handlers.addEventListener.qname;
      %XML-EVENTS.xmlns.attrib;
      xml:id       ID                       #IMPLIED
      event        %QName.datatype;         #REQUIRED
      handler      IDREF                    #REQUIRED
      phase        (capture|default)        #IMPLIED
>
<!-- end of xml-handlers.addEventListener.attlist -->]]>

<!ENTITY % xml-handlers.removeEventListener.content "NONE" >
<!ELEMENT %xml-handlers.removeEventListener.qname; 
          %xml-handlers.removeEventListener.content >

<ENTITY % xml-handlers.removeEventListener.attlist "INCLUDE" >
<![%xml-handlers.removeEventListener.attlist;[
<!ATTLIST %xml-handlers.removeEventListener.qname;
      %XML-EVENTS.xmlns.attrib;
      xml:id       ID                       #IMPLIED
      event        %QName.datatype;         #REQUIRED
      handler      IDREF                    #REQUIRED
      phase        (capture|default)        #IMPLIED
>
<!-- end of xml-handlers.addEventListener.attlist -->]]>

<!ENTITY % xml-handlers.stopPropagation.content "NONE" >
<!ELEMENT %xml-handlers.stopPropagation.qname; 
          %xml-handlers.stopPropagation.content >

<ENTITY % xml-handlers.stopPropagation.attlist "INCLUDE" >
<![%xml-handlers.stopPropagation.attlist;[
<!ATTLIST %xml-handlers.stopPropagation.qname;
      %XML-EVENTS.xmlns.attrib;
      xml:id       ID                       #IMPLIED
      event        %QName.datatype;         #REQUIRED
>
<!-- end of xml-handlers.stopPropagation.attlist -->]]>

<!ENTITY % xml-handlers.preventDefault.content "NONE" >
<!ELEMENT %xml-handlers.preventDefault.qname; 
          %xml-handlers.preventDefault.content >

<ENTITY % xml-handlers.preventDefault.attlist "INCLUDE" >
<![%xml-handlers.preventDefault.attlist;[
<!ATTLIST %xml-handlers.preventDefault.qname;
      %XML-EVENTS.xmlns.attrib;
      xml:id       ID                       #IMPLIED
      event        %QName.datatype;         #REQUIRED
>
<!-- end of xml-handlers.preventDefault.attlist -->]]>

<!-- end of xml-handlers-2.mod -->

B.Schema Implementation

This appendix is normative.

The schema implementation of XML Events conforms to the requirements defined in [XHTMLSCHEMAMOD]. It is divided into an attributes module and an element module for the XML Events module defined in this Proposed Recommendation.

B.1.Attributes Module

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema 
    targetNamespace="http://www.w3.org/2001/xml-events" 
    xmlns:ev="http://www.w3.org/2001/xml-events" 
    xmlns:xs="http://www.w3.org/2001/XMLSchema" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://www.w3.org/2001/XMLSchema 
                        http://www.w3.org/2001/XMLSchema.xsd" 
    elementFormDefault="unqualified" 
    blockDefault="#all" 
    finalDefault="#all" 
    attributeFormDefault="unqualified">

  <xs:annotation>
    <xs:documentation>
      This is the XML Schema for XML Events global attributes

      URI: http://www.w3.org/MarkUp/SCHEMA/xml-events-attribs-2.xsd
      $Id: Overview.html,v 1.2 2017/10/02 10:35:09 denis Exp $
    </xs:documentation>
    <xs:documentation source="xml-events-copyright-2.xsd"/>
  </xs:annotation>

  <xs:annotation>
    <xs:documentation>
      XML Event Attributes
        
        These "global" event attributes are defined in "Attaching
        Attributes Directly to the Observer Element" of the XML
        Events specification.
    </xs:documentation>
  </xs:annotation>

