com.google.gerrit.server.mail.send.CommentFormatter Maven / Gradle / Ivy
// Copyright (C) 2016 The Android Open Source Project
//
// Licensed 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 com.google.gerrit.server.mail.send;
import static com.google.common.base.Strings.isNullOrEmpty;
import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableList;
import com.google.gerrit.common.Nullable;
import java.util.ArrayList;
import java.util.List;
public class CommentFormatter {
public enum BlockType {
LIST,
PARAGRAPH,
PRE_FORMATTED,
QUOTE
}
public static class Block {
public BlockType type;
public String text;
public List items; // For the items of list blocks.
public List quotedBlocks; // For the contents of quote blocks.
}
/**
* Take a string of comment text that was written using the wiki-Like format and emit a list of
* blocks that can be rendered to block-level HTML. This method does not escape HTML.
*
* Adapted from the {@code wikify} method found in:
* com.google.gwtexpui.safehtml.client.SafeHtml
*
* @param source The raw, unescaped comment in the Gerrit wiki-like format.
* @return List of block objects, each with unescaped comment content.
*/
public static ImmutableList parse(@Nullable String source) {
if (isNullOrEmpty(source)) {
return ImmutableList.of();
}
ImmutableList.Builder result = ImmutableList.builder();
for (String p : Splitter.on("\n\n").split(source)) {
if (isQuote(p)) {
result.add(makeQuote(p));
} else if (isPreFormat(p)) {
result.add(makePre(p));
} else if (isList(p)) {
makeList(p, result);
} else if (!p.isEmpty()) {
result.add(makeParagraph(p));
}
}
return result.build();
}
/**
* Take a block of comment text that contains a list and potentially paragraphs (but does not
* contain blank lines), generate appropriate block elements and append them to the output list.
*
* In simple cases, this will generate a single list block. For example, on the following
* input.
*
*
* Item one. * Item two. * item three.
*
*
However, if the list is adjacent to a paragraph, it will need to also generate that
* paragraph. Consider the following input.
*
*
A bit of text describing the context of the list: * List item one. * List item two. * Et
* cetera.
*
*
In this case, {@code makeList} generates a paragraph block object containing the
* non-bullet-prefixed text, followed by a list block.
*
*
Adapted from the {@code wikifyList} method found in:
* com.google.gwtexpui.safehtml.client.SafeHtml
*
* @param p The block containing the list (as well as potential paragraphs).
* @param out The list of blocks to append to.
*/
private static void makeList(String p, ImmutableList.Builder out) {
Block block = null;
StringBuilder textBuilder = null;
boolean inList = false;
boolean inParagraph = false;
for (String line : Splitter.on('\n').split(p)) {
if (line.startsWith("-") || line.startsWith("*")) {
// The next line looks like a list item. If not building a list already,
// then create one. Remove the list item marker (* or -) from the line.
if (!inList) {
if (inParagraph) {
// Add the finished paragraph block to the result.
inParagraph = false;
block.text = textBuilder.toString();
out.add(block);
}
inList = true;
block = new Block();
block.type = BlockType.LIST;
block.items = new ArrayList<>();
}
line = line.substring(1).trim();
} else if (!inList) {
// Otherwise, if a list has not yet been started, but the next line does
// not look like a list item, then add the line to a paragraph block. If
// a paragraph block has not yet been started, then create one.
if (!inParagraph) {
inParagraph = true;
block = new Block();
block.type = BlockType.PARAGRAPH;
textBuilder = new StringBuilder();
} else {
textBuilder.append(" ");
}
textBuilder.append(line);
continue;
}
block.items.add(line);
}
if (block != null) {
out.add(block);
}
}
private static Block makeQuote(String p) {
String quote = p.replaceAll("\n\\s?>\\s?", "\n");
if (quote.startsWith("> ")) {
quote = quote.substring(2);
} else if (quote.startsWith(" > ")) {
quote = quote.substring(3);
}
Block block = new Block();
block.type = BlockType.QUOTE;
block.quotedBlocks = CommentFormatter.parse(quote);
return block;
}
private static Block makePre(String p) {
Block block = new Block();
block.type = BlockType.PRE_FORMATTED;
block.text = p;
return block;
}
private static Block makeParagraph(String p) {
Block block = new Block();
block.type = BlockType.PARAGRAPH;
block.text = p;
return block;
}
private static boolean isQuote(String p) {
return p.startsWith("> ") || p.startsWith(" > ");
}
private static boolean isPreFormat(String p) {
return p.startsWith(" ") || p.startsWith("\t") || p.contains("\n ") || p.contains("\n\t");
}
private static boolean isList(String p) {
return p.startsWith("- ") || p.startsWith("* ") || p.contains("\n- ") || p.contains("\n* ");
}
}