/*
* See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.xwiki.rendering.wikimodel.impl;
import java.util.List;
import org.xwiki.rendering.wikimodel.WikiParameter;
/**
* This class contains some utility methods used by scanners.
*
* @version $Id: 712fba3ebe77aad51abf943a66a44c38eec2025b $
* @since 4.0M1
*/
public class WikiScannerUtil
{
/**
* The default character to use has escaping char.
*/
private static final char DEFAULT_ESCAPECHAR = '\u005c\u005c';
/**
* Extracts and returns a substring of the given string starting from the
* given open sequence and finishing by the specified close sequence. This
* method unescapes all symbols prefixed by the given escape symbol.
*
* @param str from this string the substring framed by the specified open
* and close sequence will be returned
* @param open the start substring sequence
* @param close the closing substring sequence
* @return a substring of the given string starting from the given open
* sequence and finishing by the specified close sequence
*/
public static String extractSubstring(String str, String open, String close)
{
return extractSubstring(str, open, close, DEFAULT_ESCAPECHAR, true);
}
/**
* Extracts and returns a substring of the given string starting from the
* given open sequence and finishing by the specified close sequence. This
* method unescapes all symbols prefixed by the given escape symbol.
*
* @param str from this string the substring framed by the specified open
* and close sequence will be returned
* @param open the start substring sequence
* @param close the closing substring sequence
* @param escape the escape symbol
* @return a substring of the given string starting from the given open
* sequence and finishing by the specified close sequence
*/
public static String extractSubstring(
String str,
String open,
String close,
char escape)
{
return extractSubstring(str, open, close, escape, true);
}
/**
* Extracts and returns a substring of the given string starting from the
* given open sequence and finishing by the specified close sequence. This
* method unescapes all symbols prefixed by the given escape symbol.
*
* @param str from this string the substring framed by the specified open
* and close sequence will be returned
* @param open the start substring sequence
* @param close the closing substring sequence
* @param escape the escape symbol
* @param cleanEscape indicate if the escaping char has to be removed.
* Useful when the substring use the same escaping that the string.
* @return a substring of the given string starting from the given open
* sequence and finishing by the specified close sequence
*/
public static String extractSubstring(
String str,
String open,
String close,
char escape,
boolean cleanEscape)
{
int i;
StringBuffer buf = new StringBuffer();
int len = str.length();
for (i = 0; i < len; i++) {
if (str.startsWith(open, i)) {
i += open.length();
break;
}
}
boolean escaped = false;
for (; i < len; i++) {
if (escaped) {
char ch = str.charAt(i);
buf.append(ch);
escaped = false;
} else {
if (str.startsWith(close, i)) {
break;
}
char ch = str.charAt(i);
escaped = ch == escape;
if (!escaped || !cleanEscape) {
buf.append(ch);
}
}
}
return buf.toString();
}
/**
* This method copies to the given buffer all characters from the specified
* position of the character array to the next delimiter position. This
* method returns the next position just after the delimiter (or the length
* of the array if no delimiters was found).
*
* @param array the array of character used as a source of chars
* @param pos the start position in the array
* @param delimiter the delimiter; this method copies all character from the
* current position to the first delimiter sequence
* @param buf the buffer where the content should be appended
* @return the next position just after the delimiter of the end of the
* sequence
*/
public static int getNextSequence(
char[] array,
int pos,
char[] delimiter,
StringBuffer buf)
{
buf.delete(0, buf.length());
char quot = 0;
for (; pos < array.length; pos++) {
char ch = array[pos];
if (quot != 0) {
if (ch == quot) {
quot = 0;
}
} else {
if (ch == '\"') {
quot = ch;
} else {
// Checks if a new delimiter sequence was found in the
// current position
int i = skipSequence(array, pos, delimiter);
if (i > pos) {
pos = i;
break;
}
}
}
buf.append(ch);
}
return pos;
}
/**
* @param array from this array of bytes the next token will be returned
* @param pos the current position in the array of bytes
* @param buf to this buffer the extracted token value will be appended
* @param trim this array is used to return the boolean flag specifying if
* the value collected in the buffer should be trimmed or not
* @param escapeChar the escaping character
* @return the new position in the array after extracting of a new token
*/
private static int getNextToken(
char[] array,
int pos,
char[] delimiter,
StringBuffer buf,
boolean[] trim,
char escapeChar)
{
buf.delete(0, buf.length());
boolean escaped = false;
if (pos < array.length && (array[pos] == '\'' || array[pos] == '"')) {
trim[0] = false;
char endChar = array[pos];
pos++;
for (; pos < array.length && (escaped || array[pos] != endChar); pos++) {
if (escaped) {
buf.append(array[pos]);
escaped = false;
} else {
escaped = array[pos] == escapeChar;
if (!escaped) {
buf.append(array[pos]);
}
}
}
if (pos < array.length) {
pos++;
}
} else {
trim[0] = true;
for (; pos < array.length; pos++) {
if (escaped) {
buf.append(array[pos]);
escaped = false;
} else {
if ((array[pos] == '=' || skipSequence(
array,
pos,
delimiter) > pos))
{
break;
}
if (array[pos] == '\'' || array[pos] == '"') {
break;
}
escaped = array[pos] == escapeChar;
if (!escaped) {
buf.append(array[pos]);
}
}
}
}
return pos;
}
/**
* Indicate if the specified sequence starts from the given position in the
* character array.
