Logback: the reliable, generic, fast and flexible logging framework.
Copyright (C) 1999-2015, QOS.ch. All rights reserved.
This program and the accompanying materials are dual-licensed under
either the terms of the Eclipse Public License v1.0 as published by
the Eclipse Foundation
  or (per the licensee's choosing)
under the terms of the GNU Lesser General Public License version 2.1
as published by the Free Software Foundation.
/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.pattern;

import java.util.HashMap;
import java.util.Map;

import ch.qos.logback.core.Context;
import ch.qos.logback.core.CoreConstants;
import ch.qos.logback.core.LayoutBase;
import ch.qos.logback.core.pattern.parser.Node;
import ch.qos.logback.core.pattern.parser.Parser;
import ch.qos.logback.core.spi.ScanException;
import ch.qos.logback.core.status.ErrorStatus;
import ch.qos.logback.core.status.StatusManager;

abstract public class PatternLayoutBase<E> extends LayoutBase<E> {

    static final int INTIAL_STRING_BUILDER_SIZE = 256;
    Converter<E> head;
    String pattern;
    protected PostCompileProcessor<E> postCompileProcessor;
    
    Map<String, String> instanceConverterMap = new HashMap<String, String>();
    protected boolean outputPatternAsHeader = false;
    
    
Concrete implementations of this class are responsible for elaborating the
mapping between pattern words and converters.
Returns:
A map associating pattern words to the names of converter classes/**
     * Concrete implementations of this class are responsible for elaborating the
     * mapping between pattern words and converters.
     * 
     * @return A map associating pattern words to the names of converter classes
     */
    abstract public Map<String, String> getDefaultConverterMap();

    
Returns a map where the default converter map is merged with the map
contained in the context.
/**
     * Returns a map where the default converter map is merged with the map
     * contained in the context.
     */
    public Map<String, String> getEffectiveConverterMap() {
        Map<String, String> effectiveMap = new HashMap<String, String>();

        // add the least specific map fist
        Map<String, String> defaultMap = getDefaultConverterMap();
        if (defaultMap != null) {
            effectiveMap.putAll(defaultMap);
        }

        // contextMap is more specific than the default map
        Context context = getContext();
        if (context != null) {
            @SuppressWarnings("unchecked")
            Map<String, String> contextMap = (Map<String, String>) context.getObject(CoreConstants.PATTERN_RULE_REGISTRY);
            if (contextMap != null) {
                effectiveMap.putAll(contextMap);
            }
        }
        // set the most specific map last
        effectiveMap.putAll(instanceConverterMap);
        return effectiveMap;
    }

    public void start() {
        if (pattern == null || pattern.length() == 0) {
            addError("Empty or null pattern.");
            return;
        }
        try {
            Parser<E> p = new Parser<E>(pattern);
            if (getContext() != null) {
                p.setContext(getContext());
            }
            Node t = p.parse();
            this.head = p.compile(t, getEffectiveConverterMap());
            if (postCompileProcessor != null) {
                postCompileProcessor.process(context, head);
            }
            ConverterUtil.setContextForConverters(getContext(), head);
            ConverterUtil.startConverters(this.head);
            super.start();
        } catch (ScanException sce) {
            StatusManager sm = getContext().getStatusManager();
            sm.add(new ErrorStatus("Failed to parse pattern \"" + getPattern() + "\".", this, sce));
        }
    }

    public void setPostCompileProcessor(PostCompileProcessor<E> postCompileProcessor) {
        this.postCompileProcessor = postCompileProcessor;
    }

    
Params:
head – 
Deprecated:
 Use ConverterUtil.setContextForConverters instead. This method will be removed in future releases./**
     *
     * @param head
     * @deprecated  Use {@link ConverterUtil#setContextForConverters} instead. This method will
     *  be removed in future releases.
     */
    protected void setContextForConverters(Converter<E> head) {
        ConverterUtil.setContextForConverters(getContext(), head);
    }

    protected String writeLoopOnConverters(E event) {
        StringBuilder strBuilder = new StringBuilder(INTIAL_STRING_BUILDER_SIZE);
        Converter<E> c = head;
        while (c != null) {
            c.write(strBuilder, event);
            c = c.getNext();
        }
        return strBuilder.toString();
    }

    public String getPattern() {
        return pattern;
    }

    public void setPattern(String pattern) {
        this.pattern = pattern;
    }

    public String toString() {
        return this.getClass().getName() + "(\"" + getPattern() + "\")";
    }

    public Map<String, String> getInstanceConverterMap() {
        return instanceConverterMap;
    }

    protected String getPresentationHeaderPrefix() {
        return CoreConstants.EMPTY_STRING;
    }

    public boolean isOutputPatternAsHeader() {
        return outputPatternAsHeader;
    }

    public void setOutputPatternAsHeader(boolean outputPatternAsHeader) {
        this.outputPatternAsHeader = outputPatternAsHeader;
    }

    @Override
    public String getPresentationHeader() {
        if (outputPatternAsHeader)
            return getPresentationHeaderPrefix() + pattern;
        else
            return super.getPresentationHeader();
    }
}