org.apache.wicket.markup.html.basic.Label.java Source code

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Here is the source code for org.apache.wicket.markup.html.basic.Label.java

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/*
 * 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.basic;

import java.io.Serializable;

import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.MarkupStream;
import org.apache.wicket.markup.html.WebComponent;
import org.apache.wicket.markup.parser.XmlTag.TagType;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.Model;

/**
 * A Label component replaces its body with the String version of its model object returned by
 * getModelObjectAsString().
 * <p>
 * Exactly what is displayed as the body, depends on the model. The simplest case is a Label with a
 * static String model, which can be constructed like this:
 * 
 * <pre>
 * add(new Label(&quot;myLabel&quot;, &quot;the string to display&quot;))
 * </pre>
 * 
 * A Label with a dynamic model can be created like this:
 * 
 * <pre>
 * 
 *       add(new Label(&quot;myLabel&quot;, new PropertyModel(person, &quot;name&quot;));
 * 
 * </pre>
 * 
 * In this case, the Label component will replace the body of the tag it is attached to with the
 * 'name' property of the given Person object, where Person might look like:
 * 
 * <pre>
 * public class Person
 * {
 *    private String name;
 * 
 *    public String getName()
 *    {
 *       return name;
 *    }
 * 
 *    public void setName(String name)
 *    {
 *       this.name = name;
 *    }
 * }
 * </pre>
 * 
 * @author Jonathan Locke
 */
public class Label extends WebComponent {
    private static final long serialVersionUID = 1L;

    /**
     * Constructor
     * 
     * @param id
     *            See Component
     */
    public Label(final String id) {
        super(id);
    }

    /**
     * Convenience constructor. Same as Label(String, Model.of(Serializable))
     * 
     * @param id
     *            See Component
     * @param label
     *            The label text or object, converted to a string via the {@link org.apache.wicket.util.convert.IConverter}.
     * 
     * @see org.apache.wicket.Component#Component(String, IModel)
     */
    public Label(final String id, Serializable label) {
        this(id, Model.of(label));
    }

    /**
     * @param id
     * @param model
     * @see org.apache.wicket.Component#Component(String, IModel)
     */
    public Label(final String id, IModel<?> model) {
        super(id, model);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void onComponentTagBody(final MarkupStream markupStream, final ComponentTag openTag) {
        replaceComponentTagBody(markupStream, openTag, getDefaultModelObjectAsString());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void onComponentTag(ComponentTag tag) {
        super.onComponentTag(tag);

        if (tag.isOpenClose()) {
            // always transform the tag to <span></span> so even labels defined as <span/> render
            tag.setType(TagType.OPEN);
        }
    }
}