//TemplateEngine.java
//-------------------------------------
//(C) by Michael Peter Christen; mc@yacy.net
//first published on http://www.anomic.de
//Frankfurt, Germany, 2004
//last major change: 16.01.2005
//$LastChangedDate: 2011-06-26 23:15:13 +0200 (So, 26. Jun 2011) $
//$LastChangedRevision: 7800 $
//$LastChangedBy: orbiter $
//extended for multi- and alternatives-templates by Alexander Schier
//This program is free software; you can redistribute it and/or modify
//it under the terms of the GNU General Public License as published by
//the Free Software Foundation; either version 2 of the License, or
//(at your option) any later version.
//This program 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 General Public License for more details.
//You should have received a copy of the GNU General Public License
//along with this program; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//Using this software in any meaning (reading, learning, copying, compiling,
//running) means that you agree that the Author(s) is (are) not responsible
//for cost, loss of data or any harm that may be caused directly or indirectly
//by usage of this softare or this documentation. The usage of this software
//is on your own risk. The installation and usage (starting/running) of this
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//the software.
//Any changes to this file according to the GPL as documented in the file
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package de.anomic.http.server;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PushbackInputStream;
import java.util.HashMap;
import java.util.Map;
import net.yacy.cora.document.ASCII;
import net.yacy.cora.document.UTF8;
import net.yacy.kelondro.logging.Log;
import net.yacy.kelondro.util.ByteBuffer;
import net.yacy.kelondro.util.FileUtils;
/**
* A template engine, which substitutes patterns in strings<br>
*
* The template engine supports four types of templates:<br>
* <ol>
* <li>Normal templates: the template will be replaced by a string.</li>
* <li>Multi templates: the template will be used more than one time.<br>
* i.e. for lists</li>
* <li>3. Alternatives: the program chooses one of multiple alternatives.</li>
* <li>Includes: another file with templates will be included.</li>
* </ol>
*
* All these templates can be used recursivly.<p>
* <b>HTML-Example</b><br>
* <pre>
* <html><head></head><body>
* #{times}#
* Good #(daytime)#morning::evening#(/daytime)#, #[name]#!(#[num]#. Greeting)<br>
* #{/times}#
* </body></html>
* </pre>
* <p>
* The corresponding Hashtable to use this Template:<br>
* <b>Java Example</b><br>
* <pre>
* Hashtable pattern;
* pattern.put("times", 10); //10 greetings
* for(int i=0;i<=9;i++){
* pattern.put("times_"+i+"_daytime", 1); //index: 1, second Entry, evening
* pattern.put("times_"+i+"_name", "John Connor");
* pattern.put("times_"+i+"_num", (i+1));
* }
* </pre>
* <p>
* <b>Recursion</b><br>
* If you use recursive templates, the templates will be used from
* the external to the internal templates.
* In our Example, the Template in #{times}##{/times}# will be repeated ten times.<br>
* Then the inner Templates will be applied.
* <p>
* The inner templates have a prefix, so they may have the same name as a template on another level,
* or templates which are in another recursive template.<br>
* <b>The Prefixes:</b>
* <ul>
* <li>Multi templates: multitemplatename_index_</li>
* <li>Alterantives: alternativename_</li>
* </ul>
* So the Names in the Hashtable are:
* <ul>
* <li>Multi templates: multitemplatename_index_templatename</li>
* <li>Alterantives: alternativename_templatename</li>
* </ul>
* <i>#(alternative)#::#{repeat}##[test]##{/repeat}##(/alternative)#</i><br>
* would be adressed as "alternative_repeat_"+number+"_test"
*/
public final class TemplateEngine {
public final static byte hashChar = (byte)'#';
public final static byte[] slashChar = {(byte)'/'};
public final static byte pcChar = (byte)'%';
public final static byte[] dpdpa = "::".getBytes();
public final static byte lbr = (byte)'[';
public final static byte rbr = (byte)']';
public final static byte[] pOpen = {hashChar, lbr};
public final static byte[] pClose = {rbr, hashChar};
public final static byte lcbr = (byte)'{';
public final static byte rcbr = (byte)'}';
public final static byte[] mOpen = {hashChar, lcbr};
