/*******************************************************************************
* Copyright (c) 2007 Oracle Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Oracle - initial API and implementation
*
********************************************************************************/
package org.eclipse.jst.jsf.common.metadata.query.internal;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
import org.eclipse.jst.jsf.common.metadata.Entity;
import org.eclipse.jst.jsf.common.metadata.query.AbstractEntityQueryVisitor;
import org.eclipse.jst.jsf.common.metadata.query.IResultSet;
/**
* A simple metadata query visitor implementing {@link org.eclipse.jst.jsf.common.metadata.query.IEntityQueryVisitor} and {@link org.eclipse.jst.jsf.common.metadata.query.ITraitQueryVisitor}.<p>
* - simple find entity and traits by id only <br>
* - does not allow for wild card searchs<br>
* <p>
* TODO - fix for case-sensitivity https://bugs.eclipse.org/bugs/show_bug.cgi?id=212794
*
*/
public class SimpleEntityQueryVisitorImpl extends AbstractEntityQueryVisitor implements IHierarchicalEntityVisitor {
private HierarchicalSearchControl control;
private boolean _stop;
private EntityQueryFilterVisitor entityQuery;
private List<Entity> _entityResults;
private Entity initialEntityContext;
/**
* Constructor that also creates a default SearchControl
*/
public SimpleEntityQueryVisitorImpl() {
super();
control = new HierarchicalSearchControl();
}
/**
* Constructor
* @param control
*/
public SimpleEntityQueryVisitorImpl(final HierarchicalSearchControl control) {
super();
this.control = control;
}
/* (non-Javadoc)
* @see org.eclipse.jst.jsf.common.metadata.query.IEntityQueryVisitor#findEntities(org.eclipse.jst.jsf.common.metadata.Entity, java.lang.String)
*/
public IResultSet<Entity> findEntities(final Entity initialEntity,
final String entityKey) {
resetQuery();
if (initialEntity != null){
this.initialEntityContext = initialEntity;
entityQuery = new EntityQueryFilterVisitor(initialEntity.getId(), entityKey);
initialEntity.accept(this);
}
return new SimpleResultSet(getInternalEntityResults());
}
private void resetQuery() {
_stop = false;
_entityResults = null;
}
private List<Entity> getInternalEntityResults(){
if (_entityResults == null){
_entityResults = new ArrayList<Entity>();
}
return _entityResults;
}
public boolean visitEnter(final Entity entity) {
if (entity == initialEntityContext)
return true;
entityQuery.pushLevel();
if (entityQuery.canVisit(entity))
return entityQuery.visit(entity);
return false;
}
public boolean visitLeave(Entity entity) {
checkShouldStopVisitingEntities();
if (entity != initialEntityContext)
entityQuery.popLevel();
return true;
}
/* (non-Javadoc)
* @see org.eclipse.jst.jsf.common.metadata.query.IEntityVisitor#visit(org.eclipse.jst.jsf.common.metadata.Entity)
*/
public void visit(final Entity key) {
//do nothing... all work now done in visitEnter/visitLeave
}
/* (non-Javadoc)
* @see org.eclipse.jst.jsf.common.metadata.query.IMetaDataVisitor#stopVisiting()
*/
public boolean stopVisiting() {
return _stop;
}
private void checkShouldStopVisitingEntities(){
//implement how to set stop to signal to the entity accept() to skip visiting
if (_stop == false
&& control.getCountLimit()== getInternalEntityResults().size()
&& control.getCountLimit() != SearchControl.COUNT_LIMIT_NONE )
_stop = true;
}
/**
* Visitor that filters and acts upon hierarchical data that compares that an entity's id for with another with case-insensitive compare
*/
private class EntityQueryFilterVisitor {
private String entityId;
private List<String> entityQueue;
private int curLevel = 0;
/**
* Constructor
* @param initialContextId - Entity id from which the query is rooted
* @param queryKey - query key which may be compound ("A/B/C" - assuming "/" is the delimiter)
*/
public EntityQueryFilterVisitor(final String initialContextId, final String queryKey){
init(initialContextId, queryKey);
}
private void init(final String initialContextId, final String key) {
entityQueue = new ArrayList<String>(3);
addLevel(initialContextId);
if (key == null || key.trim().equals("") || key.trim().equals(getLevelDelimiter())){ //$NON-NLS-1$
addLevel(""); //$NON-NLS-1$
}
else {
final StringTokenizer st = new StringTokenizer(key, getLevelDelimiter());
String partialKey = st.nextToken();
addLevel(partialKey);
while (st.hasMoreElements()){
partialKey = st.nextToken();
addLevel(partialKey);
}
}
}
/**
* @param entity
* @return flag indicating that filter was passed and children may be visited
*/
public boolean canVisit(final Entity entity) {
// only one filter rule... does this entity id match the current level's entity id (case-insensitive)
return entityId.compareTo(entity.getId().toUpperCase()) == 0;
}
/**
* Operates on passed entity and determines if it should be part of the query results
* @param entity
* @return true if children of entity should be visited
*/
public boolean visit(final Entity entity) {
//one operation... if we have found the leaf-most entity in the query, add it to the results and go no deeper
if (curLevel == entityQueue.size() - 1) {
getInternalEntityResults().add(entity);
return false;
}
return true;
}
private void addLevel(final String key) {
entityQueue.add(key.toUpperCase());
}
/**
* Move up one level in the query
*/
public void popLevel(){
entityId = entityQueue.get(--curLevel);
}
/**
* Move down one level in the query
*/
public void pushLevel() {
entityId = entityQueue.get(++curLevel);
}
}
}