- From: Ian Hickson via cvs-syncmail <cvsmail@w3.org>
- Date: Fri, 07 Oct 2011 22:31:42 +0000
- To: public-html-commits@w3.org
Update of /sources/public/html5/spec
In directory hutz:/tmp/cvs-serv16191
Modified Files:
Overview.html
Log Message:
Tidy up how event handlers are defined to line up better with WebIDL and DOM Core (whatwg r6654)
Index: Overview.html
===================================================================
RCS file: /sources/public/html5/spec/Overview.html,v
retrieving revision 1.5335
retrieving revision 1.5336
diff -u -d -r1.5335 -r1.5336
--- Overview.html 7 Oct 2011 22:01:40 -0000 1.5335
+++ Overview.html 7 Oct 2011 22:31:39 -0000 1.5336
@@ -50510,13 +50510,14 @@
list of <a href="#concept-event-listener" title="concept-event-listener">event listeners</a>
associated with <var title="">T</var> with <i>type</i> set to the
<dfn id="event-handler-event-type">event handler event type</dfn> corresponding to <var title="">H</var>, <i>capture</i> set to false, and <i>listener</i>
- set to be an anonymous function that does nothing when the event
- handler's value is not a <code><a href="#function">Function</a></code> object and <a href="#concept-function-invoke" title="concept-Function-invoke">invokes the <code>Function</code>
- object</a> associated with the <a href="#event-handlers" title="event handlers">event
- handler</a> otherwise. <a href="#refsDOMCORE">[DOMCORE]</a></p>
+ set to <a href="#the-event-handler-processing-algorithm">the event handler processing algorithm</a> defined
+ below. <a href="#refsDOMCORE">[DOMCORE]</a></p>
<p class="note">The <i>listener</i> is emphatically <em>not</em> the
- <a href="#event-handlers" title="event handlers">event handler</a> itself.</p>
+ <a href="#event-handlers" title="event handlers">event handler</a> itself. Every
+ event handler ends up registering the same <i>listener</i>, the
+ algorithm defined below, which takes care of invoking the right
+ callback, and processing the callback's return value.</p>
<p class="note">This only happens the first time the <a href="#event-handlers" title="event handlers">event handler</a>'s value is set. Since
listeners are called in the order they were registered, the order of
@@ -50552,41 +50553,57 @@
not influence whether an <a href="#event-handlers" title="event handlers">event
handler</a> is triggered or not.</p>
- <p>When an <a href="#event-handlers" title="event handlers">event handler</a>'s
- <code><a href="#function">Function</a></code> object is <dfn id="concept-function-invoke" title="concept-Function-invoke">invoked</dfn>, its <code title="dom-function-call"><a href="#dom-function-call">call()</a></code> callback must be invoked
- with one argument, set to the <code><a href="#event">Event</a></code> object of the event
- in question.</p>
+ <p>The <dfn id="the-event-handler-processing-algorithm">the event handler processing algorithm</dfn> for an
+ <a href="#event-handlers" title="event handlers">event handler</a> <var title="">H</var> and an <code><a href="#event">Event</a></code> object <var title="">E</var> is as follows:</p>
- <p>The handler's return value must then be processed as follows:</p>
+ <ol><li><p>If <var title="">H</var>'s value is null, then abort these
+ steps.</li>
- <dl class="switch"><dt>If the event type is <code class="event-mouseover">mouseover</code></dt>
+ <li><p>Let <var title="">callback</var> be <var title="">H</var>'s
+ value, the <code><a href="#function">Function</a></code> object that the <a href="#event-handlers" title="event
+ handlers">event handler</a> was last set to.</li>
- <dd><p>If the return value is a boolean with the value true, then
- the event must be canceled.</dd>
+ <li><p>Invoke <var title="">callback</var>'s <code title="dom-function-call"><a href="#dom-function-call">call()</a></code> operation with one
+ argument, the value of which is the <code><a href="#event">Event</a></code> object <var title="">E</var>, with the <i title="dfn-callback-this-value">callback this value</i> set to the
+ <var title="">E</var>'s <code title="dom-Event-currentTarget">currentTarget</code>. Let the
+ return value be <var title="">return value</var>. <a href="#refsWEBIDL">[WEBIDL]</a></p>
- <dt>If the event object is a <code><a href="#beforeunloadevent">BeforeUnloadEvent</a></code> object</dt>
+ <li>
- <dd><p>If the return value is a string, and the event object's
- <code title="dom-BeforeUnloadEvent-returnValue"><a href="#dom-beforeunloadevent-returnvalue">returnValue</a></code>
- attribute's value is the empty string, then set the <code title="dom-BeforeUnloadEvent-returnValue"><a href="#dom-beforeunloadevent-returnvalue">returnValue</a></code>
