/*
* Copyright 2004-2011 H2 Group. Multiple-Licensed under the H2 License,
* Version 1.0, and under the Eclipse Public License, Version 1.0
* (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.server.web;
import java.text.ParseException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.h2.util.New;
/**
* A page parser can parse an HTML page and replace the tags there.
* This class is used by the H2 Console.
*/
public class PageParser {
private String page;
private int pos;
private Map<String, Object> settings;
private int len;
private StringBuilder result;
private PageParser(String page, Map<String, Object> settings, int pos) {
this.page = page;
this.pos = pos;
this.len = page.length();
this.settings = settings;
result = new StringBuilder(len);
}
/**
* Replace the tags in the HTML page with the given settings.
*
* @param page the HTML page
* @param settings the settings
* @return the converted page
*/
public static String parse(String page, Map<String, Object> settings) {
PageParser block = new PageParser(page, settings, 0);
return block.replaceTags();
}
private void setError(int i) {
String s = page.substring(0, i) + "####BUG####" + page.substring(i);
s = PageParser.escapeHtml(s);
result = new StringBuilder();
result.append(s);
}
private String parseBlockUntil(String end) throws ParseException {
PageParser block = new PageParser(page, settings, pos);
block.parseAll();
if (!block.readIf(end)) {
throw new ParseException(page, block.pos);
}
pos = block.pos;
return block.result.toString();
}
private String replaceTags() {
try {
parseAll();
if (pos != len) {
setError(pos);
}
} catch (ParseException e) {
setError(pos);
}
return result.toString();
}
@SuppressWarnings("unchecked")
private void parseAll() throws ParseException {
StringBuilder buff = result;
String p = page;
int i = pos;
for (; i < len; i++) {
char c = p.charAt(i);
switch (c) {
case '<': {
if (p.charAt(i + 3) == ':' && p.charAt(i + 1) == '/') {
// end tag
pos = i;
return;
} else if (p.charAt(i + 2) == ':') {
pos = i;
if (readIf("<c:forEach")) {
String var = readParam("var");
String items = readParam("items");
read(">");
int start = pos;
List<Object> list = (List<Object>) get(items);
if (list == null) {
result.append("?items?");
list = New.arrayList();
}
if (list.size() == 0) {
parseBlockUntil("</c:forEach>");
}
for (Object o : list) {
settings.put(var, o);
pos = start;
String block = parseBlockUntil("</c:forEach>");
result.append(block);
}
} else if (readIf("<c:if")) {
String test = readParam("test");
int eq = test.indexOf("=='");
if (eq < 0) {
setError(i);
return;
}
String val = test.substring(eq + 3, test.length() - 1);
test = test.substring(0, eq);
String value = (String) get(test);
read(">");
String block = parseBlockUntil("</c:if>");
pos--;
if (value.equals(val)) {
result.append(block);
}
} else {
setError(i);
return;
}
i = pos;
} else {
buff.append(c);
}
break;
}
case '$':
if (p.length() > i + 1 && p.charAt(i + 1) == '{') {
i += 2;
int j = p.indexOf('}', i);
if (j < 0) {
setError(i);
return;
}
String item = p.substring(i, j).trim();
i = j;
String s = (String) get(item);
replaceTags(s);
} else {
buff.append(c);
}
break;
default:
buff.append(c);
break;
}
}
pos = i;
}
@SuppressWarnings("unchecked")
private Object get(String item) {
int dot = item.indexOf('.');
if (dot >= 0) {
String sub = item.substring(dot + 1);
item = item.substring(0, dot);
HashMap<String, Object> map = (HashMap<String, Object>) settings.get(item);
if (map == null) {
return "?" + item + "?";
}
return map.get(sub);
}
return settings.get(item);
}
private void replaceTags(String s) {
if (s != null) {
result.append(PageParser.parse(s, settings));
}
}
private String readParam(String name) throws ParseException {
read(name);
read("=");
read("\"");
int start = pos;
while (page.charAt(pos) != '"') {
pos++;
}
int end = pos;
read("\"");
String s = page.substring(start, end);
return PageParser.parse(s, settings);
}
private void skipSpaces() {
while (page.charAt(pos) == ' ') {
pos++;
}
}
private void read(String s) throws ParseException {
if (!readIf(s)) {
throw new ParseException(s, pos);
}
}
private boolean readIf(String s) {
skipSpaces();
if (page.regionMatches(pos, s, 0, s.length())) {
pos += s.length();
skipSpaces();
return true;
}
return false;
}
/**
* Convert data to HTML, but don't convert newlines and multiple spaces.
*
* @param s the data
* @return the escaped html text
*/
static String escapeHtmlData(String s) {
return escapeHtml(s, false);
}
/**
* Convert data to HTML, including newlines and multiple spaces.
*
* @param s the data
* @return the escaped html text
*/
public static String escapeHtml(String s) {
return escapeHtml(s, true);
}
private static String escapeHtml(String s, boolean convertBreakAndSpace) {
if (s == null) {
return null;
}
if (convertBreakAndSpace) {
if (s.length() == 0) {
return " ";
}
}
StringBuilder buff = new StringBuilder(s.length());
boolean convertSpace = true;
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c == ' ') {
if (convertSpace && convertBreakAndSpace) {
buff.append(" ");
} else {
buff.append(' ');
convertSpace = true;
}
continue;
}
convertSpace = false;
switch (c) {
case '$':
// so that ${ } in the text is interpreted correctly
buff.append("$");
break;
case '<':
buff.append("<");
break;
case '>':
buff.append(">");
break;
case '&':
buff.append("&");
break;
case '"':
buff.append(""");
break;
case '\'':
buff.append("'");
break;
case '\n':
if (convertBreakAndSpace) {
buff.append("<br />");
convertSpace = true;
} else {
buff.append(c);
}
break;
default:
if (c >= 128) {
buff.append("&#").append((int) c).append(';');
} else {
buff.append(c);
}
break;
}
}
return buff.toString();
}
/**
* Escape text as a the javascript string.
*
* @param s the text
* @return the javascript string
*/
static String escapeJavaScript(String s) {
if (s == null) {
return null;
}
if (s.length() == 0) {
return "";
}
StringBuilder buff = new StringBuilder(s.length());
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
switch (c) {
case '"':
buff.append("\\\"");
break;
case '\'':
buff.append("\\'");
break;
case '\\':
buff.append("\\\\");
break;
case '\n':
buff.append("\\n");
break;
case '\r':
buff.append("\\r");
break;
case '\t':
buff.append("\\t");
break;
default:
buff.append(c);
break;
}
}
return buff.toString();
}
}