JavaScriptCompressorDirective.java
/*
* Copyright 2009-2022 the original author or authors.
*
* 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.googlecode.htmlcompressor.velocity;
import com.google.javascript.jscomp.CompilationLevel;
import com.googlecode.htmlcompressor.compressor.ClosureJavaScriptCompressor;
import com.googlecode.htmlcompressor.compressor.HtmlCompressor;
import com.googlecode.htmlcompressor.compressor.YuiJavaScriptCompressor;
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import org.apache.velocity.context.InternalContextAdapter;
import org.apache.velocity.exception.MethodInvocationException;
import org.apache.velocity.exception.TemplateInitException;
import org.apache.velocity.runtime.RuntimeServices;
import org.apache.velocity.runtime.directive.Directive;
import org.apache.velocity.runtime.parser.node.Node;
/**
* Velocity directive that compresses an JavaScript content within #compressJs ... #end block. All JavaScript-related
* properties from {@link HtmlCompressor} are supported.
*
* @author <a href="mailto:serg472@gmail.com">Sergiy Kovalchuk</a>
*
* @see HtmlCompressor
* @see <a href="http://developer.yahoo.com/yui/compressor/">Yahoo YUI Compressor</a>
* @see <a href="http://code.google.com/closure/compiler/">Google Closure Compiler</a>
*/
public class JavaScriptCompressorDirective extends Directive {
/** The enabled. */
private boolean enabled = true;
/** The js compressor. */
private String jsCompressor = HtmlCompressor.JS_COMPRESSOR_YUI;
// YUICompressor settings
/** The yui js no munge. */
private boolean yuiJsNoMunge;
/** The yui js preserve all semi colons. */
private boolean yuiJsPreserveAllSemiColons;
/** The yui js disable optimizations. */
private boolean yuiJsDisableOptimizations;
/** The yui js line break. */
private int yuiJsLineBreak = -1;
// Closure compressor settings
/** The closure opt level. */
private String closureOptLevel = ClosureJavaScriptCompressor.COMPILATION_LEVEL_SIMPLE;
@Override
public String getName() {
return "compressJs";
}
@Override
public int getType() {
return BLOCK;
}
@Override
public void init(RuntimeServices rs, InternalContextAdapter context, Node node) throws TemplateInitException {
super.init(rs, context, node);
log = rs.getLog();
// set compressor properties
enabled = rs.getBoolean("userdirective.compressJs.enabled", true);
jsCompressor = rs.getString("userdirective.compressHtml.jsCompressor", HtmlCompressor.JS_COMPRESSOR_YUI);
yuiJsNoMunge = rs.getBoolean("userdirective.compressJs.yuiJsNoMunge", false);
yuiJsPreserveAllSemiColons = rs.getBoolean("userdirective.compressJs.yuiJsPreserveAllSemiColons", false);
yuiJsLineBreak = rs.getInt("userdirective.compressJs.yuiJsLineBreak", -1);
closureOptLevel = rs.getString("userdirective.compressHtml.closureOptLevel",
ClosureJavaScriptCompressor.COMPILATION_LEVEL_SIMPLE);
}
@Override
public boolean render(InternalContextAdapter context, Writer writer, Node node)
throws IOException, MethodInvocationException {
// render content
StringWriter content = new StringWriter();
node.jjtGetChild(0).render(context, content);
// compress
if (enabled) {
try {
String result = content.toString();
if (jsCompressor.equalsIgnoreCase(HtmlCompressor.JS_COMPRESSOR_CLOSURE)) {
// call Closure compressor
ClosureJavaScriptCompressor closureCompressor = new ClosureJavaScriptCompressor();
if (closureOptLevel.equalsIgnoreCase(ClosureJavaScriptCompressor.COMPILATION_LEVEL_ADVANCED)) {
closureCompressor.setCompilationLevel(CompilationLevel.ADVANCED_OPTIMIZATIONS);
} else if (closureOptLevel
.equalsIgnoreCase(ClosureJavaScriptCompressor.COMPILATION_LEVEL_WHITESPACE)) {
closureCompressor.setCompilationLevel(CompilationLevel.WHITESPACE_ONLY);
} else {
closureCompressor.setCompilationLevel(CompilationLevel.SIMPLE_OPTIMIZATIONS);
}
result = closureCompressor.compress(result);
} else {
// call YUICompressor
YuiJavaScriptCompressor yuiCompressor = new YuiJavaScriptCompressor();
yuiCompressor.setDisableOptimizations(yuiJsDisableOptimizations);
yuiCompressor.setLineBreak(yuiJsLineBreak);
yuiCompressor.setNoMunge(yuiJsNoMunge);
yuiCompressor.setPreserveAllSemiColons(yuiJsPreserveAllSemiColons);
result = yuiCompressor.compress(result);
}
writer.write(result);
} catch (Exception e) {
writer.write(content.toString());
String msg = "Failed to compress content: " + content.toString();
log.error(msg, e);
throw new RuntimeException(msg, e);
}
} else {
writer.write(content.toString());
}
return true;
}
}