- attribute's value to the return value.</dd>
+ <li>
- <dt>Otherwise</dt>
+ <p>Process <var title="">return value</var> as follows:</p>
- <dd><p>If the return value is a boolean with the value false, then
- the event must be canceled.</dd>
+ <dl class="switch"><dt>If the event type is <code class="event-mouseover">mouseover</code></dt>
- </dl></div><hr><p>The <code><a href="#function">Function</a></code> interface represents a function in the
- scripting language being used. It is represented in IDL as
+ <dd><p>If <var title="">return value</var> is a boolean with the
+ value true, then cancel the event.</dd>
+
+ <dt>If the <code><a href="#event">Event</a></code> object <var title="">E</var> is a
+ <code><a href="#beforeunloadevent">BeforeUnloadEvent</a></code> object</dt>
+
+ <dd><p>If <var title="">return value</var> is a string, and the
+ <code><a href="#event">Event</a></code> object <var title="">E</var>'s <code title="dom-BeforeUnloadEvent-returnValue"><a href="#dom-beforeunloadevent-returnvalue">returnValue</a></code>
+ attribute's value is the empty string, then set the <code title="dom-BeforeUnloadEvent-returnValue"><a href="#dom-beforeunloadevent-returnvalue">returnValue</a></code>
+ attribute's value to <var title="">return value</var>.</dd>
+
+ <dt>Otherwise</dt>
+
+ <dd><p>If <var title="">return value</var> is a boolean with the
+ value false, then cancel the event.</dd>
+
+
+
+ </dl></li>
+
+ </ol></div><hr><p>The <code><a href="#function">Function</a></code> interface represents a function in the
+ scripting language being used. It is represented in Web IDL as
follows:<pre class="idl">[Callback=FunctionOnly, NoInterfaceObject]
interface <dfn id="function">Function</dfn> {
any <a href="#dom-function-call" title="dom-function-call">call</a>(any... arguments);
};</pre><p>The <dfn id="dom-function-call" title="dom-function-call"><code>call(...)</code></dfn>
method is the object's callback.<p class="note">In JavaScript, any <code title="">Function</code>
- object implements this interface.<p>If the <code><a href="#function">Function</a></code> object is a JavaScript <code title="">Function</code>, then when it is invoked by the user agent,
- the user agent must set the <var title="">thisArg</var> (as defined
- by ECMAScript edition 5 section 10.4.3 Entering Function Code) to
- the <a href="#event-handlers" title="event handlers">event handler</a>'s object. <a href="#refsECMA262">[ECMA262]</a><div class="example">
+ object implements this interface.<div class="example">
<p>For example, the following document fragment:</p>
@@ -50596,11 +50613,13 @@
and an alert saying "<code title="">[object HTMLBodyElement]</code>" whenever the user
clicks something in the page.</p>
- </div><p>The return value of the function affects whether the event is
- canceled or not: <span class="impl">as described above,</span> if
- the return value is false, the event is canceled (except for <code class="event-mouseover">mouseover</code> events, where the return
- value has to be true to cancel the event). With <code title="event-beforeunload">beforeunload</code> events, the value is
- instead used to determine the message to show the user.<h5 id="event-handlers-on-elements-document-objects-and-window-objects"><span class="secno">6.1.6.2 </span>Event handlers on elements, <code><a href="#document">Document</a></code> objects, and <code><a href="#window">Window</a></code> objects</h5><p>The following are the <a href="#event-handlers">event handlers</a> (and their
+ </div><p class="note">The return value of the function affects whether the
+ event is canceled or not: <span class="impl">as described
+ above,</span> if the return value is false, the event is canceled
+ (except for <code class="event-mouseover">mouseover</code> events,
+ where the return value has to be true to cancel the event). With
+ <code title="event-beforeunload">beforeunload</code> events, the
+ value is instead used to determine the message to show the user.<h5 id="event-handlers-on-elements-document-objects-and-window-objects"><span class="secno">6.1.6.2 </span>Event handlers on elements, <code><a href="#document">Document</a></code> objects, and <code><a href="#window">Window</a></code> objects</h5><p>The following are the <a href="#event-handlers">event handlers</a> (and their
corresponding <a href="#event-handler-event-type" title="event handler event type">event handler
event types</a>) <span class="impl">that must be</span> supported
by all <a href="#html-elements">HTML elements</a>, as both content attributes and
Received on Friday, 7 October 2011 22:31:49 UTC