Modified: wicket/common/site/trunk/_site/guide/guide/pages/chapter7_2.html URL: http://svn.apache.org/viewvc/wicket/common/site/trunk/_site/guide/guide/pages/chapter7_2.html?rev=1548920&r1=1548919&r2=1548920&view=diff ============================================================================== --- wicket/common/site/trunk/_site/guide/guide/pages/chapter7_2.html (original) +++ wicket/common/site/trunk/_site/guide/guide/pages/chapter7_2.html Sat Dec 7 14:58:57 2013 @@ -175,7 +175,7 @@ function addJsClass() { }</pre></div><p class="paragraph"/>Now if we run the new example (project LifeCycleStagesRevisited) and we click on the âReloadâ button, a new page version is created and the page id is increased by one:<p class="paragraph"/><img border="0" class="center" src="../img/reload-page.png"></img><p class="paragraph"/>If we press the back button the page version previously rendered (and serialized) will be retrieved (i.e. deserialized) and it will be used again to respond to our request (and page id is decremented):<p class="paragraph"/><img border="0" class="center" src="../img/browser-back.png"></img><p class="paragraph"/><blockquote class="note"> For more details about page storing you can visit the wiki page at https://cwiki.apache.org/confluence/display/WICKET/Page+Storage . On this page you can find which classes are involved into page storing mechanism and how they work together. -</blockquote><p class="paragraph"/>As we have stated at the beginning of this chapter, page versions are stored using Java serialization, therefore every object referenced inside a page must be serializable1. In paragraph 9.6 we will see how to overcome this limit and work with non-serializable objects in our components using detachable Wicket models.<p class="paragraph"/><h3>Using a specific page version with PageReference</h3><p class="paragraph"/>To retrieve a specific page version in our code we can use class org.apache.wicket. PageReference by providing its constructor with the corresponding page id:<p class="paragraph"/><div class="code"><pre>//load page version with page id = 3 +</blockquote><p class="paragraph"/>As we have stated at the beginning of this chapter, page versions are stored using Java serialization, therefore every object referenced inside a page must be serializable1. In paragraph 9.6 we will see how to overcome this limit and work with non-serializable objects in our components using detachable Wicket models.<p class="paragraph"/><h3>Using a specific page version with PageReference</h3><p class="paragraph"/>To retrieve a specific page version in our code we can use class org.apache.wicket.PageReference by providing its constructor with the corresponding page id:<p class="paragraph"/><div class="code"><pre>//load page version with page id = 3 PageReference pageReference = <span class="java-keyword">new</span> PageReference(3); //load the related page instance Page page = pageReference.getPage();</pre></div><p class="paragraph"/>To get the related page instance we must use method getPage.<p class="paragraph"/><h3>Turning off page versioning</h3><p class="paragraph"/>If for any reason we need to switch off versioning for a given page, we can call its method setVersioned(false).<p class="paragraph"/><h3>Pluggable serialization</h3><p class="paragraph"/>Starting from version 1.5 it is possible to choose which implementation of Java serialization will be used by Wicket to store page versions. Wicket serializes pages using an implementation of interface org.apache.wicket.serialize.ISerializer. The default implementation is org.apache.wicket.serialize.java.JavaSerializer and it uses the standard Java serialization mechanism based on classes ObjectOutputStream and ObjectInputStream. However on Internet we can find other interesting serialization libraries like Kryo1 which performs faster then the standard implementation.The serializer in use can be customized with the setSerializer(ISerializer) method defined by setting interface org.apache.wicket.settings.IFrameworkSettings.<p class="paragraph"/>We can access this interface inside the method init of the class Application using the getFrameworkSettings() method :<p class="paragraph"/><div class="code"><pre>@Override @@ -183,7 +183,7 @@ Page page = pageReference.getPage();</pr { <span class="java-keyword">super</span>.init(); getFrameworkSettings().setSerializer(yourSerializer); -}</pre></div><p class="paragraph"/>A serializer based on Kryo library is provided by the WicketStuff project. You can find more information on this project, as well as the instructions to use its modules, in Appendix B.<p class="paragraph"/><h3>Page caching</h3><p class="paragraph"/>By default Wicket persists versions of pages into a session-relative file on disk, but it uses a two-levels cache to speed up this process. The first level of the cache uses a http session attribute called âwicket:persistentPageManagerData-<APPLICATION_NAME>â to store pages. The second level cache stores pages into application-scoped variables which are identified by a session id and a page id.