package com.theoryinpractise.coffeescript;
import com.google.common.base.Charsets;
import com.google.common.collect.Lists;
import com.google.common.io.Files;
import com.google.javascript.jscomp.*;
import com.google.javascript.jscomp.Compiler;
import org.apache.maven.plugin.logging.Log;
import java.io.File;
import java.io.IOException;
import java.util.List;
/**
* Copyright 2011 Mark Derricutt.
*
* Contributing authors:
* Daniel Bower
*
* 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.
*
*
* Run the Closure Compiler tool on a directory of Javascripts.
*
* This class supports no configuration in its current form.
*
*/
public class ClosureMinifier {
public ClosureMinifier(Log logger){
this.logger = logger;
}
public ClosureMinifier(String compilationLevel, Log logger){
this.compilationLevel = compilationLevel;
this.logger = logger;
}
private Log logger;
private String compilationLevel = CompilationLevel.SIMPLE_OPTIMIZATIONS.toString();
public void compile(List<File> filesToCompile, String destFileName){
File destFile = prepareDestFile(destFileName);
Compiler compiler = new Compiler();
Result results = compiler.compile(getExterns(), getInputs(filesToCompile), getCompilerOptions());
logger.debug(results.debugLog);
for(JSError error : results.errors){
logger.error("Closure Minifier Error: " + error.sourceName + " Description: " + error.description);
}
for(JSError warning : results.warnings){
logger.info("Closure Minifier Warning: " + warning.sourceName + " Description: " + warning.description);
}
if (results.success) {
try {
Files.write(compiler.toSource(), destFile, Charsets.UTF_8);
} catch (IOException e) {
throw new ClosureException("Failed to write minified file to " + destFile, e);
}
}else{
throw new ClosureException("Closure Compiler Failed - See error messages on System.err");
}
}
/**
* Prepare the Destination File, Remove if it already exists
* @param destFileName
*/
private File prepareDestFile(String destFileName){
File destFile = new File(destFileName);
if(destFile.exists()){
destFile.delete();
}
return destFile;
}
/**
* Prepare options for the Compiler.
*/
private CompilerOptions getCompilerOptions(){
CompilationLevel level = null;
try {
level = CompilationLevel.valueOf(this.compilationLevel);
} catch (IllegalArgumentException e) {
throw new ClosureException("Compilation level is invalid", e);
}
CompilerOptions options = new CompilerOptions();
level.setOptionsForCompilationLevel(options);
return options;
}
/**
* Externs are defined in the Closure documentations as:
* External variables are declared in 'externs' files. For instance, the file may include
* definitions for global javascript/browser objects such as window, document.
*
* This method sneaks into the CommandLineRunner class of the Closure command line tool
* and pulls the default Externs there. This class could be modified to instead look
* somewhere more relevant to the project.
*/
private JSSourceFile[] getExterns(){
List<JSSourceFile> externs = Lists.newArrayList();
try {
externs = CommandLineRunner.getDefaultExterns();
} catch (IOException e) {
throw new ClosureException("Unable to load default External variables Files. The files include definitions for global javascript/browser objects such as window, document.", e);
}
return externs.toArray(new JSSourceFile[externs.size()]);
}
private JSSourceFile[] getInputs(List<File> filesToProcess){
List<JSSourceFile> files = Lists.newArrayList();
for(File file : filesToProcess){
files.add(JSSourceFile.fromFile(file));
}
return files.toArray(new JSSourceFile[files.size()]);
}
public String getCompilationLevel() {
return compilationLevel;
}
public void setCompilationLevel(String compilationLevel) {
this.compilationLevel = compilationLevel;
}
}