*
* @param array the array of characters
* @param arrayPos the position of the first character in the array;
* starting from this position the sequence should be skipped
* @param sequence the sequence of characters to match
* @return true if the sequence is found, false otherwise
*/
public static boolean matchesSequence(
char[] array,
int arrayPos,
char[] sequence)
{
int i;
int j;
for (i = arrayPos, j = 0; i < array.length && j < sequence.length; i++, j++) {
if (array[i] != sequence[j]) {
break;
}
}
return j == sequence.length;
}
/**
* Moves forward the current position in the array until the first not empty
* character is found.
*
* @param array the array of characters where the spaces are searched
* @param pos the current position in the array; starting from this position
* the spaces will be searched
* @param buf to this buffer all not empty characters will be added
* @return the new position int the array of characters
*/
private static int removeSpaces(char[] array, int pos, StringBuffer buf)
{
buf.delete(0, buf.length());
for (; pos < array.length
&& (array[pos] == '=' || Character.isSpaceChar(array[pos])); pos++)
{
if (array[pos] == '=') {
buf.append(array[pos]);
}
}
return pos;
}
/**
* Skips the specified sequence if it starts from the given position in the
* character array.
*
* @param array the array of characters
* @param arrayPos the position of the first character in the array;
* starting from this position the sequence should be skipped
* @param sequence the sequence of characters to skip
* @return a new value of the character counter
*/
public static int skipSequence(char[] array, int arrayPos, char[] sequence)
{
int i;
int j;
for (i = arrayPos, j = 0; i < array.length && j < sequence.length; i++, j++) {
if (array[i] != sequence[j]) {
break;
}
}
return j == sequence.length ? i : arrayPos;
}
/**
* Splits the given string into a set of key-value pairs; all extracted
* values will be added to the given list
*
* @param str the string to split
* @param list to this list all extracted values will be added
*/
public static int splitToPairs(String str, List<WikiParameter> list)
{
return splitToPairs(str, list, null);
}
public static int splitToPairs(
String str,
List<WikiParameter> list,
char escapeChar)
{
return splitToPairs(str, list, null, null, escapeChar);
}
/**
* Splits the given string into a set of key-value pairs; all extracted
* values will be added to the given list
*
* @param str the string to split
* @param list to this list all extracted values will be added
* @param delimiter a delimiter for individual key/value pairs
*/
public static int splitToPairs(
String str,
List<WikiParameter> list,
String delimiter)
{
return splitToPairs(str, list, delimiter, null);
}
public static int splitToPairs(
String str,
List<WikiParameter> list,
String delimiter,
String end)
{
return splitToPairs(str, list, delimiter, end, DEFAULT_ESCAPECHAR);
}
/**
* Splits the given string into a set of key-value pairs; all extracted
* values will be added to the given list
*
* @param str the string to split
* @param list to this list all extracted values will be added
* @param delimiter a delimiter for individual key/value pairs
* @param end the ending sequence, if null it's not taken into account
* @param escapeChar the escaping character
* @return the index where parser stopped
*/
public static int splitToPairs(
String str,
List<WikiParameter> list,
String delimiter,
String end,
char escapeChar)
{
if (str == null) {
return 0;
}
char[] array = str.toCharArray();
if (delimiter == null) {
delimiter = " ";
}
char[] delimiterArray = delimiter.toCharArray();
char[] endArray = end != null ? end.toCharArray() : new char[0];
StringBuffer buf = new StringBuffer();
int i = 0;
boolean[] trim = {false};
for (; i < array.length; ) {
String key = null;
String value = null;
i = removeSpaces(array, i, buf);
if (i >= array.length) {
break;
}
int prev = i;
i = skipSequence(array, i, delimiterArray);
if (i >= array.length) {
break;
}
if (i > prev) {
i = removeSpaces(array, i, buf);
if (i >= array.length) {
break;
}
}
// if provided ending sequence is found, we stop parsing
if (end != null && matchesSequence(array, i, endArray)) {
break;
}
i = getNextToken(array, i, delimiterArray, buf, trim, escapeChar);
key = buf.toString().trim();
i = removeSpaces(array, i, buf);
if (buf.indexOf("=") >= 0) {
i = getNextToken(
array,
i,
delimiterArray,
buf,
trim,
escapeChar);
value = buf.toString();
if (trim[0]) {
value = value.trim();
}
}
WikiParameter entry = new WikiParameter(key, value);
list.add(entry);
}
return i;
}
/**
* Unescapes the given string and returns the result. This method uses the
* default escape symbol (see {@link #DEFAULT_ESCAPECHAR}).
*
* @param str the string to unescape
* @return an unescaped string
*/
public static String unescape(String str)
{
return unescape(str, DEFAULT_ESCAPECHAR);
}
/**
* Unescapes the given string and returns the result.
*
* @param str the string to unescape
* @param escape the symbol used to escape characters
* @return an unescaped string
*/
public static String unescape(String str, char escape)
{
if (str == null) {
return "";
}
StringBuffer buf = new StringBuffer();
char[] array = str.toCharArray();
boolean escaped = false;
for (int i = 0; i < array.length; i++) {
char ch = array[i];
if (escaped) {
buf.append(ch);
escaped = false;
} else {
escaped = (ch == escape);
if (!escaped) {
buf.append(ch);
}
}
}
return buf.toString();
}
}