public final static byte[] mClose = {rcbr, hashChar};
public final static byte lrbr = (byte)'(';
public final static byte rrbr = (byte)')';
public final static byte[] aOpen = {hashChar, lrbr};
public final static byte[] aClose = {rrbr, hashChar};
public final static byte[] iOpen = {hashChar, pcChar};
public final static byte[] iClose = {pcChar, hashChar};
public final static byte[] ul = "_".getBytes();
private final static byte[] alternative_which = ASCII.getBytes(" type=\"alternative\" which=\"");
private final static byte[] multi_num = ASCII.getBytes(" type=\"multi\" num=\"");
private final static byte[] open_endtag = ASCII.getBytes("</");
private final static byte[] close_quotetagn = ASCII.getBytes("\">\n");
private final static byte[] close_tagn = ASCII.getBytes(">\n");
private final static byte[] PP = ASCII.getBytes("%%");
private final static byte[] hash_brackopen_slash = ASCII.getBytes("#(/");
private final static byte[] brackclose_hash = ASCII.getBytes(")#");
/**
* transfer until a specified pattern is found; everything but the pattern is transfered so far
* the function returns true, if the pattern is found
*/
private final static boolean transferUntil(final PushbackInputStream i, final OutputStream o, final byte[] pattern) throws IOException {
int b, bb;
boolean equal;
while ((b = i.read()) > 0) {
if ((b & 0xFF) == pattern[0]) {
// read the whole pattern
equal = true;
lo: for (int n = 1; n < pattern.length; n++) {
if (((bb = i.read()) & 0xFF) != pattern[n]) {
// push back all
i.unread(bb);
equal = false;
for (int nn = n - 1; nn > 0; nn--) i.unread(pattern[nn]);
break lo;
}
}
if (equal) return true;
}
o.write(b);
}
return false;
}
private final static boolean transferUntil(final PushbackInputStream i, final OutputStream o, final byte p) throws IOException {
int b;
while ((b = i.read()) > 0) {
if ((b & 0xFF) == p) return true;
o.write(b);
}
return false;
}
public final static void writeTemplate(final InputStream in, final OutputStream out, final Map<String, String> pattern, final byte[] dflt) throws IOException {
if (pattern == null) {
FileUtils.copy(in, out);
} else {
writeTemplate(in, out, pattern, dflt, new byte[0]);
}
}
/**
* Reads a input stream, and writes the data with replaced templates on a output stream
*/
private final static byte[] writeTemplate(final InputStream in, final OutputStream out, final Map<String, String> pattern, final byte[] dflt, final byte[] prefix) throws IOException {
final PushbackInputStream pis = new PushbackInputStream(in, 100);
final ByteArrayOutputStream keyStream = new ByteArrayOutputStream(512);
byte[] key;
byte[] multi_key;
byte[] replacement;
int bb;
final ByteBuffer structure = new ByteBuffer();
while (transferUntil(pis, out, hashChar)) {
bb = pis.read();
keyStream.reset();
// #{
if ((bb & 0xFF) == lcbr) { //multi
if (transferUntil(pis, keyStream, mClose)) { //close tag
//multi_key = "_" + keyStream.toString(); //for _Key
bb = pis.read();
if ((bb & 0xFF) != 10){ //kill newline
pis.unread(bb);
}
multi_key = keyStream.toByteArray(); //IMPORTANT: no prefix here
keyStream.reset(); //reset stream
//this needs multi_key without prefix
if (transferUntil(pis, keyStream, appendBytes(mOpen, slashChar, multi_key, mClose))){
bb = pis.read();
if((bb & 0xFF) != 10){ //kill newline
pis.unread(bb);
}
final byte[] text=keyStream.toByteArray(); //text between #{key}# an #{/key}#
int num=0;
final String patternKey = getPatternKey(prefix, multi_key);
if(pattern.containsKey(patternKey) && pattern.get(patternKey) != null){
try{
num=Integer.parseInt(pattern.get(patternKey)); // Key contains the iteration number as string
}catch(final NumberFormatException e){
num=0;
}
}
structure.append('<')
.append(multi_key)
.append(multi_num)
.append(ASCII.getBytes(Integer.toString(num)))
.append(close_quotetagn);
for(int i=0;i < num;i++) {
final PushbackInputStream pis2 = new PushbackInputStream(new ByteArrayInputStream(text));
//System.out.println("recursing with text(prefix="+ multi_key + "_" + i + "_" +"):"); //DEBUG
//System.out.println(text);
structure.append(writeTemplate(pis2, out, pattern, dflt, newPrefix(prefix,multi_key,i)));
}//for
structure.append(open_endtag).append(multi_key).append(close_tagn);
} else {//transferUntil
Log.logSevere("TEMPLATE", "No Close Key found for #{"+UTF8.String(multi_key)+"}#"); //prefix here?
