Wicket why page expires when opening link in new tab? - ajax

Question

I'm building a wicket bootsrap web application with the following specs (from pom.xml):
wicket version: 6.15.0
wicket-bootstrap-core.version: 0.9.3-SNAPSHOT
I have a base page which is the father of my other pages and adds to mark up a horizontal navigation bar on top, with key component:
BootstrapBookmarkablePageLink extends BookmarkablePageLink
This is part of my BasePage.java
public abstract class BasePage extends GenericWebPage<Void> {
private static final long serialVersionUID = 1L;
String username;
public WicketApplication getApp() {
return WicketApplication.class.cast(getApplication());
}
public BasePage(final PageParameters parameters) {
super(parameters);
// Read session data
cachedUsername = (String)
BasicAuthenticationSession.get().getAttribute("username");
// create navbar
add(newNavbar("navbar"));
}
/**
* #return application properties
*/
public Properties getProperties() {
return WicketApplication.get().getProperties();
}
/**
* creates a new {#link Navbar} instance
*
* #param markupId
* The components markup id.
* #return a new {#link Navbar} instance
*/
protected Navbar newNavbar(String markupId) {
Navbar navbar = new Navbar(markupId) {
private static final long serialVersionUID = 1L;
#Override
protected TransparentWebMarkupContainer newCollapseContainer(String
componentId) {
TransparentWebMarkupContainer container =
super.newCollapseContainer(componentId);
container.add(new CssClassNameAppender("bs-navbar-collapse"));
return container;
}
};
navbar.setPosition(Navbar.Position.TOP);
// navbar.setInverted(true);
NavbarButton<Void> myTab = new NavbarButton<Void>(MyPage.class, new
PageParameters().add("name", "")
.add("status", "All").add("date", ""), Model.of("My page"));
NavbarButton<Void> myOtherTab = new NavbarButton<Void>
(MyOtherPage.class, new PageParameters().add("status", "initial")
.add("date", ""), Model.of("My other page"));
navbar.addComponents(NavbarComponents.transform(
Navbar.ComponentPosition.LEFT,
myTab, myOtherTab));
return navbar;
}
}
Then, MyPage renders a filter form, an html table, ajaxbuttons and some links, Some of my components are ajax components:
public class MyPage extends BasePage {
private static final long serialVersionUID = 5772520351966806522L;
#SuppressWarnings("unused")
private static final Logger LOG = LoggerFactory.getLogger(MyPage.class);
private static final Integer DAYS = 270;
private DashboardFilteringPageForm filteringForm;
private CityInitialForm ncForm;
private String CityName;
private String startDate;
private CitysTablePanel citysTable;
private WebMarkupContainer numberOfNodes;
public MyPage(PageParameters parameters) throws ParseException {
super(parameters);
// get Citys list from repo
final List<City> repoCitys = (List<City>) methodToGetCities();
// select number of nodes
numberOfNodes = new WebMarkupContainer("numberOfNodes") {
private static final long serialVersionUID = 5772520351966806522L;
};
numberOfNodes.setOutputMarkupId(true);
ncForm = new CityInitialForm("ncForm");
// validation
add(new FeedbackPanel("feedbackPanel")).setOutputMarkupId(true);
ncForm.getNumberField().setRequired(true);
ncForm.add(new AjaxButton("ncButton") {
private static final long serialVersionUID = -6846211690328190809L;
#Override
protected void onInitialize() {
super.onInitialize();
add(newAjaxFormSubmitBehavior("change"));
}
#Override
protected void onSubmit(AjaxRequestTarget target, Form<?> form) {
// redirect to other page
}
#Override
protected void updateAjaxAttributes(AjaxRequestAttributes
attributes) {
super.updateAjaxAttributes(attributes);
attributes.getAjaxCallListeners().add(new
DisableComponentListener(citysTable));
}
});
numberOfNodes.add(ncForm);
// filters
CityName = parameters.get("name").toString() == null ? "" :
parameters.get("name").toString();
startDate = parameters.get("date").toString();
filteringForm = new DashboardFilteringPageForm("filteringForm") {
private static final long serialVersionUID = -1702151172272765464L;
};
// initialize form inputs
filteringForm.setCityName(CityName);
try {
filteringForm.setStartDate(new SimpleDateFormat("EE MMM dd HH:mm:ss
