/*
* 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 com.asual.lesscss;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.mozilla.javascript.Context;
import org.mozilla.javascript.Function;
import org.mozilla.javascript.JavaScriptException;
import org.mozilla.javascript.NativeArray;
import org.mozilla.javascript.Scriptable;
import org.mozilla.javascript.ScriptableObject;
import org.mozilla.javascript.UniqueTag;
import org.mozilla.javascript.tools.shell.Global;
import com.asual.lesscss.loader.ChainedResourceLoader;
import com.asual.lesscss.loader.ClasspathResourceLoader;
import com.asual.lesscss.loader.CssProcessingResourceLoader;
import com.asual.lesscss.loader.FilesystemResourceLoader;
import com.asual.lesscss.loader.HTTPResourceLoader;
import com.asual.lesscss.loader.JNDIResourceLoader;
import com.asual.lesscss.loader.ResourceLoader;
import com.asual.lesscss.loader.UnixNewlinesResourceLoader;
/**
* @author Rostislav Hristov
* @author Uriah Carpenter
* @author Noah Sloan
*/
public class LessEngine {
private static LessEngine instance;
private final Log logger = LogFactory.getLog(getClass());
private final LessOptions options;
private final ResourceLoader loader;
private Scriptable scope;
private Function compile;
public static synchronized LessEngine getInstance() {
if (instance == null)
instance = new LessEngine();
return instance;
}
public LessEngine() {
this(new LessOptions());
}
public LessEngine(LessOptions options) {
this(options, defaultResourceLoader(options));
}
private static ResourceLoader defaultResourceLoader(LessOptions options) {
ResourceLoader resourceLoader = new ChainedResourceLoader(
new FilesystemResourceLoader(), new ClasspathResourceLoader(
LessEngine.class.getClassLoader()),
new JNDIResourceLoader(), new HTTPResourceLoader());
if (options.isCss()) {
return new CssProcessingResourceLoader(resourceLoader);
}
resourceLoader = new UnixNewlinesResourceLoader(resourceLoader);
return resourceLoader;
}
/**
*
* @param options
* @param loader
* @see <a href="http://www.envjs.com/doc/guides#running-embed">Embedding EnvJS</a>
*/
public LessEngine(LessOptions options, ResourceLoader loader) {
this.options = options;
this.loader = loader;
try {
logger.debug("Initializing LESS Engine.");
ClassLoader classLoader = getClass().getClassLoader();
URL less = options.getLess();
URL env = classLoader.getResource("META-INF/env.js");
URL engine = classLoader.getResource("META-INF/engine.js");
URL cssmin = classLoader.getResource("META-INF/cssmin.js");
Context cx = Context.enter();
logger.debug("Using implementation version: "
+ cx.getImplementationVersion());
cx.setOptimizationLevel(-1);
Global global = new Global();
global.init(cx);
scope = cx.initStandardObjects(global);
cx.evaluateReader(scope, new InputStreamReader(env.openConnection()
.getInputStream()), env.getFile(), 1, null);
Scriptable lessEnv = (Scriptable) scope.get("lessenv", scope);
lessEnv.put("charset", lessEnv, options.getCharset());
lessEnv.put("css", lessEnv, options.isCss());
lessEnv.put("lineNumbers", lessEnv, options.getLineNumbers());
lessEnv.put("optimization", lessEnv, options.getOptimization());
lessEnv.put("loader", lessEnv, Context.javaToJS(loader, scope));
cx.evaluateReader(scope, new InputStreamReader(less
.openConnection().getInputStream()), less.getFile(), 1,
null);
cx.evaluateReader(scope, new InputStreamReader(cssmin
.openConnection().getInputStream()), cssmin.getFile(), 1,
null);
cx.evaluateReader(scope, new InputStreamReader(engine
.openConnection().getInputStream()), engine.getFile(), 1,
null);
compile = (Function) scope.get("compile", scope);
Context.exit();
} catch (Exception e) {
logger.error("LESS Engine intialization failed.", e);
}
}
public String compile(String input) throws LessException {
return compile(input, null, false);
}
public String compile(String input, String location) throws LessException {
return compile(input, location, false);
}
public String compile(String input, String location, boolean compress)
throws LessException {
try {
long time = System.currentTimeMillis();
String result = call(compile, new Object[] { input,
location == null ? "" : location, compress });
logger.debug("The compilation of '" + input + "' took "
+ (System.currentTimeMillis() - time) + " ms.");
return result;
} catch (Exception e) {
throw parseLessException(e);
}
}
public String compile(URL input) throws LessException {
return compile(input, false);
}
public String compile(URL input, boolean compress) throws LessException {
try {
long time = System.currentTimeMillis();
String location = input.toString();
logger.debug("Compiling URL: " + location);
String source = loader.load(location, options.getCharset());
String result = call(compile, new Object[] { source, location,
compress });
logger.debug("The compilation of '" + input + "' took "
+ (System.currentTimeMillis() - time) + " ms.");
return result;
} catch (Exception e) {
throw parseLessException(e);
}
}
public String compile(File input) throws LessException {
return compile(input, false);
}
public String compile(File input, boolean compress) throws LessException {
try {
long time = System.currentTimeMillis();
String location = input.getAbsolutePath();
logger.debug("Compiling File: " + "file:" + location);
String source = loader.load(location, options.getCharset());
String result = call(compile, new Object[] { source, location,
compress });
logger.debug("The compilation of '" + input + "' took "
+ (System.currentTimeMillis() - time) + " ms.");
return result;
} catch (Exception e) {
throw parseLessException(e);
}
}
public void compile(File input, File output) throws LessException,
IOException {
compile(input, output, false);
}
public void compile(File input, File output, boolean compress)
throws LessException, IOException {
try {
String content = compile(input, compress);
if (!output.exists()) {
output.createNewFile();
}
BufferedWriter bw = new BufferedWriter(new FileWriter(output));
bw.write(content);
bw.close();
} catch (Exception e) {
throw parseLessException(e);
}
}
private String call(Function fn, Object[] args) {
return (String) Context.call(null, fn, scope, scope, args);
}
private boolean hasProperty(Scriptable value, String name) {
Object property = ScriptableObject.getProperty(value, name);
return property != null && !property.equals(UniqueTag.NOT_FOUND);
}
private LessException parseLessException(Exception root)
throws LessException {
logger.debug("Parsing LESS Exception", root);
if (root instanceof JavaScriptException) {
Scriptable value = (Scriptable) ((JavaScriptException) root)
.getValue();
String type = ScriptableObject.getProperty(value, "type")
.toString() + " Error";
String message = ScriptableObject.getProperty(value, "message")
.toString();
String filename = "";
if (hasProperty(value, "filename")) {
filename = ScriptableObject.getProperty(value, "filename")
.toString();
}
int line = -1;
if (hasProperty(value, "line")) {
line = ((Double) ScriptableObject.getProperty(value, "line"))
.intValue();
}
int column = -1;
if (hasProperty(value, "column")) {
column = ((Double) ScriptableObject
.getProperty(value, "column")).intValue();
}
List<String> extractList = new ArrayList<String>();
if (hasProperty(value, "extract")) {
NativeArray extract = (NativeArray) ScriptableObject
.getProperty(value, "extract");
for (int i = 0; i < extract.getLength(); i++) {
if (extract.get(i, extract) instanceof String) {
extractList.add(((String) extract.get(i, extract))
.replace("\t", " "));
}
}
}
throw new LessException(message, type, filename, line, column,
extractList);
}
throw new LessException(root);
}
}