juneau-core/juneau-marshall/src/main/java/org/apache/juneau/html/HtmlRender.java

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package org.apache.juneau.html;

import org.apache.juneau.html.annotation.*;
import org.apache.juneau.serializer.*;

/**
 * Allows custom rendering of bean property values when serialized as HTML.
 *
 * <p>
 * Associated with bean properties using the {@link Html#render() @Html(render)} annotation.
 *
 * <p>
 * Using this class, you can alter the CSS style and HTML content of the bean property.
 *
 * <ul class='seealso'>
 * 	<li class='link'>{@doc juneau-marshall.HtmlDetails.HtmlRenderAnnotation}
 * </ul>
 *
 * @param <T> The bean property type.
 */
public abstract class HtmlRender<T> {

	/**
	 * Returns the CSS style of the element containing the bean property value.
	 *
	 * @param session
	 * 	The current serializer session.
	 * 	Can be used to retrieve properties and session-level information.
	 * @param value The bean property value.
	 * @return The CSS style string, or <jk>null</jk> if no style should be added.
	 */
	public String getStyle(SerializerSession session, T value) {
		return null;
	}

	/**
	 * Returns the delegate value for the specified bean property value.
	 *
	 * <p>
	 * The default implementation simply returns the same value.
	 * A typical use is to return an HTML element using one of the HTML5 DOM beans.
	 *
	 * @param session
	 * 	The current serializer session.
	 * 	Can be used to retrieve properties and session-level information.
	 * @param value The bean property value.
	 * @return The new bean property value.
	 */
	public Object getContent(SerializerSession session, T value) {
		return value;
	}
}