z yyyy", Locale.ENGLISH)
.parse(getStartDate().equals("") ?
CortexWebUtil.subtractDays(new Date(), DAYS).toString() : getStartDate()));
} catch (Exception e) {
setResponsePage(SignInPage.class, new PageParameters());
}
filteringForm.add(new AjaxButton("button") {
private static final long serialVersionUID = -6846211690328190809L;
#Override
protected void onInitialize() {
super.onInitialize();
add(newAjaxFormSubmitBehavior("change"));
}
#Override
protected void onSubmit(AjaxRequestTarget target, Form<?> paForm) {
// retrieve Citys
filterCitysAjax(target, "All");
}
#Override
protected void updateAjaxAttributes(AjaxRequestAttributes
attributes) {
super.updateAjaxAttributes(attributes);
attributes.getAjaxCallListeners().add(new
DisableComponentListener(citysTable));
}
});
filteringForm.getCityNameTextField().add(new OnChangeAjaxBehavior() {
private static final long serialVersionUID = 1468056167693038096L;
#Override
protected void onUpdate(AjaxRequestTarget target) {
try {
filterCitysAjax(target, "All");
} catch (Exception e) {
System.out.println(e.getMessage());
}
}
#Override
protected void updateAjaxAttributes(AjaxRequestAttributes
attributes) {
super.updateAjaxAttributes(attributes);
attributes.getAjaxCallListeners().add(new
DisableComponentListener(citysTable));
}
});
// new City link
AjaxLink<Void> newCityLink = newCityLink("newCity", repoCitys);
// Citys table
citysTable = new CitysTablePanel("CitysTable", repoCitys);
citysTable.setOutputMarkupId(true);
// add components
add(filteringForm, newCityLink, numberOfNodes, citysTable);
}
private void filterCitysAjax(AjaxRequestTarget target, String status) {
methodToFilterResults();
// re-render table component
CitysTablePanel cityTableNew = new CitysTablePanel("CitysTable", citys);
cityTableNew.setOutputMarkupId(true);
cityTableNew.setVisibilityAllowed(true);
cityTableNew.setVisible(true);
citysTable.replaceWith(cityTableNew);
target.add(cityTableNew);
citysTable = cityTableNew;
target.appendJavaScript(CortexWebUtil.TABLE_ODD_EVEN_ROWS);
}
private AjaxLink<Void> newCityLink(String string, final List<City> Citys) {
final AjaxLink<Void> newCityLink = new AjaxLink<Void>(string) {
private static final long serialVersionUID = -5420108740617806989L;
#Override
public void onClick(final AjaxRequestTarget target) {
numberOfNodes.add(new AttributeModifier("style",
"display:block"));
target.add(numberOfNodes);
}
};
// new City image
Image newCityImage = new Image("newCityIcon", new
ContextRelativeResource("/img/new_City_icon.png"));
add(newCityLink);
newCityLink.add(newCityImage);
return newCityLink;
}
}
So MyPage works but when I open MyOtherPage Link in an a new tab and trigger an ajax component in MyPage (e.g the AjaxButton) then I get the page expirtaion error.
Why is that happening?
Do I need to use stateless pages? ( stateless link )
Why would it be so ard in wicket to open links in new tabs and use ajax components? I must be missing sometthing..

Answer 1

Here are few possible reasons:
MyPage fails to serialize
Wicket stores stateful pages in page storage (in the disk, by default). Later when you click a stateful link Wicket tries to load the page. First it looks in the http session where the page is kept in its live form (i.e. not serialized). If it is not found there then Wicket looks in the disk.
Wicket keeps only the page(s) used in the last user request in the Http Session (to keep memory footprint small). By clicking on MyOtherPage link you put an instance of MyOtherPage in the Http session and the old instance (of MyPage) is only in the disk. But: if MyPage fails to serialize to byte[] then it cannot be stored in the disk and thus later requests will fail with PageExpiredException.
Todo: Check your logs for NotSerializableException with nice debug message of the reason.
MyOtherPage is too big
By default Wicket writes up to 10M per user session in the disk. If MyPage is let's say 2M and MyOtherPage is 9M (both sizes are quite big, but I don't know what happens in your app...) then saving MyOtherPage will remove MyPage from the disk. Later attempts to load MyPage will fail with PageExpiredException.
Todo: Review your usage of Wicket Models.