Commons JXPath example source code file (VariablePointerFactory.java)

This example Commons JXPath source code file (VariablePointerFactory.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons JXPath tags/keywords

jxpathcontext, jxpathcontext, locale, nodepointer, object, object, qname, util, variable_pointer_factory_order, variablecontextwrapper, variablecontextwrapper, variablepointer, variablepointer, variablepointerfactory, variables

The Commons JXPath VariablePointerFactory.java source code

/*
 * 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.apache.commons.jxpath.ri.model;

import java.util.Locale;

import org.apache.commons.jxpath.JXPathContext;
import org.apache.commons.jxpath.Variables;
import org.apache.commons.jxpath.ri.QName;

/**
 * NodePointerFactory to create {@link VariablePointer VariablePointers}.
 * @author Matt Benson
 * @since JXPath 1.3
 * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
 */
public class VariablePointerFactory implements NodePointerFactory {
    /** factory order constant */
    public static final int VARIABLE_POINTER_FACTORY_ORDER = 890;

    /**
     * Node value wrapper to trigger a VariablePointerFactory.
     */
    public static final class VariableContextWrapper {
        private final JXPathContext context;

        /**
         * Create a new VariableContextWrapper.
         * @param context to wrap
         */
        private VariableContextWrapper(JXPathContext context) {
            this.context = context;
        }

        /**
         * Get the original (unwrapped) context.
         *
         * @return JXPathContext.
         */
        public JXPathContext getContext() {
            return context;
        }
    }

    /**
     * VariableContextWrapper factory method.
     * @param context the JXPathContext to wrap.
     * @return VariableContextWrapper.
     */
    public static VariableContextWrapper contextWrapper(JXPathContext context) {
        return new VariableContextWrapper(context);
    }

    public NodePointer createNodePointer(QName name, Object object,
            Locale locale) {
        if (object instanceof VariableContextWrapper) {
            JXPathContext varCtx = ((VariableContextWrapper) object).getContext();
            while (varCtx != null) {
                Variables vars = varCtx.getVariables();
                if (vars.isDeclaredVariable(name.toString())) {
                    return new VariablePointer(vars, name);
                }
                varCtx = varCtx.getParentContext();
            }
            // The variable is not declared, but we will create
            // a pointer anyway in case the user wants to set, rather
            // than get, the value of the variable.
            return new VariablePointer(name);
        }
        return null;
    }

    public NodePointer createNodePointer(NodePointer parent, QName name,
            Object object) {
        return createNodePointer(name, object, null);
    }

    public int getOrder() {
        return VARIABLE_POINTER_FACTORY_ORDER;
    }

}