com.netbout.rest.MarkdownTxtmark Maven / Gradle / Ivy
/**
* Copyright (c) 2009-2016, netbout.com
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are PROHIBITED without prior written permission from
* the author. This product may NOT be used anywhere and on any computer
* except the server platform of netbout Inc. located at www.netbout.com.
* Federal copyright law prohibits unauthorized reproduction by any means
* and imposes fines up to $25,000 for violation. If you received
* this code accidentally and without intent to use it, please report this
* incident to the author by email.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
package com.netbout.rest;
import com.github.rjeschke.txtmark.Configuration;
import com.github.rjeschke.txtmark.Processor;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.validation.constraints.NotNull;
/**
* Text with markdown formatting.
* Using TxtMark markdown processor.
*
* @author Dmitry Zaytsev ([email protected])
* @version $Id: a97263f7f82529596ebe13e167e0e50f891be152 $
* @since 2.23
*/
public final class MarkdownTxtmark implements Markdown {
/**
* Plain link detection pattern.
*/
private static final Pattern LINK = Pattern.compile(
// @checkstyle LineLengthCheck (1 line)
"(?} if the line has two or more
* spaces on its end and we should skip a line that starts with four
* or more spaces because it's a code block in markdown.
*/
private static final Pattern NEW_LINE = Pattern.compile(
"^ {0,3}(\\S|(\\S.*\\S)) ?$", Pattern.MULTILINE
);
@Override
public String html(@NotNull final String txt) {
final Configuration conf = Configuration.builder()
.enableSafeMode().build();
return Processor.process(
MarkdownTxtmark.formatLinks(MarkdownTxtmark.makeLineBreak(txt)),
conf
);
}
/**
* Replace plain links with Markdown syntax. To be convinced it doesn't
* replace links inside markdown syntax, it ensures that characters
* before and after link do not match to Markdown link syntax.
* @param txt Text to find links in
* @return Text with Markdown-formatted links
*/
private static String formatLinks(final String txt) {
final StringBuffer result = new StringBuffer();
final Matcher matcher = MarkdownTxtmark.LINK.matcher(txt);
while (matcher.find()) {
matcher.appendReplacement(
result,
String.format("[%1$s](%1$s)", matcher.group())
);
}
matcher.appendTail(result);
return result.toString();
}
/**
* Insert two spaces at the end of string that needs line break to
* force creation of HTML line break.
* @param txt Text to replace
* @return Text with Markdown-formatted links
*/
private static String makeLineBreak(final String txt) {
final StringBuffer result = new StringBuffer();
final Matcher matcher = MarkdownTxtmark.NEW_LINE.matcher(txt);
while (matcher.find()) {
if (!matcher.hitEnd()) {
matcher.appendReplacement(
result,
String.format(
"%s ", Matcher.quoteReplacement(matcher.group())
)
);
}
}
matcher.appendTail(result);
return result.toString();
}
}