AdaptiveTemplate.java

/*
 * Copyright 2011-2013 HTTL Team.
 *  
 * 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 httl.spi.translators.templates;

import httl.*;
import httl.spi.Converter;

import java.io.*;
import java.text.ParseException;
import java.util.*;

/**
 * Adaptive Template. (SPI, Prototype, ThreadSafe)
 *
 * @author Liang Fei (liangfei0201 AT gmail DOT com)
 * @see httl.Engine#getTemplate(String)
 */
public class AdaptiveTemplate implements Template, Serializable {

    private static final long serialVersionUID = 3094907176375413567L;

    private final Template writerTemplate;

    private final Template streamTemplate;

    private final Converter<Object, Object> outConverter;
    private Map<String, Template> macros;

    public AdaptiveTemplate(Template writerTemplate, Template streamTemplate, Converter<Object, Object> outConverter) {
        if (writerTemplate == null)
            throw new IllegalArgumentException("writer template == null");
        if (streamTemplate == null)
            throw new IllegalArgumentException("stream template == null");
        this.writerTemplate = writerTemplate;
        this.streamTemplate = streamTemplate;
        this.outConverter = outConverter;
    }

    public String getName() {
        return writerTemplate.getName();
    }

    public String getEncoding() {
        return writerTemplate.getEncoding();
    }

    public Locale getLocale() {
        return writerTemplate.getLocale();
    }

    public long getLastModified() {
        return writerTemplate.getLastModified();
    }

    public long getLength() {
        return writerTemplate.getLength();
    }

    public String getSource() throws IOException {
        return writerTemplate.getSource();
    }

    public Reader openReader() throws IOException {
        return writerTemplate.openReader();
    }

    public InputStream openStream() throws IOException {
        return streamTemplate.openStream();
    }

    public Engine getEngine() {
        return writerTemplate.getEngine();
    }

    public Object evaluate() throws ParseException {
        // Context.getOut() only OutputStream or Writer
        if (Context.getContext().getOut() instanceof OutputStream) {
            return streamTemplate.evaluate();
        } else {
            return writerTemplate.evaluate();
        }
    }

    public Object evaluate(Object context) throws ParseException {
        // Context.getOut() only OutputStream or Writer
        if (Context.getContext().getOut() instanceof OutputStream) {
            return streamTemplate.evaluate(context);
        } else {
            return writerTemplate.evaluate(context);
        }
    }

    public void render() throws IOException, ParseException {
        render(Context.getContext().getOut());
    }

    public void render(Object out) throws IOException, ParseException {
        if (out instanceof OutputStream) {
            streamTemplate.render(out);
        } else if (out instanceof Writer) {
            writerTemplate.render(out);
        } else {
            out = outConverter.convert(out, getVariables());
            if (out instanceof OutputStream) {
                streamTemplate.render(out);
            } else {
                writerTemplate.render(out);
            }
        }
    }

    public void render(Object context, Object out)
            throws IOException, ParseException {
        if (out instanceof OutputStream) {
            streamTemplate.render(context, out);
        } else if (out instanceof Writer) {
            writerTemplate.render(context, out);
        } else {
            out = outConverter.convert(out, getVariables());
            if (out instanceof OutputStream) {
                streamTemplate.render(context, out);
            } else {
                writerTemplate.render(context, out);
            }
        }
    }

    public Map<String, Class<?>> getVariables() {
        return writerTemplate.getVariables();
    }

    public Map<String, Template> getMacros() {
        if (macros == null) { // allow duplicate on concurrent
            Map<String, Template> map = new HashMap<String, Template>();
            Map<String, Template> writerMacros = writerTemplate.getMacros();
            Map<String, Template> streamMacros = streamTemplate.getMacros();
            for (Map.Entry<String, Template> entry : writerMacros.entrySet()) {
                map.put(entry.getKey(), new AdaptiveTemplate(entry.getValue(), streamMacros.get(entry.getKey()), outConverter));
            }
            macros = Collections.unmodifiableMap(map);
        }
        return macros;
    }

    public int getOffset() {
        return writerTemplate.getOffset();
    }

    public boolean isMacro() {
        return writerTemplate.isMacro();
    }

    public void accept(Visitor visitor) throws IOException, ParseException {
        writerTemplate.accept(visitor);
    }

    public Template getParent() {
        return writerTemplate.getParent();
    }

    public List<Node> getChildren() {
        return writerTemplate.getChildren();
    }

    @Override
    public String toString() {
        return writerTemplate.toString();
    }

}