juneau-rest/src/main/java/org/apache/juneau/rest/vars/RequestVar.java

// ***************************************************************************************************************************
// * 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.juneau.rest.vars;

import org.apache.juneau.internal.*;
import org.apache.juneau.rest.*;
import org.apache.juneau.svl.*;

/**
 * Request attribute variable resolver.
 * <p>
 * The format for this var is <js>"$R{key}"</js>.
 * The possible values are:
 * <ul>
 * 	<li><code>$R{contextPath}</code> - Value returned by {@link RestRequest#getContextPath()}.
 * 	<li><code>$R{method}</code> - Value returned by {@link RestRequest#getMethod()}.
 * 	<li><code>$R{methodDescription}</code> - Value returned by {@link RestRequest#getMethodDescription()}.
 * 	<li><code>$R{pathInfo}</code> - Value returned by {@link RestRequest#getPathInfo()}.
 * 	<li><code>$R{requestParentURI}</code> - Value returned by {@link RestRequest#getRequestParentURI()}.
 * 	<li><code>$R{requestURI}</code> - Value returned by {@link RestRequest#getRequestURI()}.
 * 	<li><code>$R{servletDescription}</code> - Value returned by {@link RestRequest#getServletDescription()}.
 * 	<li><code>$R{servletTitle}</code> - Value returned by {@link RestRequest#getServletTitle()}.
 * 	<li><code>$R{servletParentURI}</code> - Value returned by {@link RestRequest#getServletParentURI()}.
 * 	<li><code>$R{servletPath}</code> - Value returned by {@link RestRequest#getServletPath()}.
 * 	<li><code>$R{servletURI}</code> - Value returned by {@link RestRequest#getServletURI()}.
 * 	<li><code>$R{trimmedRequestURI}</code> - Value returned by {@link RestRequest#getTrimmedRequestURI()}.
 * </ul>
 * <p>
 * This variable resolver requires that a {@link RestRequest} object be set as a context object on the resolver or a
 * 	session object on the resolver session.
 * <p>
 * Since this is a {@link SimpleVar}, any variables contained in the result will be recursively resolved.
 * Likewise, if the arguments contain any variables, those will be resolved before they are passed to this var.
 *
 * @see org.apache.juneau.svl
 */
public class RequestVar extends SimpleVar {

	/**
	 * The name of the session or context object that identifies the {@link RestRequest} object.
	 */
	public static final String SESSION_req = "req";

	/**
	 * Constructor.
	 */
	public RequestVar() {
		super("R");
	}

	@Override /* Parameter */
	public String resolve(VarResolverSession session, String key) {
		RestRequest req = session.getSessionObject(RestRequest.class, SESSION_req);
		if (key.length() > 0) {
				String k = key.toString();
				if (k.indexOf('.') != -1) {
					String prefix = k.substring(0, k.indexOf('.'));
					String remainder = k.substring(k.indexOf('.')+1);
					if ("path".equals(prefix))
						return req.getPathParameter(remainder);
					if ("query".equals(prefix))
						return req.getQueryParameter(remainder);
					if ("formData".equals(prefix))
						return req.getFormDataParameter(remainder);
					if ("header".equals(prefix))
						return req.getHeader(remainder);
					if ("attribute".equals(prefix))
						return StringUtils.toString(req.getAttribute(remainder));
				}
				char c = key.charAt(0);
				if (c == 'c') {
					if (key.equals("contextPath"))
						return req.getContextPath();
				} else if (c == 'm') {
					if (key.equals("method"))
						return req.getMethod();
					if (key.equals("methodSummary"))
						return req.getMethodSummary();
					if (key.equals("methodDescription"))
						return req.getMethodDescription();
				} else if (c == 'p') {
					if (key.equals("pathInfo"))
						return req.getPathInfo();
				} else if (c == 'r') {
					if (key.equals("requestURI"))
						return req.getRequestURI();
					if (key.equals("relativeServletURI"))
						return req.getRelativeServletURI();
					if (key.equals("requestParentURI"))
						return req.getRequestParentURI();
				} else if (c == 's') {
					if (key.equals("servletPath"))
						return req.getServletPath();
					if (key.equals("servletURI"))
						return req.getServletURI();
					if (key.equals("servletParentURI"))
						return req.getServletParentURI();
					if (key.equals("servletTitle"))
						return req.getServletTitle();
					if (key.equals("servletDescription"))
						return req.getServletDescription();
				} else if (c == 't') {
					if (key.equals("trimmedRequestURI"))
						return req.getTrimmedRequestURI();
				}
				Object o = req.getProperties().get(key);
				if (o != null)
					return o.toString();
				return req.getPathParameter(key);
			}
		return null;
	}
}