// Copyright 2004, 2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package org.apache.hivemind.impl;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.hivemind.Element;
import org.apache.hivemind.ErrorLog;
import org.apache.hivemind.internal.Module;
import org.apache.hivemind.schema.ElementModel;
import org.apache.hivemind.schema.Schema;
import org.apache.hivemind.schema.SchemaProcessor;
import org.apache.hivemind.schema.Translator;
/**
* Used to assemble all the {@link org.apache.hivemind.Contribution}s contributed to an
* {@link org.apache.hivemind.ConfigurationPoint}while converting the XML (represented as
* {@link org.apache.hivemind.Element}s into Java objects.
*
* @author Howard Lewis Ship
*/
public final class SchemaProcessorImpl implements SchemaProcessor
{
private ErrorLog _errorLog;
private Schema _schema;
/**
* The assembled elements that will be contributed into the ConfigurationPoint.
*/
private List _elements = new ArrayList();
private boolean _canElementsBeMapped;
private Map _mappedElements = new HashMap();
private List _stack = new ArrayList();
private Module _module;
/**
* Map on element name to {@link SchemaElement}.
*/
private Map _elementMap = new HashMap();
/**
* Used to track the nesting of elements.
*/
private List _elementStack = new ArrayList();
public SchemaProcessorImpl(ErrorLog errorLog, Schema schema)
{
_errorLog = errorLog;
_schema = schema;
_stack.add(this);
if (_schema != null)
{
List l = _schema.getElementModel();
int count = l.size();
for (int i = 0; i < count; i++)
{
ElementModel model = (ElementModel) l.get(i);
_elementMap.put(model.getElementName(), new SchemaElement(this, model));
}
_canElementsBeMapped = schema.canInstancesBeKeyed();
}
}
/**
* Invoked over reflection by the {@link org.apache.hivemind.schema.rules.InvokeParentRule}.
*/
public void addElement(Object element)
{
_elements.add(element);
if (_canElementsBeMapped)
{
String key = peekElement().getAttributeValue(_activeElement.getKeyAttribute());
_mappedElements.put(key, element);
}
}
public List getElements()
{
return _elements;
}
public Map getMappedElements()
{
if (_canElementsBeMapped)
return _mappedElements;
return null;
}
public void push(Object object)
{
_stack.add(object);
}
public Object pop()
{
if (_stack.isEmpty())
throw new ArrayIndexOutOfBoundsException(ImplMessages.schemaStackViolation(this));
return _stack.remove(_stack.size() - 1);
}
public Object peek()
{
return peek(0);
}
public Object peek(int depth)
{
int count = _stack.size();
int position = count - 1 - depth;
if (position < 0)
throw new ArrayIndexOutOfBoundsException(ImplMessages.schemaStackViolation(this));
return _stack.get(count - 1 - depth);
}
public Module getContributingModule()
{
return _module;
}
public String getElementPath()
{
StringBuffer buffer = new StringBuffer();
int count = _elementStack.size();
for (int i = 0; i < count; i++)
{
if (i > 0)
buffer.append('/');
buffer.append(((Element) _elementStack.get(i)).getElementName());
}
return buffer.toString();
}
private void pushElement(Element element)
{
_elementStack.add(element);
}
private Element peekElement()
{
return (Element) _elementStack.get(_elementStack.size() - 1);
}
private void popElement()
{
_elementStack.remove(_elementStack.size() - 1);
}
/**
* Processes a single extension.
*/
public void process(List elements, Module contributingModule)
{
if (elements == null)
return;
if (_schema == null)
{
_elements.addAll(elements);
return;
}
_module = contributingModule;
int count = elements.size();
for (int i = 0; i < count; i++)
{
Element e = (Element) elements.get(i);
processRootElement(e);
}
_module = null;
}
private void processRootElement(Element element)
{
String name = element.getElementName();
SchemaElement schemaElement = (SchemaElement) _elementMap.get(name);
processElement(element, schemaElement);
}
private SchemaElement _activeElement;
private void processElement(Element element, SchemaElement schemaElement)
{
pushElement(element);
if (schemaElement == null)
_errorLog
.error(ImplMessages.unknownElement(this, element), element.getLocation(), null);
else
{
SchemaElement prior = _activeElement;
schemaElement.validateAttributes(element);
_activeElement = schemaElement;
schemaElement.fireBegin(element);
processNestedElements(element, schemaElement);
schemaElement.fireEnd(element);
_activeElement = prior;
}
popElement();
}
private void processNestedElements(Element element, SchemaElement schemaElement)
{
List l = element.getElements();
int count = l.size();
for (int i = 0; i < count; i++)
{
Element nested = (Element) l.get(i);
String name = nested.getElementName();
processElement(nested, schemaElement.getNestedElement(name));
}
}
public Translator getContentTranslator()
{
return _activeElement.getContentTranslator();
}
public Translator getAttributeTranslator(String attributeName)
{
return _activeElement.getAttributeTranslator(attributeName);
}
public Translator getTranslator(String translator)
{
return getContributingModule().getTranslator(translator);
}
}