}
}
// #(
} else if ((bb & 0xFF) == lrbr) { //alternative
int others=0;
final ByteBuffer text= new ByteBuffer();
transferUntil(pis, keyStream, aClose);
key = keyStream.toByteArray(); //Caution: Key does not contain prefix
keyStream.reset(); //clear
boolean byName=false;
int whichPattern=0;
byte[] patternName = new byte[0];
final String patternKey = getPatternKey(prefix, key);
if(pattern.containsKey(patternKey) && pattern.get(patternKey) != null){
final String patternId=pattern.get(patternKey);
try{
whichPattern=Integer.parseInt(patternId); //index
}catch(final NumberFormatException e){
whichPattern=0;
byName=true;
patternName = UTF8.getBytes(patternId);
}
}
int currentPattern=0;
boolean found=false;
keyStream.reset(); //reset stream
PushbackInputStream pis2;
if (byName) {
//TODO: better Error Handling
transferUntil(pis, keyStream, appendBytes(PP, patternName, null, null));
if(pis.available()==0){
Log.logSevere("TEMPLATE", "No such Template: %%" + UTF8.String(patternName));
return structure.getBytes();
}
keyStream.reset();
transferUntil(pis, keyStream, dpdpa);
pis2 = new PushbackInputStream(new ByteArrayInputStream(keyStream.toByteArray()));
structure.append(writeTemplate(pis2, out, pattern, dflt, newPrefix(prefix,key)));
transferUntil(pis, keyStream, appendBytes(hash_brackopen_slash, key, brackclose_hash, null));
if(pis.available()==0){
Log.logSevere("TEMPLATE", "No Close Key found for #("+UTF8.String(key)+")# (by Name)");
}
} else {
while(!found){
bb=pis.read(); // performance problem? trace always points to this line
if ((bb & 0xFF) == hashChar){
bb=pis.read();
if ((bb & 0xFF) == lrbr){
transferUntil(pis, keyStream, aClose);
//reached the end. output last string.
if (java.util.Arrays.equals(keyStream.toByteArray(),appendBytes(slashChar, key, null,null))) {
pis2 = new PushbackInputStream(new ByteArrayInputStream(text.getBytes()));
//this maybe the wrong, but its the last
structure.append('<').append(key).append(alternative_which).append(ASCII.getBytes(Integer.toString(whichPattern))).append(ASCII.getBytes("\" found=\"0\">\n"));
structure.append(writeTemplate(pis2, out, pattern, dflt, newPrefix(prefix,key)));
structure.append(open_endtag).append(key).append(close_tagn);
found=true;
}else if(others >0 && keyStream.toString().startsWith("/")){ //close nested
others--;
text.append(aOpen).append(keyStream.toByteArray()).append(brackclose_hash);
} else { //nested
others++;
text.append(aOpen).append(keyStream.toByteArray()).append(brackclose_hash);
}
keyStream.reset(); //reset stream
continue;
} //is not #(
pis.unread(bb);//is processed in next loop
bb = (hashChar);//will be added to text this loop
//text += "#";
}else if ((bb & 0xFF) == ':' && others==0){//ignore :: in nested Expressions
bb=pis.read();
if ((bb & 0xFF) == ':'){
if(currentPattern == whichPattern){ //found the pattern
pis2 = new PushbackInputStream(new ByteArrayInputStream(text.getBytes()));
structure.append('<').append(key).append(alternative_which).append(ASCII.getBytes(Integer.toString(whichPattern))).append(ASCII.getBytes("\" found=\"0\">\n"));
structure.append(writeTemplate(pis2, out, pattern, dflt, newPrefix(prefix,key)));
structure.append(open_endtag).append(key).append(close_tagn);
transferUntil(pis, keyStream, appendBytes(hash_brackopen_slash, key, brackclose_hash,null));//to #(/key)#.
found=true;
}
currentPattern++;
text.clear();
continue;
}
text.append(':');
}
if(!found){
text.append((byte)bb);/*
if(pis.available()==0){
serverLog.logSevere("TEMPLATE", "No Close Key found for #("+UTF8.String(key)+")# (by Index)");
found=true;
}*/
}
}//while
}//if(byName) (else branch)
// #[
} else if ((bb & 0xFF) == lbr) { //normal
if (transferUntil(pis, keyStream, pClose)) {
// pattern detected, write replacement
key = keyStream.toByteArray();
final String patternKey = getPatternKey(prefix, key);
replacement = replacePattern(patternKey, pattern, dflt); //replace
structure.append('<').append(key)
.append(ASCII.getBytes(" type=\"normal\">\n"));
structure.append(replacement);
structure.append(ASCII.getBytes("</")).append(key)
.append(close_tagn);
FileUtils.copy(replacement, out);
} else {
// inconsistency, simply finalize this
FileUtils.copy(pis, out);
return structure.getBytes();
}
// #%
} else if ((bb & 0xFF) == pcChar) { //include
final ByteBuffer include = new ByteBuffer();
keyStream.reset(); //reset stream
if(transferUntil(pis, keyStream, iClose)){
byte[] filename = keyStream.toByteArray();
//if(filename.startsWith( Character.toString((char)lbr) ) && filename.endsWith( Character.toString((char)rbr) )){ //simple pattern for filename
if((filename[0] == lbr) && (filename[filename.length-1] == rbr)){ //simple pattern for filename
final byte[] newFilename = new byte[filename.length-2];
System.arraycopy(filename, 1, newFilename, 0, newFilename.length);
final String patternkey = getPatternKey(prefix, newFilename);
filename= replacePattern(patternkey, pattern, dflt);
}
if (filename.length > 0 && !java.util.Arrays.equals(filename, dflt)) {
BufferedReader br = null;
try{
//br = new BufferedReader(new InputStreamReader(new FileInputStream( filename ))); //Simple Include
br = new BufferedReader( new InputStreamReader(new FileInputStream( HTTPDFileHandler.getLocalizedFile(UTF8.String(filename))),"UTF-8") ); //YaCy (with Locales)
//Read the Include
String line = "";
while ((line = br.readLine()) != null) {
include.append(UTF8.getBytes(line)).append(ASCII.getBytes(de.anomic.server.serverCore.CRLF_STRING));
}
} catch (final IOException e) {
//file not found?
