svn commit: r574010 - /wicket/trunk/jdk-1.4/wicket/src/main/java/org/apache/wicket/ajax/markup/html/form/AjaxSubmitLink.java

[gw...@apache.org]

Author: gwynevans
Date: Sun Sep  9 06:11:08 2007
New Revision: 574010

URL: http://svn.apache.org/viewvc?rev=574010&view=rev
Log:
Added Martijn's AjaxFallback background/explanation to the JavaDoc

Modified:
    wicket/trunk/jdk-1.4/wicket/src/main/java/org/apache/wicket/ajax/markup/html/form/AjaxSubmitLink.java

Modified: wicket/trunk/jdk-1.4/wicket/src/main/java/org/apache/wicket/ajax/markup/html/form/AjaxSubmitLink.java
URL: http://svn.apache.org/viewvc/wicket/trunk/jdk-1.4/wicket/src/main/java/org/apache/wicket/ajax/markup/html/form/AjaxSubmitLink.java?rev=574010&r1=574009&r2=574010&view=diff
==============================================================================
--- wicket/trunk/jdk-1.4/wicket/src/main/java/org/apache/wicket/ajax/markup/html/form/AjaxSubmitLink.java (original)
+++ wicket/trunk/jdk-1.4/wicket/src/main/java/org/apache/wicket/ajax/markup/html/form/AjaxSubmitLink.java Sun Sep  9 06:11:08 2007
@@ -29,6 +29,35 @@
  * constructor argument it does not need to be inside form's component
  * hierarchy.
  * 
+ * <p/>
+ * It works by splitting the javascript/Ajax calls from the normal
+ * non-ajax requests by generating:
+ * <pre>
+ * &lt;a href="normal action url" onclick="ajax javascript script; return
+ * false;"&gt;link&lt;/a&gt;
+ * </pre>
+ * If/when javascript is turned off in the browser, or it doesn't support
+ * javascript, then the browser will not respond to the onclick event,
+ * using the href directly. Wicket will then use a normal request target,
+ * and call the serverside onClick with a null {@link AjaxRequestTarget}.
+ *
+ * If javascript is enabled, Wicket will send an ajax request, and
+ * process it serverside with an {@link AjaxRequestTarget} that is supplied to
+ * the server-side onClick method. The "return false" in the &lt;a href&gt;
+ * onclick handler ensures the browser doesn't perform the normal request
+ * too.
+ *
+ * The latter is nicely illustrated with this:
+ * <pre>
+ * &lt;a href="javascript:alert('href event handler');"
+ * onclick="alert('onclick event handler');"&gt;clicking me gives two
+ * alerts&lt;/a&gt;
+ *
+ * &lt;a href="javascript:alert('href event handler');"
+ * onclick="alert('onclick event handler');return false;"&gt;clicking me
+ * gives only one alert&lt;/a&gt;
+ * </pre>
+ *
  * @since 1.2
  * 
  * @author Igor Vaynberg (ivaynberg)