ContainerDescendentReporter.java

import org.apache.wicket.MarkupContainer;
import org.apache.wicket.Component;
import org.apache.wicket.util.tester.WicketTester;

import java.util.List;
import java.util.ArrayList;

/**
 * Provides a method to get a list or descriptive string of descendants
 * of a container, with their wicket ID's, and class types.
 */
public class ContainerDescendantReporter {


    /**
     * For the specified container Wicked id path, returns a string containing,
     * for each descendant component, the Wicket id path and the class
     * of the component.  Note that although it is possible to find descendants
     * for a MarkupContainer with getReportString(MarkupContainer), it is
     * not possible to do so with this method, since this method looks for
     * Components, not MarkupContainers.
     *
     * Uses WicketTester.getComponentFromLastRenderedPage().
     *
     * @param wicketIdPath id path of the container, relative to the page
     *        can be "" to specify the page
     * @param tester
     */
    public static String getReportString(String wicketIdPath, WicketTester tester) {

        return getReportString(
                (MarkupContainer) tester.getComponentFromLastRenderedPage(wicketIdPath));
    }

    
    /**
     * For the specified container, returns a string containing, for each
     * descendant component, the Wicket id path and the class of the component.
     *
     * @param markupContainer
     */
    public static String getReportString(MarkupContainer markupContainer) {
        StringBuffer sbuf = new StringBuffer();

        sbuf.append("\n\nDescendants:\n");
        {
            List<Component> formComponents = getDescendantComponents(markupContainer);
            for (Component c : formComponents) {
                sbuf.append(c.getPageRelativePath()).append(":    ")
                        .append(c.getClass().getName()).append('\n');
            }
        }

        return sbuf.toString();
    }


    /**
     * Gets a list of descendant components in this container.  For example:
     *
     * MarkupContainer form = (MarkupContainer) tester.getComponentFromLastRenderedPage("form");
     * List<Component> formComponents = tester.getDescendantComponents(form);
     *
     * @param markupContainer the container (e.g. Panel)
     * @return list of components (goes all levels down the hierarchy)
     */
    public static List<Component> getDescendantComponents(MarkupContainer markupContainer) {
        DescendantCollector childCollector = new DescendantCollector();
        markupContainer.visitChildren(childCollector);
        return childCollector.getChildren();
    }


    /**
     * Gets a list of descendant components in the container at the specified path.
     * For example:
     *
     * List<Component> formComponents = tester.getDescendantComponents(wicketIdPath , tester);
     *
     * @param wicketIdPath id path of the container, relative to the page
     *        can be "" to specify the page
     * @param tester
     *
     * @return list of components (goes all levels down the hierarchy)
     */
    public static List<Component> getDescendantComponents(String wicketIdPath, WicketTester tester) {
        return getDescendantComponents(
                (MarkupContainer) tester.getComponentFromLastRenderedPage(wicketIdPath));
    }


    /**
     * Uses the visitor pattern to accumulate a list of all child
     * components of a MarkupContainer.
     *
     * Used by getDescendantComponents().
     */
    private static class DescendantCollector implements Component.IVisitor<Component> {

        private List<Component> components = new ArrayList<Component>();

        public Object component(Component component) {
            components.add(component);
            return CONTINUE_TRAVERSAL;
        }

        public List<Component> getChildren() {
            return components;
        }
    }
}