flink-core/src/main/java/org/apache/flink/configuration/description/HtmlFormatter.java

/*
 * 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.flink.configuration.description;

import java.util.EnumSet;

/**
 * Formatter that transforms {@link Description} into Html representation.
 */
public class HtmlFormatter extends Formatter {

	@Override
	protected void formatLink(StringBuilder state, String link, String description) {
		state.append(String.format("<a href=\"%s\">%s</a>", link, description));
	}

	@Override
	protected void formatLineBreak(StringBuilder state) {
		state.append("<br/>");
	}

	@Override
	protected void formatText(
			StringBuilder state,
			String format,
			String[] elements,
			EnumSet<TextElement.TextStyle> styles) {
		String escapedFormat = escapeCharacters(format);

		String prefix = "";
		String suffix = "";
		if (styles.contains(TextElement.TextStyle.CODE)) {
			prefix = "<span markdown=\"span\">`";
			suffix = "`</span>";
		}
		state.append(prefix);
		state.append(String.format(escapedFormat, elements));
		state.append(suffix);
	}

	@Override
	protected void formatList(StringBuilder state, String[] entries) {
		state.append("<ul>");
		for (String entry : entries) {
			state.append(String.format("<li>%s</li>", entry));
		}
		state.append("</ul>");
	}

	@Override
	protected Formatter newInstance() {
		return new HtmlFormatter();
	}

	private static String escapeCharacters(String value) {
		return value
			.replaceAll("<", "&lt;")
			.replaceAll(">", "&gt;");
	}

}