/**
* Logback: the generic, reliable, fast and flexible logging framework.
*
* Copyright (C) 2000-2009, QOS.ch
*
* This library is free software, you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation.
*/
package ch.qos.logback.core.joran.action;
import java.util.Stack;
import org.xml.sax.Attributes;
import ch.qos.logback.core.joran.spi.InterpretationContext;
import ch.qos.logback.core.joran.spi.Pattern;
import ch.qos.logback.core.joran.spi.PropertySetter;
import ch.qos.logback.core.spi.ContextAware;
import ch.qos.logback.core.spi.LifeCycle;
import ch.qos.logback.core.util.AggregationType;
import ch.qos.logback.core.util.Loader;
import ch.qos.logback.core.util.OptionHelper;
/**
* This action is responsible for tying together a parent object with a child
* element for which there is no explicit rule.
*
* @author Ceki Gülcü
*/
public class NestedComplexPropertyIA extends ImplicitAction {
// actionDataStack contains ActionData instances
// We use a stack of ActionData objects in order to support nested
// elements which are handled by the same NestedComplexPropertyIA instance.
// We push a ActionData instance in the isApplicable method (if the
// action is applicable) and pop it in the end() method.
// The XML well-formedness property will guarantee that a push will eventually
// be followed by a corresponding pop.
Stack<IADataForComplexProperty> actionDataStack = new Stack<IADataForComplexProperty>();
public boolean isApplicable(Pattern pattern, Attributes attributes,
InterpretationContext ic) {
String nestedElementTagName = pattern.peekLast();
// calling ic.peekObject with an empty stack will throw an exception
if (ic.isEmpty()) {
return false;
}
Object o = ic.peekObject();
PropertySetter parentBean = new PropertySetter(o);
parentBean.setContext(context);
AggregationType aggregationType = parentBean
.computeAggregationType(nestedElementTagName);
switch (aggregationType) {
case NOT_FOUND:
case AS_BASIC_PROPERTY:
case AS_BASIC_PROPERTY_COLLECTION:
return false;
// we only push action data if NestComponentIA is applicable
case AS_COMPLEX_PROPERTY_COLLECTION:
case AS_COMPLEX_PROPERTY:
IADataForComplexProperty ad = new IADataForComplexProperty(parentBean,
aggregationType, nestedElementTagName);
actionDataStack.push(ad);
return true;
default:
addError("PropertySetter.computeAggregationType returned "
+ aggregationType);
return false;
}
}
public void begin(InterpretationContext ec, String localName,
Attributes attributes) {
// LogLog.debug("in NestComponentIA begin method");
// get the action data object pushed in isApplicable() method call
IADataForComplexProperty actionData = (IADataForComplexProperty) actionDataStack
.peek();
String className = attributes.getValue(CLASS_ATTRIBUTE);
// perform variable name substitution
className = ec.subst(className);
Class componentClass = null;
try {
if (!OptionHelper.isEmpty(className)) {
componentClass = Loader.loadClass(className, context);
} else {
// guess class name via implicit rules
PropertySetter parentBean = actionData.parentBean;
componentClass = parentBean.getClassNameViaImplicitRules(actionData
.getComplexPropertyName(), actionData.getAggregationType(), ec
.getDefaultNestedComponentRegistry());
}
if (componentClass == null) {
actionData.inError = true;
String errMsg = "Could not find an appropriate class for property ["
+ localName + "]";
addError(errMsg);
return;
}
if(OptionHelper.isEmpty(className)) {
addInfo("Assuming default type ["+componentClass.getName()+"] for ["+localName+"] property");
}
actionData.setNestedComplexProperty(componentClass.newInstance());
// pass along the repository
if (actionData.getNestedComplexProperty() instanceof ContextAware) {
((ContextAware) actionData.getNestedComplexProperty())
.setContext(this.context);
}
// getLogger().debug(
addInfo("Pushing component [" + localName
+ "] on top of the object stack.");
ec.pushObject(actionData.getNestedComplexProperty());
} catch (Exception oops) {
actionData.inError = true;
String msg = "Could not create component [" + localName + "] of type ["
+ className + "]";
addError(msg, oops);
}
}
public void end(InterpretationContext ec, String tagName) {
// pop the action data object pushed in isApplicable() method call
// we assume that each this begin
IADataForComplexProperty actionData = (IADataForComplexProperty) actionDataStack
.pop();
if (actionData.inError) {
return;
}
PropertySetter nestedBean = new PropertySetter(actionData
.getNestedComplexProperty());
nestedBean.setContext(context);
// have the nested element point to its parent if possible
if (nestedBean.computeAggregationType("parent") == AggregationType.AS_COMPLEX_PROPERTY) {
nestedBean.setComplexProperty("parent", actionData.parentBean.getObj());
}
// start the nested complex attribute if it implements LifeCycle
if (actionData.getNestedComplexProperty() instanceof LifeCycle) {
((LifeCycle) actionData.getNestedComplexProperty()).start();
}
Object o = ec.peekObject();
if (o != actionData.getNestedComplexProperty()) {
addError("The object on the top the of the stack is not the component pushed earlier.");
} else {
ec.popObject();
// Now let us attach the component
switch (actionData.aggregationType) {
case AS_COMPLEX_PROPERTY:
actionData.parentBean.setComplexProperty(tagName, actionData
.getNestedComplexProperty());
break;
case AS_COMPLEX_PROPERTY_COLLECTION:
actionData.parentBean.addComplexProperty(tagName, actionData
.getNestedComplexProperty());
break;
}
}
}
}