  <xs:attribute name="event" type="xs:NMTOKEN"/>
  <xs:attribute name="observer" type="xs:IDREF"/>
  <xs:attribute name="target" type="xs:IDREF"/>
  <xs:attribute name="handler" type="xs:anyURI"/>
  <xs:attribute name="condition" type="xs:normalizedString"/>
  <xs:attribute name="phase" default="default">
    <xs:simpleType>
      <xs:restriction base="xs:NMTOKEN">
        <xs:enumeration value="capture"/>
        <xs:enumeration value="default"/>
      </xs:restriction>
    </xs:simpleType>
  </xs:attribute>
  <xs:attribute name="propagate" default="continue">
    <xs:simpleType>
      <xs:restriction base="xs:NMTOKEN">
        <xs:enumeration value="stop"/>
        <xs:enumeration value="continue"/>
      </xs:restriction>
    </xs:simpleType>
  </xs:attribute>
  <xs:attribute name="defaultAction" default="perform">
    <xs:simpleType>
      <xs:restriction base="xs:NMTOKEN">
        <xs:enumeration value="cancel"/>
        <xs:enumeration value="perform"/>
      </xs:restriction>
    </xs:simpleType>
  </xs:attribute>

  <xs:attributeGroup name="XmlEvents.attlist">
    <xs:attribute ref="ev:event"/>
    <xs:attribute ref="ev:observer"/>
    <xs:attribute ref="ev:target"/>
    <xs:attribute ref="ev:handler"/>
    <xs:attribute ref="ev:condition"/>
    <xs:attribute ref="ev:phase"/>
    <xs:attribute ref="ev:propagate"/>
    <xs:attribute ref="ev:defaultAction"/>
  </xs:attributeGroup>

</xs:schema>

B.2.XML Events Module

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema 
    targetNamespace="http://www.w3.org/2001/xml-events" 
    xmlns="http://www.w3.org/2001/xml-events" 
    xmlns:xs="http://www.w3.org/2001/XMLSchema" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://www.w3.org/2001/XMLSchema 
                        http://www.w3.org/2001/XMLSchema.xsd" 
    elementFormDefault="unqualified" 
    blockDefault="#all" 
    finalDefault="#all" 
    attributeFormDefault="unqualified">

  <xs:annotation>
    <xs:documentation>
      This is the XML Schema for XML Events

      URI: http://www.w3.org/MarkUp/SCHEMA/xml-events-2.xsd
      $Id: Overview.html,v 1.2 2017/10/02 10:35:09 denis Exp $
    </xs:documentation>
    <xs:documentation source="xml-events-copyright-2.xsd"/>
  </xs:annotation>

  <xs:annotation>
    <xs:documentation>
      XML Events element listener
        
        This module defines the listener element for XML Events.
        This element can be used to define event listeners. This
        module relies upon the XmlEvents.attlist attribute group
        defined in xml-events-attribs-2.xsd.
    </xs:documentation>
  </xs:annotation>

  <xs:attributeGroup name="listener.attlist">
    <xs:attribute name="event" use="required" type="xs:NMTOKEN"/>
    <xs:attribute name="observer" type="xs:IDREF"/>
    <xs:attribute name="target" type="xs:IDREF"/>
    <xs:attribute name="handler" type="xs:anyURI"/>
    <xs:attribute name="condition" type="xs:normalizedString"/>
    <xs:attribute name="phase" default="default">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="capture"/>
          <xs:enumeration value="default"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>
    <xs:attribute name="propagate" default="continue">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="stop"/>
          <xs:enumeration value="continue"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>
    <xs:attribute name="defaultAction" default="perform">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="cancel"/>
          <xs:enumeration value="perform"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>
    <xs:attribute name="id" type="xs:ID"/>
  </xs:attributeGroup>

  <xs:complexType name="listener.type">
    <xs:attributeGroup ref="listener.attlist"/>
  </xs:complexType>

