package com.idega.util.resources;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PushbackInputStream;
import java.util.logging.Level;
import java.util.logging.Logger;
import com.idega.idegaweb.include.ExternalLink;
import com.idega.idegaweb.include.JavaScriptLink;
import com.idega.util.CoreConstants;
import com.idega.util.IOUtil;
import com.idega.util.StringHandler;
/**
*
* JSMin.java 2006-02-13
*
* Updated 2007-08-20 with updates from jsmin.c (2007-05-22)
*
* Copyright (c) 2006 John Reilly (www.inconspicuous.org)
*
* This work is a translation from C to Java of jsmin.c published by
* Douglas Crockford. Permission is hereby granted to use the Java
* version under the same conditions as the jsmin.c on which it is
* based.
*
*
*
*
* jsmin.c 2003-04-21
*
* Copyright (c) 2002 Douglas Crockford (www.crockford.com)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* The Software shall be used for Good, not Evil.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
**/
public class JavaScriptMinifier implements AbstractMinifier {
private static final int EOF = -1;
private PushbackInputStream in;
private OutputStream out;
private int theA;
private int theB;
public JavaScriptMinifier() {}
public JavaScriptMinifier(InputStream in, OutputStream out) {
this();
this.in = new PushbackInputStream(in);
this.out = out;
}
/**
* isAlphanum -- return true if the character is a letter, digit,
* underscore, dollar sign, or non-ASCII character.
*/
static boolean isAlphanum(int c) {
return ( (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') ||
(c >= 'A' && c <= 'Z') || c == '_' || c == '$' || c == '\\' ||
c > 126);
}
/**
* get -- return the next character from stdin. Watch out for lookahead. If
* the character is a control character, translate it to a space or
* linefeed.
*/
int get() throws IOException {
int c = in.read();
if (c >= ' ' || c == '\n' || c == EOF) {
return c;
}
if (c == '\r') {
return '\n';
}
return ' ';
}
/**
* Get the next character without getting it.
*/
int peek() throws IOException {
int lookaheadChar = in.read();
in.unread(lookaheadChar);
return lookaheadChar;
}
/**
* next -- get the next character, excluding comments. peek() is used to see
* if a '/' is followed by a '/' or '*'.
*/
int next() throws IOException, UnterminatedCommentException {
int c = get();
if (c == '/') {
switch (peek()) {
case '/':
for (;;) {
c = get();
if (c <= '\n') {
return c;
}
}
case '*':
get();
for (;;) {
switch (get()) {
case '*':
if (peek() == '/') {
get();
return ' ';
}
break;
case EOF:
throw new UnterminatedCommentException();
}
}
default:
return c;
}
}
return c;
}
/**
* action -- do something! What you do is determined by the argument: 1
* Output A. Copy B to A. Get the next B. 2 Copy B to A. Get the next B.
* (Delete A). 3 Get the next B. (Delete B). action treats a string as a
* single character. Wow! action recognizes a regular expression if it is
* preceded by ( or , or =.
*/
@SuppressWarnings("fallthrough")
void action(int d) throws IOException, UnterminatedRegExpLiteralException,
UnterminatedCommentException, UnterminatedStringLiteralException {
switch (d) {
case 1:
out.write(theA);
case 2:
theA = theB;
if (theA == '\'' || theA == '"') {
for (;;) {
out.write(theA);
theA = get();
if (theA == theB) {
break;
}
if (theA <= '\n') {
throw new UnterminatedStringLiteralException();
}
if (theA == '\\') {
out.write(theA);
theA = get();
}
}
}
case 3:
theB = next();
if (theB == '/' && (theA == '(' || theA == ',' || theA == '=' ||
theA == ':' || theA == '[' || theA == '!' ||
theA == '&' || theA == '|' || theA == '?' ||
theA == '{' || theA == '}' || theA == ';' ||
theA == '\n')) {
out.write(theA);
out.write(theB);
for (;;) {
theA = get();
if (theA == '/') {
break;
} else if (theA == '\\') {
out.write(theA);
theA = get();
} else if (theA <= '\n') {
throw new UnterminatedRegExpLiteralException();
}
out.write(theA);
}
theB = next();
}
}
}
/**
* jsmin -- Copy the input to the output, deleting the characters which are
* insignificant to JavaScript. Comments will be removed. Tabs will be
* replaced with spaces. Carriage returns will be replaced with linefeeds.
