Added a standards divergence warning to on.xml

Returning false in jQuery event handlers stops the propagation of the event, while returning false in native event listeners only prevents the default.

Author: phistuck

entries/on.xml

@@ -67,6 +67,7 @@ $( "button" ).on( "click", notify );
     <p>By default, most events bubble up from the original event target to the <code>document</code> element. At each element along the way, jQuery calls any matching event handlers that have been attached. A handler can prevent the event from bubbling further up the document tree (and thus prevent handlers on those elements from running) by calling <code>event.stopPropagation()</code>. Any other handlers attached on the current element <em>will</em> run however. To prevent that, call <code>event.stopImmediatePropagation()</code>. (Event handlers bound to an element are called in the same order that they were bound.)</p>
     <p>Similarly, a handler can call <code>event.preventDefault()</code> to cancel any default action that the browser may have for this event; for example, the default action on a <code>click</code> event is to follow the link. Not all browser events have default actions, and not all default actions can be canceled. See the <a href="http://www.w3.org/TR/DOM-Level-3-Events/#event-types-list">W3C Events Specification</a> for details.</p>
     <p>Returning <code>false</code> from an event handler will automatically call <code>event.stopPropagation()</code> and <code>event.preventDefault()</code>. A <code>false</code> value can also be passed for the <code>handler</code> as a shorthand for <code>function(){ return false; }</code>. So, <code>$( "a.disabled" ).on( "click", false );</code> attaches an event handler to all links with class "disabled" that prevents them from being followed when they are clicked and also stops the event from bubbling. </p>
+    <div class="warning"><strong>Note:</strong> the consequences of returning <code>false</code> from an event handler in jQuery differ from returning <code>false</code> from a native event handler (<code>element.addEventListener("click", function () { return false; })</code>) in that jQuery calls <code>event.preventDefault()</code> and <code>event.stopPropagation()</code> and a native event handler only calls <code>event.preventDefault()</code>.</div>
     <p>When jQuery calls a handler, the <code>this</code> keyword is a reference to the element where the event is being delivered; for directly bound events this is the element where the event was attached and for delegated events this is an element matching <code>selector</code>. (Note that <code>this</code> may not be equal to <code>event.target</code> if the event has bubbled from a descendant element.) To create a jQuery object from the element so that it can be used with jQuery methods, use <code>$( this )</code>.</p>
     <h2 id="passing-data">Passing data to the handler</h2>
     <p>If a <code>data</code> argument is provided to <code>.on()</code> and is not <code>null</code> or <code>undefined</code>, it is passed to the handler in the <a href="/event.data/"><code>event.data</code></a> property each time an event is triggered. The <code>data</code> argument can be any type, but if a string is used the <code>selector</code> must either be provided or explicitly passed as <code>null</code> so that the data is not mistaken for a selector. Best practice is to use a plain object so that multiple values can be passed as properties.</p>