<p class="paragraph"/>The following picture is an overview of these two caching levels:<p class="paragraph"/><img border="0" class="center" src="../img/wicket-cache.png"></img><p class="paragraph"/>The session-scoped cache is faster then the other memory levels but it contains only the pages used to serve the last request. Wicket allows us to set the maximum amount of memory allowed for the application-scoped cache and for the page store file. Both parameters can be configured via setting interface org.apache .wicket.settings.IStoreSettings.<p class="paragraph"/>This interface provides the setMaxSizePerSession(Bytes bytes) method to set the size for page store file. The Bytes parameter is the maximum size allowed for this file:<p class="paragraph"/><div class="code"><pre>@Override +}</pre></div><p class="paragraph"/>A serializer based on Kryo library is provided by the WicketStuff project. You can find more information on this project, as well as the instructions to use its modules, in Appendix B.<p class="paragraph"/><h3>Page caching</h3><p class="paragraph"/>By default Wicket persists versions of pages into a session-relative file on disk, but it uses a two-levels cache to speed up this process. The first level of the cache uses a http session attribute called âwicket:persistentPageManagerData-<APPLICATION_NAME>â to store pages. The second level cache stores pages into application-scoped variables which are identified by a session id and a page id.<p class="paragraph"/>The following picture is an overview of these two caching levels:<p class="paragraph"/><img border="0" class="center" src="../img/wicket-cache.png"></img><p class="paragraph"/>The session-scoped cache is faster then the other memory levels but it contains only the pages used to serve the last request. Wicket allows us to set the maximum amount of memory allowed for the application-scoped cache and for the page store file. Both parameters can be configured via setting interface org.apache.wicket.settings.IStoreSettings.<p class="paragraph"/>This interface provides the setMaxSizePerSession(Bytes bytes) method to set the size for page store file. The Bytes parameter is the maximum size allowed for this file:<p class="paragraph"/><div class="code"><pre>@Override <span class="java-keyword">public</span> void init() { <span class="java-keyword">super</span>.init();
Modified: wicket/common/site/trunk/_site/guide/guide/pages/chapter8_3.html URL: http://svn.apache.org/viewvc/wicket/common/site/trunk/_site/guide/guide/pages/chapter8_3.html?rev=1548920&r1=1548919&r2=1548920&view=diff ============================================================================== --- wicket/common/site/trunk/_site/guide/guide/pages/chapter8_3.html (original) +++ wicket/common/site/trunk/_site/guide/guide/pages/chapter8_3.html Sat Dec 7 14:58:57 2013 @@ -168,7 +168,7 @@ This paragraph will provide just the bas <li>a page class, via the urlFor(Class<C> pageClass, PageParameters parameters) method</li> <li>an IRequestHandler via the urlFor(IRequestHandler handler) method</li> <li>a ResourceReference via the urlFor(ResourceReference reference, PageParameters params) method (resource entities will be introduced in chapter 13).</li> -</ul><p class="paragraph"/>The overloaded urlFor method from above also has a corresponding version that returns an instance of org.apache.wicket.request.Url instead of a CharSequence. This version has the prefix 'map' in its name (i.e. it has mapUrlFor as full name).<p class="paragraph"/><h3>Method setResponsePage</h3><p class="paragraph"/>The RequestCycle class contains the implementation of the setResponsePage method we use to redirect a user to a specific page (see paragraph 2.4). The namesake method of class org.apache.wicket. Component is just a convenience method that internally invokes the actual implementation on current request cycle:<p class="paragraph"/><div class="code"><pre><span class="java-keyword">public</span> <span class="java-keyword">final</span> void setResponsePage(<span class="java-keyword">final</span> Page page) { +</ul><p class="paragraph"/>The overloaded urlFor method from above also has a corresponding version that returns an instance of org.apache.wicket.request.Url instead of a CharSequence. This version has the prefix 'map' in its name (i.e. it has mapUrlFor as full name).