* Most spaces and linefeeds will be removed.
*/
private void jsmin() throws IOException, UnterminatedRegExpLiteralException, UnterminatedCommentException, UnterminatedStringLiteralException{
theA = '\n';
action(3);
while (theA != EOF) {
switch (theA) {
case ' ':
if (isAlphanum(theB)) {
action(1);
} else {
action(2);
}
break;
case '\n':
switch (theB) {
case '{':
case '[':
case '(':
case '+':
case '-':
action(1);
break;
case ' ':
action(3);
break;
default:
if (isAlphanum(theB)) {
action(1);
} else {
action(2);
}
}
break;
default:
switch (theB) {
case ' ':
if (isAlphanum(theA)) {
action(1);
break;
}
action(3);
break;
case '\n':
switch (theA) {
case '}':
case ']':
case ')':
case '+':
case '-':
case '"':
case '\'':
action(1);
break;
default:
if (isAlphanum(theA)) {
action(1);
} else {
action(3);
}
}
break;
default:
action(1);
break;
}
}
}
out.flush();
}
class UnterminatedCommentException extends Exception {
private static final long serialVersionUID = -2371646387982298945L;
}
class UnterminatedStringLiteralException extends Exception {
private static final long serialVersionUID = -3951474297141479527L;
}
class UnterminatedRegExpLiteralException extends Exception {
private static final long serialVersionUID = 5421327280143948956L;
}
public String getMinifiedResource(ExternalLink resource) {
if (!(resource instanceof JavaScriptLink)) {
Logger.getLogger(getClass().getName()).warning("Resource " + resource + " is not type of " + JavaScriptLink.class);
return null;
}
InputStream stream = resource.getContentStream();
if (stream == null) {
try {
stream = StringHandler.getStreamFromString(resource.getContent());
} catch (Exception e) {
e.printStackTrace();
}
}
if (stream == null) {
return null;
}
OutputStream output = null;
try {
output = new ByteArrayOutputStream();
this.in = new PushbackInputStream(stream);
this.out = output;
jsmin();
} catch(Exception e) {
output = null;
Logger.getLogger(JavaScriptMinifier.class.getName()).log(Level.WARNING, "Error while minifying resource", e);
} finally {
IOUtil.closeInputStream(this.in);
IOUtil.closeOutputStream(this.out);
}
if (output == null)
return null;
String script = output.toString();
if (!isValidScript((JavaScriptLink) resource, script)) {
script = getRestoredScript((JavaScriptLink) resource);
if (script == null) {
return null;
}
}
StringBuilder minified = new StringBuilder("\n/***************** STARTS: ").append(resource.getUrl()).append(" *****************/\n");
script = script.trim();
if (script.startsWith("(function")) {
script = CoreConstants.SEMICOLON.concat(script);
}
return minified.append(script).append("\n/***************** ENDS: ").append(resource.getUrl()).append(" *****************/\n").toString();
}
private boolean isValidScript(JavaScriptLink resource, String script) {
if (script == null) {
Logger.getLogger(JavaScriptMinifier.class.getName()).warning("Script is not valid: " + resource.getUrl());
return false;
}
return true;
}
private String getRestoredScript(JavaScriptLink resource) {
String script = resource.getContent();
if (script != null) {
return script;
}
try {
return StringHandler.getContentFromInputStream(resource.getContentStream());
} catch(Exception e) {
Logger.getLogger(JavaScriptMinifier.class.getName()).log(Level.WARNING, "Error while trying to get original script for: " + resource.getUrl(), e);
}
return null;
}
}