  <xs:element name="listener" type="listener.type"/>

</xs:schema>

B.3.XML Handlers Module

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema 
    targetNamespace="http://www.w3.org/2001/xml-events" 
    xmlns="http://www.w3.org/2001/xml-events" 
    xmlns:xs="http://www.w3.org/2001/XMLSchema" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://www.w3.org/2001/XMLSchema 
                        http://www.w3.org/2001/XMLSchema.xsd" 
    elementFormDefault="unqualified" 
    blockDefault="#all" 
    finalDefault="#all" 
    attributeFormDefault="unqualified">

  <xs:annotation>
    <xs:documentation>
      This is the XML Schema for XML Events

      URI: http://www.w3.org/MarkUp/SCHEMA/xml-handlers-2.xsd
      $Id: Overview.html,v 1.2 2017/10/02 10:35:09 denis Exp $
    </xs:documentation>
    <xs:documentation source="xml-events-copyright-2.xsd"/>
  </xs:annotation>

  <xs:attributeGroup name="action.attlist">
    <xs:attribute name="event" use="required" type="xs:NMTOKEN"/>
    <xs:attribute name="observer" type="xs:IDREF"/>
    <xs:attribute name="target" type="xs:IDREF"/>
    <xs:attribute name="handler" type="xs:anyURI"/>
    <xs:attribute name="condition" type="xs:normalizedString"/>
    <xs:attribute name="phase" default="default">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="capture"/>
          <xs:enumeration value="default"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>
    <xs:attribute name="propagate" default="continue">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="stop"/>
          <xs:enumeration value="continue"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>
    <xs:attribute name="defaultAction" default="perform">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="cancel"/>
          <xs:enumeration value="perform"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>
    <xs:attribute name="id" type="xs:ID"/>
  </xs:attributeGroup>

  <xs:complexType name="action.type">
    <xs:attributeGroup ref="action.attlist"/>
  </xs:complexType>

  <xs:element name="action" type="action.type"/>

  <xs:complexType name="script.type">
    <xs:attributeGroup ref="script.attlist"/>
  </xs:complexType>

  <xs:element name="script" type="script.type"/>

  <xs:complexType name="dispatchEvent.type">
    <xs:attributeGroup ref="dispatchEvent.attlist"/>
  </xs:complexType>

  <xs:element name="dispatchEvent" type="dispatchEvent.type"/>

  <xs:complexType name="addEventListener.type">
    <xs:attributeGroup ref="addEventListener.attlist"/>
  </xs:complexType>

  <xs:element name="addEventListener" type="addEventListener.type"/>

  <xs:complexType name="removeEventListener.type">
    <xs:attributeGroup ref="removeEventListener.attlist"/>
  </xs:complexType>

  <xs:element name="removeEventListener" type="removeEventListener.type"/>

  <xs:complexType name="stopPropagation.type">
    <xs:attributeGroup ref="stopPropagation.attlist"/>
  </xs:complexType>

  <xs:element name="stopPropagation" type="stopPropagation.type"/>

  <xs:complexType name="preventDefault.type">
    <xs:attributeGroup ref="preventDefault.attlist"/>
  </xs:complexType>

  <xs:element name="preventDefault" type="stopPropagation.type"/>
</xs:schema>

C.Implementation Notes

This appendix is informative.

XML Events is intended as a declarative way to use DOM Events, but it is not necessarily limited to that. For example, it would be possible to use XML Events in a tree-based system that does not support a DOM. The mapping to DOM 3 Events is straightforward, and XML Events 2 provides mark-up that reflects all features of DOM 3 Events. The mapping to DOM 2 Events is slightly more involved, and requires some processing of event names, since in XML Events 2 event names are QNames. DOM 2 Events allows a string for the event name, and a suggested practice is to convert the QName to a URI by concatenating the local part to the namespace, and then use the URI as the event name.

D.References

This appendix is normative.

