/**
* Copyright 2008 Google Inc.
*
* 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 org.waveprotocol.wave.model.util;
@Deprecated
public class TitleExtractor {
/**
* Extracts a title from an XML string.
* The string may be either an entire document (that contains a title
* element) or the inner XML of a title element).
*
* @param rich an XML string
* @return a title extracted from {@code rich}. The string is element-free,
* escaped XML.
*/
public static String extractTitle(String rich) {
return firstPhrase(rich);
}
/**
* Tests if an XML string contains only a title.
* Essentially, this just tests if the text view of the XML string contains
* only a single sentence.
*
* @param rich an XML string
* @return true if {@code rich} contains just a single sentence.
*/
public static boolean isOnlyTitle(String rich) {
String titleIsh = stripWhite(processForFirstPhrase(rich));
String title = extractTitle(rich);
return titleIsh.equals(title);
}
private static String firstPhrase(String rich) {
String processed = processForFirstPhrase(rich);
int stop = processed.indexOf('\n');
return stripWhite(stop != -1 ? processed.substring(0, stop) : processed);
}
private static String processForFirstPhrase(String rich) {
// Place a \n at first <br>
String text = rich.replaceFirst("<br.*?>", "\n")
// Place a \n at first closing p
.replaceFirst("</p>", "\n")
// Place a \n at first stop char, followed by whitespace
.replaceFirst("((\\.|\\?|!)+(\\s))", "$1\n");
return stripTags(text);
}
/**
* Remove opening and closing tags.
*/
private static String stripTags(String rich) {
// This was done via a rich.replaceAll("<(.|\\n)+?>", "");
// which would cause a StackOverflowError in the indexer when a root blip contained a large
// tag e.g. a gadget.
StringBuilder b = new StringBuilder();
int start = 0;
int open = rich.indexOf('<');
if (open < 0) {
return rich;
}
while(start >= 0 && start < rich.length()) {
if (open < 0) {
// Append all the rest.
b.append(rich.substring(start));
break;
}
if (open > start) {
// Append the chars between the start and the open.
b.append(rich.substring(start, open));
}
// jump to the next
start = rich.indexOf('>', open);
if (start > 0) {
// skip the '>'
++start;
}
open = rich.indexOf('<', start);
}
return b.toString();
}
/**
* Strips leading and trailing whitespace.
*/
private static String stripWhite(String text) {
return text.replaceAll("^(\\s|\u00a0)+|\\s+$", "");
}
}