com.github.jknack.amd4j.Optimizer.java Source code

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Here is the source code for com.github.jknack.amd4j.Optimizer.java

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/**
 * Copyright (c) 2013 Edgar Espina
 *
 * This file is part of amd4j (https://github.com/jknack/amd4j)
 *
 * 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.github.jknack.amd4j;

import static org.apache.commons.lang3.Validate.notNull;

import java.io.PrintWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.io.IOUtils;

/**
 * Merge a module and module's dependencies into a single file.
 *
 * @author edgar.espina
 * @since 0.1.0
 */
public class Optimizer extends OncePerModuleVisitor<CharSequence> {

    /**
     * The configuration options.
     */
    private Config config;

    /**
     * The transformer set.
     */
    private List<Transformer> transformers = new ArrayList<Transformer>();

    /**
     * The writer.
     */
    private StringBuilder buffer;

    /**
     * Creates a new {@link Optimizer}.
     *
     * @param config The configuration options. Required.
     * @param transformers The list of additional transformer to use. Required.
     */
    public Optimizer(final Config config, final List<Transformer> transformers) {
        this.config = notNull(config, "The config is required.");
        notNull(transformers, "The transformers is required.");
        this.transformers.addAll(transformers);
        this.transformers.add(new SemicolonAppenderPlugin());
        this.transformers.add(new AmdTransformer());
    }

    @Override
    public CharSequence walk(final Module module) {
        buffer = new StringBuilder();
        PrintWriter writer = null;
        try {
            module.traverse(this);
            Writer out = config.getOut();
            Minifier minifier = config.getOptimize();
            CharSequence minified = minifier.minify(config, buffer);
            if (out != null) {
                writer = new PrintWriter(out);
                writer.append(minified);
            }
            return minified;
        } finally {
            IOUtils.closeQuietly(writer);
        }
    }

    @Override
    public void endvisit(final Module module) {
        StringBuilder content = new StringBuilder(module.content);
        for (Transformer transformer : transformers) {
            if (transformer.apply(module.uri)) {
                content = transformer.transform(config, module.name, content);
            }
        }
        buffer.append("\n").append(content);
    }
}