Log.logSevere("FILEHANDLER","Include Error with file " + UTF8.String(filename) + ": " + e.getMessage());
} finally {
if (br != null) try { br.close(); br=null; } catch (final Exception e) {}
}
final PushbackInputStream pis2 = new PushbackInputStream(new ByteArrayInputStream(include.getBytes()));
structure.append(ASCII.getBytes("<fileinclude file=\"")).append(filename).append(close_tagn);
structure.append(writeTemplate(pis2, out, pattern, dflt, prefix));
structure.append(ASCII.getBytes("</fileinclude>\n"));
}
}
// # - no special character. This is simply a '#' without meaning
} else { //no match, but a single hash (output # + bb)
out.write(hashChar);
out.write(bb);
}
}
return structure.getBytes();
}
private final static byte[] replacePattern(final String key, final Map<String, String> pattern, final byte dflt[]) {
byte[] replacement;
Object value;
if (pattern.containsKey(key)) {
value = pattern.get(key);
if (value instanceof byte[]) {
replacement = (byte[]) value;
} else if (value instanceof String) {
//replacement = ((String) value).getBytes();
replacement = UTF8.getBytes(((String) value));
} else {
//replacement = value.toString().getBytes();
replacement = UTF8.getBytes(value.toString());
}
} else {
replacement = dflt;
}
return replacement;
}
private final static byte[] newPrefix(final byte[] oldPrefix, final byte[] key) {
final ByteBuffer newPrefix = new ByteBuffer(oldPrefix.length + key.length + 1);
newPrefix.append(oldPrefix).append(key).append(ul);
final byte[] result = newPrefix.getBytes();
try {
newPrefix.close();
} catch (final IOException e) {
Log.logException(e);
}
return result;
}
private final static byte[] newPrefix(final byte[] oldPrefix, final byte[] multi_key, final int i) {
final ByteBuffer newPrefix = new ByteBuffer(oldPrefix.length + multi_key.length + 8);
newPrefix.append(oldPrefix).append(multi_key).append(ul).append(ASCII.getBytes(Integer.toString(i))).append(ul);
try {
newPrefix.close();
} catch (final IOException e) {
Log.logException(e);
}
return newPrefix.getBytes();
}
private final static String getPatternKey(final byte[] prefix, final byte[] key) {
final ByteBuffer patternKey = new ByteBuffer(prefix.length + key.length);
patternKey.append(prefix).append(key);
try {
return UTF8.String(patternKey.getBytes());
} finally {
try {
patternKey.close();
} catch (final IOException e) {
Log.logException(e);
}
}
}
private final static byte[] appendBytes(final byte[] b1, final byte[] b2, final byte[] b3, final byte[] b4) {
final ByteBuffer byteArray = new ByteBuffer(b1.length + b2.length + (b3 == null ? 0 : b3.length) + (b4 == null ? 0 : b4.length));
byteArray.append(b1).append(b2);
if (b3 != null) byteArray.append(b3);
if (b4 != null) byteArray.append(b4);
final byte[] result = byteArray.getBytes();
try {
byteArray.close();
} catch (final IOException e) {
Log.logException(e);
}
return result;
}
public static void main(final String[] args) {
// arg1 = test input; arg2 = replacement for pattern 'test'; arg3 = default replacement
try {
final InputStream i = new ByteArrayInputStream(UTF8.getBytes(args[0]));
final Map<String, String> h = new HashMap<String, String>();
h.put("test", args[1]);
writeTemplate(new PushbackInputStream(i, 100), System.out, h, UTF8.getBytes(args[2]));
System.out.flush();
} catch (final Exception e) {
Log.logException(e);
}
}
}