<p class="paragraph"/><h3>Method setResponsePage</h3><p class="paragraph"/>The RequestCycle class contains the implementation of the setResponsePage method we use to redirect a user to a specific page (see paragraph 2.4). The namesake method of class org.apache.wicket.Component is just a convenience method that internally invokes the actual implementation on current request cycle:<p class="paragraph"/><div class="code"><pre><span class="java-keyword">public</span> <span class="java-keyword">final</span> void setResponsePage(<span class="java-keyword">final</span> Page page) { getRequestCycle().setResponsePage(page); }</pre></div><p class="paragraph"/><h3>RequestCycle's hook methods and listeners</h3><p class="paragraph"/>The RequestCycle comes with some hook methods which can be overridden to perform custom actions when request handling reaches a specific stage. These methods are: <ul class="star"> @@ -190,7 +190,7 @@ This paragraph will provide just the bas <span class="java-keyword">public</span> void init() {<p class="paragraph"/> <span class="java-keyword">super</span>.init();<p class="paragraph"/> IRequestCycleListener myListener; //listener initialization… getRequestCycleListeners().add(myListener) -}</pre></div><p class="paragraph"/>The getRequestCycleListeners method returns an instance of class org.apache.wicket. request.cycle.RequestCycleListenerCollection. This class is a sort of typed collection for IRequestCycleListener and it also implements the <a href="http://en.wikipedia.org/wiki/Composite_pattern"; target="blank">Composite pattern</a> .<p class="paragraph"/> +}</pre></div><p class="paragraph"/>The getRequestCycleListeners method returns an instance of class org.apache.wicket.request.cycle.RequestCycleListenerCollection. This class is a sort of typed collection for IRequestCycleListener and it also implements the <a href="http://en.wikipedia.org/wiki/Composite_pattern"; target="blank">Composite pattern</a> .<p class="paragraph"/> <div style="clear:both;margin-top:15px;"></div> Modified: wicket/common/site/trunk/_site/guide/guide/pages/chapter8_4.html URL: http://svn.apache.org/viewvc/wicket/common/site/trunk/_site/guide/guide/pages/chapter8_4.html?rev=1548920&r1=1548919&r2=1548920&view=diff ============================================================================== --- wicket/common/site/trunk/_site/guide/guide/pages/chapter8_4.html (original) +++ wicket/common/site/trunk/_site/guide/guide/pages/chapter8_4.html Sat Dec 7 14:58:57 2013 @@ -157,7 +157,7 @@ function addJsClass() { <h2 id="chapter8_4">9.4 Session Class</h2> -<p class="paragraph"/>In Wicket we use class org.apache.wicket.Session to handle session-relative informations such as client informations, session attributes, session-level cache (seen in paragraph 6.2.4), etc...<p class="paragraph"/>In addition, we know from paragraph 6.1 that Wicket creates a user session to store versions of stateful pages. Similarly to what happens with RequestCycle, the new Session's instances are generated by the Application class with the newSession(Request request, Response response) method. This method is not declared as final, hence it can be overridden if we need to use a custom implementation of the Session class.<p class="paragraph"/>By default if our custom application class is a subclass of WebApplication, method newSession will return an instance of class org.apache.wicket.protocol.http.WebSession. As we have mentioned talking about RequestCycle, also class Session provides a static get() method which returns the session associated to the current th read.<p class="paragraph"/><h3>Session and listeners</h3><p class="paragraph"/>Similar to the RequestCycle, class org.apache.wicket.Session also offers support for listener entities. With Session these entities must implement the callback interface org.apache.wicket. ISessionListener which exposes only the onCreated(Session session) method. As you might guess from its name, this method is called when a new session is created. Session listeners must be added to our application using a typed collection, just like we have done before with request cycle listeners:<p class="paragraph"/><div class="code"><pre>@Override +<p class="paragraph"/>In Wicket we use class org.apache.wicket.Session to handle session-relative informations such as client informations, session attributes, session-level cache (seen in paragraph 6.2.4), etc...<p class="paragraph"/>In addition, we know from paragraph 6.1 that Wicket creates a user session to store versions of stateful pages. Similarly to what happens with RequestCycle, the new Session's instances are generated by the Application class with the newSession(Request request, Response response) method. This method is not declared as final, hence it can be overridden if we need to use a custom implementation of the Session class.<p class="paragraph"/>By default if our custom application class is a subclass of WebApplication, method newSession will return an instance of class org.apache.wicket.protocol.http.WebSession. As we have mentioned talking about RequestCycle, also class Session provides a static get() method which returns the session associated to the current th read.