org.apache.wicket.markup.html.form.AutoLabelTextResolver Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of wicket-core Show documentation
Wicket is a Java web application framework that takes simplicity, separation of concerns and ease of development to a whole new level. Wicket pages can be mocked up, previewed and later revised using standard WYSIWYG HTML design tools. Dynamic content processing and form handling is all handled in Java code using a first-class component model backed by POJO data beans that can easily be persisted using your favorite technology.
There is a newer version: 10.0.0
Show newest version
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.wicket.markup.html.form;

import org.apache.wicket.Component;
import org.apache.wicket.MarkupContainer;
import org.apache.wicket.core.request.handler.ComponentNotFoundException;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.MarkupStream;
import org.apache.wicket.markup.WicketTag;
import org.apache.wicket.markup.html.WebMarkupContainer;
import org.apache.wicket.markup.html.basic.Label;
import org.apache.wicket.markup.html.form.AutoLabelResolver.AutoLabel;
import org.apache.wicket.markup.html.internal.ResponseBufferZone;
import org.apache.wicket.markup.parser.XmlTag;
import org.apache.wicket.markup.resolver.IComponentResolver;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.LoadableDetachableModel;
import org.apache.wicket.model.Model;
import org.apache.wicket.model.StringResourceModel;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.util.string.Strings;

/**
 * Resolver that provides the {@literal } tag, which will output a
 * FormComponent's {@link FormComponent#getLabel() label} without requiring a manual extra component
 * such as {@link Label} or {@link FormComponentLabel}.
 * 
 * {@literal } can be used
 * 
 * together with {@literal }:
 * 
 *  * {@literal
 * some other markup, optionally
 * }
 * 
 * 
 * 
 * 
 * standalone, with a for attribute:
 * 
 *  * {@literal
 * 
 * }
 * 
 * 
 * 
 * 
 * 
 * It also supports both input and output:
 * 

 * If the FormComponent has a label model, the {@literal } tag will
 * be replaced by the contents of that label.
 * If the FormComponent's label model is null, it can be picked up from
 * {@literal }:
 * 
 * {@literal } can contain some raw markup, like this:
 * 
 *  * {@literal
 * I will become the component's label!
 * }
 * 
 * 
 * 
 * Or it can be a message pulled from resources, similar to
 * {@literal }:
 * 
 *  * {@literal
 * 
 * }
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * @author Carl-Eric Menzel 
 * @author igor
 */
public class AutoLabelTextResolver implements IComponentResolver
{
	public static final String LABEL = "label";

	/**
	 * This is inserted by the resolver to render the label.
	 */
	private static class TextLabel extends WebMarkupContainer
	{

		private final Component labeled;

		public TextLabel(String id, Component labeled)

		{
			super(id);
			this.labeled = labeled;
			setRenderBodyOnly(true);
		}

		@Override
		protected void onComponentTag(final ComponentTag tag)
		{
			if (tag.isOpenClose())
			{
				tag.setType(XmlTag.TagType.OPEN);
			}
			super.onComponentTag(tag);
		}

		@Override
		public void onComponentTagBody(final MarkupStream markupStream, final ComponentTag openTag)
		{

			// try and find some form of label content...
			IModel labelModel = findLabelContent(markupStream, openTag);
			// print the label text
			replaceComponentTagBody(markupStream, openTag,
				labelModel != null ? labelModel.getObject() : "");

			// store the label text in FormComponent's label model so its available to errors
			if (labelModel != null)
			{
				if (labeled instanceof FormComponent)
				{
					FormComponent fc = (FormComponent)labeled;
					fc.setLabel(labelModel);
				}
				else
				{
					// if we can't hand off the labelmodel to a component, we have to detach it
					labelModel.detach();
				}
			}
		}

		private IModel findLabelContent(final MarkupStream markupStream,
			final ComponentTag tag)
		{
			if (labeled instanceof ILabelProvider)
			{
				// check if the labeled component is a label provider
				ILabelProvider provider = (ILabelProvider)labeled;
				if (provider.getLabel() != null)
				{
					if (!Strings.isEmpty(provider.getLabel().getObject()))

					{
						return provider.getLabel();
					}
				}
			}

			// check if the labeled component is a form component
			if (labeled instanceof FormComponent)
			{
				final FormComponent formComponent = (FormComponent)labeled;
				String text = formComponent.getDefaultLabel("wicket:unknown");
				if (!"wicket:unknown".equals(text) && !Strings.isEmpty(text))
				{
					return new LoadableDetachableModel()
					{
						@Override
						protected String load()
						{
							return formComponent.getDefaultLabel("wicket:unknown");
						}
					};
				}
			}

			// check if wicket:label tag has a message key
			{
				String resourceKey = tag.getAttribute("key");
				if (resourceKey != null)
				{
					String text = labeled.getString(resourceKey);
					if (!Strings.isEmpty(text))
					{
						return new StringResourceModel(resourceKey, labeled, null);
					}
				}
			}

			// as last resort use the tag body
			{
				String text = new ResponseBufferZone(RequestCycle.get(), markupStream)
				{
					@Override
					protected void executeInsideBufferedZone()
					{
						TextLabel.super.onComponentTagBody(markupStream, tag);
					}
				}.execute().toString();

				if (!Strings.isEmpty(text))
				{
					return Model.of(text);
				}
			}

			return null;
		}
	}

	@Override
	public Component resolve(MarkupContainer container, MarkupStream markupStream, ComponentTag tag)
	{
		if (tag instanceof WicketTag && "label".equals(tag.getName()))
		{
			// We need to find a FormComponent...
			Component related = null;
			// ...which could be explicitly specified...
			String forAttributeValue = tag.getAttribute("for");
			if (forAttributeValue != null)
			{
				Component component = AutoLabelResolver.findRelatedComponent(container, forAttributeValue);
				related = component;
			}
			if (related == null)
			{
				// ...or available through an AutoLabel, either directly above us...
				if (container instanceof AutoLabel)
				{
					related = ((AutoLabel)container).getRelatedComponent();
				}
				if (related == null)
				{
					// ...or perhaps further up...
					AutoLabel autoLabel = container.findParent(AutoLabel.class);
					if (autoLabel != null)
					{
						related = autoLabel.getRelatedComponent();
					}
				}
			}
			if (related == null)
			{
				// ...or it might just not be available.
				String forAttr = forAttributeValue != null ? " for=\"" + forAttributeValue + "\"" : "";
				throw new ComponentNotFoundException("no related component found for ");
			}
			else
			{
				// ...found the form component, so we can return our label.
				return new TextLabel("label" + container.getPage().getAutoIndex(), related);
			}
		}
		return null;
	}

}