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.joran.action;

import org.xml.sax.Attributes;

import ch.qos.logback.core.Appender;
import ch.qos.logback.core.CoreConstants;
import ch.qos.logback.core.joran.spi.InterpretationContext;
import ch.qos.logback.core.spi.AppenderAttachable;
import ch.qos.logback.core.util.OptionHelper;

import java.util.HashMap;

public class AppenderRefAction<E> extends Action {
    boolean inError = false;

    @SuppressWarnings("unchecked")
    public void begin(InterpretationContext ec, String tagName, Attributes attributes) {
        // Let us forget about previous errors (in this object)
        inError = false;

        // logger.debug("begin called");

        Object o = ec.peekObject();

        if (!(o instanceof AppenderAttachable)) {
            String errMsg = "Could not find an AppenderAttachable at the top of execution stack. Near [" + tagName + "] line " + getLineNumber(ec);
            inError = true;
            addError(errMsg);
            return;
        }

        AppenderAttachable<E> appenderAttachable = (AppenderAttachable<E>) o;

        String appenderName = ec.subst(attributes.getValue(ActionConst.REF_ATTRIBUTE));

        if (OptionHelper.isEmpty(appenderName)) {
            // print a meaningful error message and return
            String errMsg = "Missing appender ref attribute in <appender-ref> tag.";
            inError = true;
            addError(errMsg);

            return;
        }

        HashMap<String, Appender<E>> appenderBag = (HashMap<String, Appender<E>>) ec.getObjectMap().get(ActionConst.APPENDER_BAG);
        Appender<E> appender = (Appender<E>) appenderBag.get(appenderName);

        if (appender == null) {
            String msg = "Could not find an appender named [" + appenderName + "]. Did you define it below instead of above in the configuration file?";
            inError = true;
            addError(msg);
            addError("See " + CoreConstants.CODES_URL + "#appender_order for more details.");
            return;
        }

        addInfo("Attaching appender named [" + appenderName + "] to " + appenderAttachable);
        appenderAttachable.addAppender(appender);
    }

    public void end(InterpretationContext ec, String n) {
    }

}