com.mitchellbosecke.pebble.spring4.PebbleView Maven / Gradle / Ivy

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/*******************************************************************************
 * Copyright (c) 2013 by Mitchell Bösecke
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 ******************************************************************************/
package com.mitchellbosecke.pebble.spring4;

import java.io.Writer;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Locale;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.servlet.support.RequestContextUtils;
import org.springframework.web.servlet.view.AbstractTemplateView;

import com.mitchellbosecke.pebble.PebbleEngine;
import com.mitchellbosecke.pebble.spring4.context.Beans;
import com.mitchellbosecke.pebble.template.PebbleTemplate;

public class PebbleView extends AbstractTemplateView {

    public static final String REQUEST_VARIABLE_NAME = "request";

    public static final String RESPONSE_VARIABLE_NAME = "response";

    public static final String SESSION_VARIABLE_NAME = "session";

    private static final String BEANS_VARIABLE_NAME = "beans";

    private static final int NANOS_IN_SECOND = 1000000;

    /**
     * 
     * TIMER logger. This logger will output the time required for executing
     * each template processing operation.
     * 
     * 
     * The value of this constant is
     * com.mitchellbosecke.pebble.spring.PebbleView.TIMER. This allows
     * you to set a specific configuration and/or appenders for timing info at
     * your logging system configuration.
     * 
     */
    private static final Logger TIMER_LOGGER = LoggerFactory.getLogger(PebbleView.class.getName() + ".timer");

    private String characterEncoding = "UTF-8";

    private PebbleEngine engine;

    private String templateName;

    public void setCharacterEncoding(String characterEncoding) {
        this.characterEncoding = characterEncoding;
    }

    public void setPebbleEngine(PebbleEngine engine) {
        this.engine = engine;
    }

    public void setTemplateName(String name) {
        this.templateName = name;
    }

    @Override
    protected void renderMergedTemplateModel(Map model, HttpServletRequest request,
            HttpServletResponse response) throws Exception {

        response.setCharacterEncoding(this.characterEncoding);

        long startNanos = System.nanoTime();

        PebbleTemplate template = this.engine.getTemplate(this.templateName);

        // Add beans context
        model.put(BEANS_VARIABLE_NAME, new Beans(this.getApplicationContext()));

        // Add request & response
        model.put(REQUEST_VARIABLE_NAME, request);
        model.put(RESPONSE_VARIABLE_NAME, response);

        // Add session
        model.put(SESSION_VARIABLE_NAME, request.getSession(false));

        // Locale
        Locale locale = RequestContextUtils.getLocale(request);

        final Writer writer = response.getWriter();
        try {
            template.evaluate(writer, model, locale);
        } finally {
            writer.flush();
        }

        if (TIMER_LOGGER.isDebugEnabled()) {
            long endNanos = System.nanoTime();

            BigDecimal elapsed = BigDecimal.valueOf(endNanos - startNanos);
            BigDecimal elapsedMs = elapsed.divide(BigDecimal.valueOf(NANOS_IN_SECOND), RoundingMode.HALF_UP);
            TIMER_LOGGER.debug("Pebble template \"{}\" with locale {} processed in {} nanoseconds (approx. {}ms)",
                    new Object[] { this.templateName, locale, elapsed, elapsedMs });
        }
    }
}