D.1.Normative References

[DOM2EVENTS]
"Document Object Model (DOM) Level 2 Events Specification", W3C Recommendation, T. Pixley, ed., 13 November 2000.
Available at: http://www.w3.org/TR/DOM-Level-2-Events/
The latest version is available at: http://www.w3.org/TR/DOM-Level-2-Events
[XML]
"Extensible Markup Language (XML) 1.0 (Second Edition)", W3C Recommendation, T. Bray et al., eds., 6 October 2000.
Available at: http://www.w3.org/TR/2000/REC-xml-20001006
The latest version is available at: http://www.w3.org/TR/REC-xml
[SCHEMA]
"XML Schema Part 2: Datatypes", W3C Recommendation, P. V. Biron et al., eds., 2 May 2001.
Available at: http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/
The latest version is available at: http://www.w3.org/TR/xmlschema-2/
[RFC2119]
"Key words for use in RFCs to indicate requirement levels", RFC 2119, S. Bradner, March 1997.
Available at: http://www.rfc-editor.org/rfc/rfc2119.txt
[XMLID]
"xml:id Version 1.0", W3C Candidate Recommendation, J. Marsh, D. Veillard, N. Walsh, eds., 8 February 2005, work in progress.
Available at: http://www.w3.org/TR/2005/CR-xml-id-20050208/
[XMLNAMES]
"Namespaces in XML", W3C Recommendation, T. Bray et al., eds., 14 January 1999.
Available at: http://www.w3.org/TR/1999/REC-xml-names-19990114
The latest version is available at: http://www.w3.org/TR/REC-xml-names
[XPATH]
"XML Path Language", W3C Recommendation, James Clark, et al., eds., 16 November 1999.
Available at: http://www.w3.org/TR/1999/REC-xpath-19991116
The latest version is available at: http://www.w3.org/TR/xpath

D.2.Other References

[HTML4]
"HTML 4.01 Specification", W3C Recommendation, D. Raggett et al., eds., 24 December 1999.
Available at: http://www.w3.org/TR/1999/REC-html401-19991224
The latest version is available at: http://www.w3.org/TR/html4
[SMIL20]
"Synchronized Multimedia Integration Language (SMIL 2.0)", W3C Recommendation, J. Ayars et al., eds., 7 August 2001.
Available at: http://www.w3.org/TR/2001/REC-smil20-20010807/
The latest version is available at: http://www.w3.org/TR/smil20
[SVG]
"Scalable Vector Graphics (SVG) 1.0 Specification", W3C Recommendation, J. Ferraiolo, ed., 4 September 2001.
Available at: http://www.w3.org/TR/2001/REC-SVG-20010904/
The latest version is available at: http://www.w3.org/TR/SVG/
[XFORMS]
"XForms 1.1", W3C Working Draft, M. Dubinko et al., eds., 15 November 2004.
Available at: http://www.w3.org/TR/2004/WD-xforms11-20041115/
[XHTML]
"XHTML™ 1.0: The Extensible HyperText Markup Language (Second Edition)". S. Pemberton et al., 26 January 2000, revised 1 August 2002.
Available at: http://www.w3.org/TR/2002/REC-xhtml1-20020801
The latest version is available at: http://www.w3.org/TR/xhtml1
[XHTMLMOD]
"Modularization of XHTML™ 1.1", W3C Proposed Recommendation, D. Austin et al., eds., 13 February 2006.
Available at: http://www.w3.org/TR/2006/PR-xhtml-modularization-20060213
The latest version is available at: http://www.w3.org/TR/xhtml-modularization
[XHTMLSCHEMAMOD]
"Modularization of XHTML™ in XML Schema", W3C Working Draft, D. Austin et al., eds., 3 October 2003, work in progress.
Available at: http://www.w3.org/TR/2003/WD-xhtml-m12n-schema-20031003
The latest version is available at: http://www.w3.org/TR/xhtml-m12n-schema

E.Acknowledgments

This section is informative.

This document was originally edited by Ted Wugofski (Openwave).

Special acknowledgments to: Mark Baker (Sun Microsystems), Wayne Carr (Intel Corporation), Warner ten Kate (Philips Electronics), Patrick Schmitz, and Peter Stark (Ericsson) for their significant contributions to the evolution of this specification.

At the time of publication, the participants in the W3C HTML Working Group were: