/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.exoplatform.services.jcr.impl.core.query;
import org.exoplatform.services.jcr.datamodel.InternalQName;
import javax.jcr.RepositoryException;
/**
* Defines a location step for querying the path of a node.
* <br>
* {@code
* /foo -> descendants = false, nameTest = foo<br>
* //foo -> descendants = true, nameTest = foo<br>
* //* -> descendants = true, nameTest = null<br>
* /* -> descendants = false, nameTest = null<br>
* / -> descendants = false, nameTest = ""
* }
*/
public class LocationStepQueryNode extends NAryQueryNode {
/** Constant value for position index = last() */
public static final int LAST = Integer.MIN_VALUE;
/** Constant value to indicate no position index */
public static final int NONE = Integer.MIN_VALUE + 1;
/**
* The empty name used in matching the root node. This is an implementation
* specific constant as the empty name is not a valid JCR name.
*/
public static final InternalQName EMPTY_NAME = new InternalQName("", "");
/** Empty <code>QueryNode</code> array for us as return value */
private static final QueryNode[] EMPTY = new QueryNode[0];
/**
* Name test for this location step. A <code>null</code> value indicates
* a '*' name test.
*/
private InternalQName nameTest;
/**
* If set to <code>true</code> this location step uses the descendant-or-self
* axis.
*/
private boolean includeDescendants;
/**
* The context position <code>index</code>. Initially {@link #NONE}.
*/
private int index = NONE;
/**
* Creates a new <code>LocationStepQueryNode</code> that matches only
* the empty name (the repository root). The created location step
* uses only the child axis.
*/
protected LocationStepQueryNode(QueryNode parent) {
super(parent);
this.nameTest = EMPTY_NAME;
this.includeDescendants = false;
}
/**
* Returns the label of the node for this location step, or <code>null</code>
* if the name test is '*'.
* @return the label of the node for this location step.
*/
public InternalQName getNameTest() {
return nameTest;
}
/**
* Sets a new name test.
* @param nameTest the name test or <code>null</code> to match all names.
*/
public void setNameTest(InternalQName nameTest) {
this.nameTest = nameTest;
}
/**
* Returns <code>true</code> if this location step uses the
* descendant-or-self axis, <code>false</code> if this step uses the child
* axis.
* @return <code>true</code> if this step uses the descendant-or-self axis.
*/
public boolean getIncludeDescendants() {
return includeDescendants;
}
/**
* Sets a new value for the includeDescendants property.
* @param include the new value.
* @see #getIncludeDescendants()
*/
public void setIncludeDescendants(boolean include) {
this.includeDescendants = include;
}
/**
* Adds a predicate node to this location step.
* @param predicate the node to add.
*/
public void addPredicate(QueryNode predicate) {
addOperand(predicate);
}
/**
* Returns the predicate nodes for this location step. This method may
* also return a position predicate.
* @return the predicate nodes or an empty array if there are no predicates
* for this location step.
*/
public QueryNode[] getPredicates() {
if (operands == null) {
return EMPTY;
} else {
return (QueryNode[]) operands.toArray(new QueryNode[operands.size()]);
}
}
/**
* Sets the position index for this step. A value of {@link #NONE} indicates
* that this location step has no position index assigned. That is, the
* step selects all same name siblings.
* @param index the position index.
*/
public void setIndex(int index) {
this.index = index;
}
/**
* Returns the position index for this step. A value of {@link #NONE} indicates
* that this location step has no position index assigned. That is, the
* step selects all same name siblings.
* @return the position index for this step.
*/
public int getIndex() {
return index;
}
/**
* {@inheritDoc}
* @throws RepositoryException
*/
public Object accept(QueryNodeVisitor visitor, Object data) throws RepositoryException {
return visitor.visit(this, data);
}
/**
* {@inheritDoc}
*/
public int getType() {
return QueryNode.TYPE_LOCATION;
}
/**
* {@inheritDoc}
*/
public boolean equals(Object obj) {
if (obj instanceof LocationStepQueryNode) {
LocationStepQueryNode other = (LocationStepQueryNode) obj;
return super.equals(other)
&& includeDescendants == other.includeDescendants
&& index == other.index
&& (nameTest == null ? other.nameTest == null : nameTest.equals(other.nameTest));
}
return false;
}
}