001/**
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2022, QOS.ch. All rights reserved.
004 *
005 * This program and the accompanying materials are dual-licensed under
006 * either the terms of the Eclipse Public License v1.0 as published by
007 * the Eclipse Foundation
008 *
009 *   or (per the licensee's choosing)
010 *
011 * under the terms of the GNU Lesser General Public License version 2.1
012 * as published by the Free Software Foundation.
013 */
014package ch.qos.logback.core.model.processor;
015
016import ch.qos.logback.core.Context;
017import ch.qos.logback.core.joran.action.ActionUtil;
018import ch.qos.logback.core.joran.action.ActionUtil.Scope;
019import ch.qos.logback.core.model.DefineModel;
020import ch.qos.logback.core.model.Model;
021import ch.qos.logback.core.spi.LifeCycle;
022import ch.qos.logback.core.spi.PropertyDefiner;
023import ch.qos.logback.core.util.OptionHelper;
024
025/**
026 * Instantiate class for define property value. Get future property name and
027 * property definer class from attributes. Some property definer properties
028 * could be used. After defining put new property to context.
029 * 
030 * @author Aleksey Didik
031 */
032public class DefineModelHandler extends ModelHandlerBase {
033
034    boolean inError;
035    PropertyDefiner definer;
036    String propertyName;
037    Scope scope;
038
039    public DefineModelHandler(Context context) {
040        super(context);
041    }
042
043    static public DefineModelHandler makeInstance(Context context, ModelInterpretationContext ic) {
044        return new DefineModelHandler(context);
045    }
046
047    @Override
048    protected Class<DefineModel> getSupportedModelClass() {
049        return DefineModel.class;
050    }
051
052    @Override
053    public void handle(ModelInterpretationContext interpretationContext, Model model) throws ModelHandlerException {
054        definer = null;
055        inError = false;
056        propertyName = null;
057
058        DefineModel defineModel = (DefineModel) model;
059
060        propertyName = defineModel.getName();
061        String scopeStr = defineModel.getScopeStr();
062
063        scope = ActionUtil.stringToScope(scopeStr);
064
065        if (OptionHelper.isNullOrEmpty(propertyName)) {
066            addError("Missing property name for property definer. Near [" + model.getTag() + "] line "
067                    + model.getLineNumber());
068            inError = true;
069        }
070
071        // read property definer class name
072        String className = defineModel.getClassName();
073        if (OptionHelper.isNullOrEmpty(className)) {
074            addError("Missing class name for property definer. Near [" + model.getTag() + "] line "
075                    + model.getLineNumber());
076            inError = true;
077        } else {
078            className = interpretationContext.getImport(className);
079        }
080
081        if (inError)
082            return;
083
084        // try to instantiate property definer
085        try {
086            addInfo("About to instantiate property definer of type [" + className + "]");
087            definer = (PropertyDefiner) OptionHelper.instantiateByClassName(className, PropertyDefiner.class, context);
088            definer.setContext(context);
089            interpretationContext.pushObject(definer);
090        } catch (Exception oops) {
091            inError = true;
092            addError("Could not create an PropertyDefiner of type [" + className + "].", oops);
093            throw new ModelHandlerException(oops);
094        }
095
096    }
097
098    /**
099     * Now property definer is initialized by all properties and we can put property
100     * value to context
101     */
102    @Override
103    public void postHandle(ModelInterpretationContext interpretationContext, Model model) throws ModelHandlerException {
104        if (inError) {
105            return;
106        }
107
108        Object o = interpretationContext.peekObject();
109
110        if (o != definer) {
111            addWarn("The object at the of the stack is not the property definer for property named [" + propertyName
112                    + "] pushed earlier.");
113        } else {
114            interpretationContext.popObject();
115            if (definer instanceof LifeCycle)
116                ((LifeCycle) definer).start();
117
118            // let's put defined property and value to context but only if it is
119            // not null
120            String propertyValue = definer.getPropertyValue();
121            if (propertyValue != null) {
122                addInfo("Setting property " + propertyName + "=" + propertyValue + " in scope " + scope);
123                ActionUtil.setProperty(interpretationContext, propertyName, propertyValue, scope);
124            }
125        }
126
127    }
128}