MetaDataLocator Usage

Module.java

  public static void contributeMetaWorker(MappedConfiguration<Class, MetaDataExtractor> configuration) {
    // register meta extractor for @RequireSession annotation
    configuration.addInstance(RequireSession.class, RequireSessionExtractor.class);
  }

RequireSessionExtractor.java

public class RequireSessionExtractor implements MetaDataExtractor<RequireSession> {
  public static final String VALUE_KEY = "require-session-value";
  public static final String REDIRECT_PAGE_KEY = "require-session-redirect-page";

  public void extractMetaData(final MutableComponentModel model, final RequireSession annotation) {
    // cache meta values in component model
    model.setMeta(VALUE_KEY, annotation.value().getName());
    model.setMeta(REDIRECT_PAGE_KEY, annotation.redirectPage());
  }
}

RequireSessionFilter.java

public class RequireSessionFilter implements ComponentRequestFilter {

  private Response response;
  private ApplicationStateManager applicationStateManager;
  private PageRenderLinkSource pageRenderLinkSource;
  private MetaDataLocator metaDataLocator;

  public RequireSessionFilter(Response response,
                              ApplicationStateManager applicationStateManager,
                              PageRenderLinkSource pageRenderLinkSource,
                              MetaDataLocator metaDataLocator) {
    this.response = response;
    this.applicationStateManager = applicationStateManager;
    this.pageRenderLinkSource = pageRenderLinkSource;
    this.metaDataLocator = metaDataLocator;
  }

  public void handleComponentEvent(ComponentEventRequestParameters parameters, ComponentRequestHandler handler)
      throws IOException {
    if (redirectIfObjectNotInSession(parameters.getActivePageName())) {
      return;
    }

    handler.handleComponentEvent(parameters);
  }

  public void handlePageRender(PageRenderRequestParameters parameters, ComponentRequestHandler handler)
      throws IOException {
    if (redirectIfObjectNotInSession(parameters.getLogicalPageName())) {
      return;
    }

    handler.handlePageRender(parameters);
  }

  private boolean redirectIfObjectNotInSession(String pageName)
      throws IOException {
    // find meta in component model
    final Class<?> stateClass = metaDataLocator.findMeta(RequireSessionExtractor.VALUE_KEY, pageName, Class.class);
    if (stateClass != null && !applicationStateManager.exists(stateClass)) {
      final String redirectPage = metaDataLocator.findMeta(RequireSessionExtractor.REDIRECT_PAGE_KEY, pageName, String.class);
      final Link redirectPageLink = pageRenderLinkSource.createPageRenderLink(redirectPage);
      response.sendRedirect(redirectPageLink);
      return true;
    }
    return false;
  }
}

Uhm .. should work fine, but looks like my expectedObjectInSession is a custom Object ( of class UserInfo ), a container bean.

And this does not work properly, as it can't find a Coercion from java.lang.String ( the name ) to java.lang.Class ( the bean type?)

Thanks anyway.

Sorry, I didn't try to run this example, just wrote a piece of code. You can add coercion from String to Class to fix this issue.