<p class="paragraph"/><h3>Session and listeners</h3><p class="paragraph"/>Similar to the RequestCycle, class org.apache.wicket.Session also offers support for listener entities. With Session these entities must implement the callback interface org.apache.wicket.ISessionListener which exposes only the onCreated(Session session) method. As you might guess from its name, this method is called when a new session is created. Session listeners must be added to our application using a typed collection, just like we have done before with request cycle listeners:<p class="paragraph"/><div class="code"><pre>@Override <span class="java-keyword">public</span> void init(){<p class="paragraph"/> <span class="java-keyword">super</span>.init();<p class="paragraph"/> //listener initialization… ISessionListener myListener; //add a custom session listener Modified: wicket/common/site/trunk/_site/guide/guide/pages/chapter9_6.html URL: http://svn.apache.org/viewvc/wicket/common/site/trunk/_site/guide/guide/pages/chapter9_6.html?rev=1548920&r1=1548919&r2=1548920&view=diff ============================================================================== --- wicket/common/site/trunk/_site/guide/guide/pages/chapter9_6.html (original) +++ wicket/common/site/trunk/_site/guide/guide/pages/chapter9_6.html Sat Dec 7 14:58:57 2013 @@ -164,7 +164,7 @@ function addJsClass() { mountPage(<span class="java-quote">"/pageMount"</span>, MountedPage.class); //Other initialization code… }</pre></div><p class="paragraph"/>The path provided to mountPage will be used to generate the URL for any page of the specified class:<p class="paragraph"/><div class="code"><pre>//it will <span class="java-keyword">return</span> <span class="java-quote">"/pageMount"</span> -RequestCycle.get().urlFor(MountedPage.class);</pre></div><p class="paragraph"/>Under the hood the mountPage method mounts an instance of the request mapper org.apache. wicket.request.mapper.MountedMapper configured for the given path:<p class="paragraph"/><div class="code"><pre><span class="java-keyword">public</span> <span class="java-keyword">final</span> <T <span class="java-keyword">extends</span> Page> void mountPage(<span class="java-keyword">final</span> <span class="java-object">String</span> path,<span class="java-keyword">final</span> <span class="java-object">Class</span><T> pageClass) { +RequestCycle.get().urlFor(MountedPage.class);</pre></div><p class="paragraph"/>Under the hood the mountPage method mounts an instance of the request mapper org.apache.wicket.request.mapper.MountedMapper configured for the given path:<p class="paragraph"/><div class="code"><pre><span class="java-keyword">public</span> <span class="java-keyword">final</span> <T <span class="java-keyword">extends</span> Page> void mountPage(<span class="java-keyword">final</span> <span class="java-object">String</span> path,<span class="java-keyword">final</span> <span class="java-object">Class</span><T> pageClass) { mount(<span class="java-keyword">new</span> MountedMapper(path, pageClass)); }</pre></div><p class="paragraph"/>Request mappers and the Application's method mount have been introduced in the previous chapter (paragraph 7.3.1).<p class="paragraph"/><h3>Using parameter placeholders with mounted pages</h3><p class="paragraph"/>The path specified for mounted pages can contain dynamic segments which are populated with the values of the named parameters used to build the page. These segments are declared using special segments called parameter placeholders. Consider the path used in the following example:<p class="paragraph"/><div class="code"><pre>mountPage(<span class="java-quote">"/pageMount/${foo}/otherSegm"</span>, MountedPageWithPlaceholder.class);</pre></div><p class="paragraph"/>The path used above is composed by three segments: the first and the last are fixed while the second will be replaced by the value of the named parameter foo that must be provided when the page MountedPageWithPlaceholder is instantiated:<p class="paragraph"/>Jav a code:<p class="paragraph"/><div class="code"><pre>PageParameters pageParameters = <span class="java-keyword">new</span> PageParameters(); pageParameters.add(<span class="java-quote">"foo"</span>, <span class="java-quote">"foo"</span>);<p class="paragraph"/>setResponsePage(MountedPageWithPlaceholder.class, pageParameters)</pre></div><p class="paragraph"/>Generated URL:<p class="paragraph"/><div class="code"><pre><Application path>/pageMount/foo/otherSegm</pre></div><p class="paragraph"/>On the contrary if we manually insert an URL like '<web app path>/pageMount/bar/otherSegm', we can read value 'bar' retrieving the named parameter foo inside our page.<p class="paragraph"/>Place holders can be declared as optional using the '#' character in place of '$':<p class="paragraph"/><div class="code"><pre>mountPage(<span class="java-quote">"/pageMount/#{foo}/otherSegm"</span>, MountedPageOptionalPlaceholder.class);</pre></div><p class="paragraph"/>If the named parameter for an optional placeholder is missing, the corresponding segment is removed from the final URL:<p class="paragraph"/> Java code:<p class="paragraph"/><div class="code"><pre>PageParameters pageParameters = <span class="java-keyword">new</span> PageParameters();
