NodeEvaluation.java

/* Copyright 2005-2006 Tim Fennell
 *
 * 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 net.sourceforge.stripes.util.bean;

import java.lang.reflect.Type;

/**
 * Represents a Node in an expression which has been evaluated against a specific bean in
 * order to determine additional type information etc.  NodeEvaluation is to {@link Node}, what
 * {@link PropertyExpressionEvaluation} is to {@link PropertyExpression}.
 *
 * @author Tim Fennell
 * @since Stripes 1.4
 */
public class NodeEvaluation {
    private Node node;
    private NodeType type;
    private Type valueType;
    private Class<?> keyType;
    private PropertyExpressionEvaluation expressionEvaluation;
    private NodeEvaluation next, previous;

    /**
     * Constructs a new NodeEvaluation for the specified part of an expression evaluation.
     * @param expressionEvaluation the parent expression evaluation
     * @param node the node that this evaluation is a mirror for
     */
    public NodeEvaluation(PropertyExpressionEvaluation expressionEvaluation, Node node) {
        this.expressionEvaluation = expressionEvaluation;
        this.node = node;
    }

    /** Gets the PropertyExpressionEvaluation that this NodeEvaluation is a part of. */
    public PropertyExpressionEvaluation getExpressionEvaluation() { return expressionEvaluation; }
    /** Sets the PropertyExpressionEvaluation that this NodeEvaluation is a part of. */
    public void setExpressionEvaluation(PropertyExpressionEvaluation expressionEvaluation) {
        this.expressionEvaluation = expressionEvaluation;
    }

    /** Gets the Node that is represented in the evaluation by this NodeEvaluation. */
    public Node getNode() { return node; }
    /** Sets the Node that is represented in the evaluation by this NodeEvaluation. */
    public void setNode(Node node) { this.node = node; }

    /** Gets the type of the node (bean property, list item etc.). */
    public NodeType getType() { return type; }
    /** Gets the type of the node (bean property, list item etc.). */
    public void setType(NodeType type) { this.type = type; }

    /** Gets the Type object which represents the type returned by evaluating up to this node. */
    public Type getValueType() { return valueType; }
    /** Sets the Type object which represents the type returned by evaluating up to this node. */
    public void setValueType(Type valueType) { this.valueType = valueType; }

    /**
     * Gets the class object which represents the key type determined during evaluation
     * of the expression against the provided bean. Only usually relevant for Map entries,
     * when it stores the Class specified by the generic signature of the Map.
     *
     * @return a Class object or null
     */
    public Class<?> getKeyType() { return keyType; }

    /** Gets the class object which represents the key type for this node if applicable. */
    public void setKeyType(Class<?> keyType) { this.keyType = keyType; }

    /** Gets the next NodeEvaluation in the chain, or null if this is the terminal node. */
    public NodeEvaluation getNext() { return next; }
    /** Sets the next NodeEvaluation in the chain. */
    public void setNext(NodeEvaluation next) { this.next = next; }

    /** Gets the previous NodeEvaluation in the chain, or null if this is the first node. */
    public NodeEvaluation getPrevious() { return previous; }
    /** Sets the previous NodeEvaluation in the chain. */
    public void setPrevious(NodeEvaluation previous) { this.previous = previous; }
}