TabGroup tapestry component for use with twitter-bootstrap CSS.

Tab.java

package mypackage.components;

import javax.inject.Inject;

import org.apache.tapestry5.BindingConstants;
import org.apache.tapestry5.ComponentResources;
import org.apache.tapestry5.annotations.Parameter;
import org.apache.tapestry5.annotations.SetupRender;
import org.apache.tapestry5.services.Request;
import mypackage.TabModel;

/**
 * NB: I would have preferred to use an Environmental instead of a request attribute but I can't
 * http://tapestry.1045711.n5.nabble.com/5-4-alpha-2-Environment-cloaked-during-ajax-component-event-td5719496.html
 */
public class Tab {
	@Parameter(required = true, defaultPrefix = BindingConstants.LITERAL)
	private String label;
	
	@Inject
	private ComponentResources componentResources;
	
	@Inject 
	private Request request;
	
	@SetupRender
	boolean setupRender() {
		TabModel tabModel = (TabModel) request.getAttribute(TabGroup.ATTRIBUTE_TAB_MODEL);
		if (tabModel == null) {
			throw new IllegalStateException("Tab must be nested inside a TabGroup");
		}
		tabModel.getLabelsById().put(componentResources.getId(), label);
		
		// the active tab's body will be rendered by the TabGroup
		return false;
	}
}

TabGroup.java

package mypackage.components;

import java.util.Map;

import org.apache.tapestry5.BindingConstants;
import org.apache.tapestry5.Block;
import org.apache.tapestry5.ComponentResources;
import org.apache.tapestry5.annotations.CleanupRender;
import org.apache.tapestry5.annotations.InjectComponent;
import org.apache.tapestry5.annotations.Parameter;
import org.apache.tapestry5.annotations.Property;
import org.apache.tapestry5.annotations.SetupRender;
import org.apache.tapestry5.corelib.components.Zone;
import org.apache.tapestry5.ioc.annotations.Inject;
import org.apache.tapestry5.runtime.Component;
import org.apache.tapestry5.services.Request;
import mypackage.model.TabModel;

/**
 * NB: I would have preferred to use an Environmental instead of a request attribute but I can't
 * http://tapestry.1045711.n5.nabble.com/5-4-alpha-2-Environment-cloaked-during-ajax-component-event-td5719496.html
 */
public class TabGroup {
	public static final String ATTRIBUTE_TAB_MODEL = TabGroup.class.getName() + ".TAB_MODEL";
	
	@Inject
	private Request request;
	
	@Property
	private TabModel tabModel;
	
	@Property
	private Map.Entry<String, String> tabEntry;
	
	@Parameter(required=true, defaultPrefix=BindingConstants.LITERAL)
	private String active;
	
	@Property
	private String mutableActive;
	
	@InjectComponent
	private Zone tabsZone;
	
	@SetupRender
	void setupRender() {
		mutableActive = active;
		setup();
	}
	
	@Inject
	private ComponentResources componentResources;
	
	void setup() {
		tabModel = new TabModel();
		request.setAttribute(ATTRIBUTE_TAB_MODEL, tabModel);
	}
	
	@CleanupRender
	void cleanupRender() {
		request.setAttribute(ATTRIBUTE_TAB_MODEL, null);
	}
	
	Block onTabChange(String tabId) {
		mutableActive = tabId;
		setup();
		return tabsZone.getBody();
	}
	
	public String getTabClass() {
		return tabEntry.getKey().equals(mutableActive) ? "active" : null;
	}
	
	public Block getActiveTabBody() {
		Component component = componentResources.getContainerResources().getEmbeddedComponent(mutableActive);
		return component.getComponentResources().getBody();
	}
}

TabGroup.tml

<t:zone t:id="tabsZone" xmlns:t="http://tapestry.apache.org/schema/tapestry_5_3.xsd" xmlns:p="tapestry:parameter">
	<t:delegate to="componentResources.body" />
	<ul class="nav nav-tabs">
		<t:loop source="tabModel.labelsById.entrySet()" value="tabEntry">
		 	<li class="${tabClass}">
		 		<t:eventlink event="tabChange" context="tabEntry.key" zone="^">${tabEntry.value}</t:eventlink>
		 	</li>
		</t:loop>
	</ul>
	<t:delegate to="activeTabBody" />
</t:zone>

TabModel.java

package mypackage.model;

import java.util.LinkedHashMap;
import java.util.Map;

public class TabModel {
	private Map<String, String> labelsById = new LinkedHashMap<String, String>();
	
	public Map<String, String> getLabelsById() {
		return labelsById;
	}
}