    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *     http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.jxpath.servlet;
    019
    020import java.util.Enumeration;
    021
    022import javax.servlet.jsp.PageContext;
    023
    024/**
    025 * A lightweight wrapper for {@link PageContext} that restricts access to attributes of the "page" scope. This object is needed so that XPath "foo" would lookup
    026 * the attribute "foo" in all scopes, while "$page/foo" would only look in the "page" scope.
    027 */
    028public class PageScopeContext {
    029
    030    private final PageContext pageContext;
    031
    032    /**
    033     * Constructs a new PageScopeContext.
    034     *
    035     * @param pageContext base
    036     */
    037    public PageScopeContext(final PageContext pageContext) {
    038        this.pageContext = pageContext;
    039    }
    040
    041    /**
    042     * Gets the value of the specified attribute.
    043     *
    044     * @param attribute name
    045     * @return Object
    046     */
    047    public Object getAttribute(final String attribute) {
    048        return pageContext.getAttribute(attribute, PageContext.PAGE_SCOPE);
    049    }
    050
    051    /**
    052     * Returns attributes of the pageContext declared in the "page" scope.
    053     *
    054     * @return Enumeration of attribute names
    055     */
    056    public Enumeration<String> getAttributeNames() {
    057        return pageContext.getAttributeNamesInScope(PageContext.PAGE_SCOPE);
    058    }
    059
    060    /**
    061     * Sets the specified attribute.
    062     *
    063     * @param attribute to set
    064     * @param value     to set
    065     */
    066    public void setAttribute(final String attribute, final Object value) {
    067        pageContext.setAttribute(attribute, value, PageContext.PAGE_SCOPE);
    068    }
    069}