UrlTagHDIV.java

/**
 * Copyright 2005-2010 hdiv.org
 *
 * 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 org.hdiv.web.servlet.tags;

import java.io.IOException;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hdiv.config.HDIVConfig;
import org.hdiv.util.HDIVRequestUtils;
import org.hdiv.util.HDIVUtil;
import org.springframework.web.servlet.tags.Param;
import org.springframework.web.servlet.tags.UrlTag;
import org.springframework.web.util.ExpressionEvaluationUtils;
import org.springframework.web.util.HtmlUtils;
import org.springframework.web.util.JavaScriptUtils;
import org.springframework.web.util.TagUtils;

public class UrlTagHDIV extends UrlTag {

	/**
	 * Commons Logging instance.
	 */
	private static Log log = LogFactory.getLog(UrlTagHDIV.class);
	
	private static final String URL_TEMPLATE_DELIMITER_PREFIX = "{";

	private static final String URL_TEMPLATE_DELIMITER_SUFFIX = "}";

	private static final String URL_TYPE_ABSOLUTE = "://";

	private List<Param> params;

	private Set<String> templateParams;

	private UrlType type;

	private String value;

	private String context;

	private String var;

	private int scope = PageContext.PAGE_SCOPE;

	private boolean javaScriptEscape = false;


	/**
	 * Sets the value of the URL
	 */
	public void setValue(String value) {
		if (value.contains(URL_TYPE_ABSOLUTE)) {
			this.type = UrlType.ABSOLUTE;
			this.value = value;
		}
		else if (value.startsWith("/")) {
			this.type = UrlType.CONTEXT_RELATIVE;
			this.value = value;
		}
		else {
			this.type = UrlType.RELATIVE;
			this.value = value;
		}
	}

	/**
	 * Set the context path for the URL. Defaults to the current context
	 */
	public void setContext(String context) {
		if (context.startsWith("/")) {
			this.context = context;
		}
		else {
			this.context = "/" + context;
		}
	}

	/**
	 * Set the variable name to expose the URL under. Defaults to rendering the
	 * URL to the current JspWriter
	 */
	public void setVar(String var) {
		this.var = var;
	}

	/**
	 * Set the scope to export the URL variable to. This attribute has no
	 * meaning unless var is also defined.
	 */
	public void setScope(String scope) {
		this.scope = TagUtils.getScope(scope);
	}

	/**
	 * Set JavaScript escaping for this tag, as boolean value.
	 * Default is "false".
	 */
	public void setJavaScriptEscape(String javaScriptEscape) throws JspException {
		this.javaScriptEscape =
				ExpressionEvaluationUtils.evaluateBoolean("javaScriptEscape", javaScriptEscape, pageContext);
	}

	public void addParam(Param param) {
		this.params.add(param);
	}


	@Override
	public int doStartTagInternal() throws JspException {
		this.params = new LinkedList<Param>();
		this.templateParams = new HashSet<String>();
		return EVAL_BODY_INCLUDE;
	}

	@Override
	public int doEndTag() throws JspException {
		String url = createUrl();
		
		if (this.var == null) {
			// print the url to the writer
			try {
				pageContext.getOut().print(url);
			}
			catch (IOException e) {
				throw new JspException(e);
			}
		}
		else {
			// store the url as a variable
			pageContext.setAttribute(var, url, scope);
		}
		return EVAL_PAGE;
	}


	/**
	 * Build the URL for the tag from the tag attributes and parameters.
	 * @return the URL value as a String
	 * @throws JspException
	 */
	private String createUrl() throws JspException {
		HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
		HttpServletResponse response = (HttpServletResponse) pageContext.getResponse();
		StringBuilder url = new StringBuilder();
		if (this.type == UrlType.CONTEXT_RELATIVE) {
			// add application context to url
			if (this.context == null) {
				url.append(request.getContextPath());
			}
			else {
				url.append(this.context);
			}
		}
		if (this.type != UrlType.RELATIVE && this.type != UrlType.ABSOLUTE && !this.value.startsWith("/")) {
			url.append("/");
		}
		url.append(replaceUriTemplateParams(this.value, this.params, this.templateParams));
		url.append(createQueryString(this.params, this.templateParams, (url.indexOf("?") == -1)));

		String urlStr = url.toString();
		
		urlStr = HDIVRequestUtils.composeLinkUrl(urlStr, request);
		
//		HDIVConfig hdivConfig = (HDIVConfig) HDIVUtil.getHDIVConfig(pageContext.getServletContext());
//		
//		if (!HDIVRequestUtils.hasExtensionToExclude(urlStr, hdivConfig.getExcludedURLExtensions()))
//		{
//			if (HDIVRequestUtils.hasActionOrServletExtension(urlStr, hdivConfig.getProtectedURLPatterns())) {
//				urlStr = HDIVRequestUtils.addHDIVParameterIfNecessary((HttpServletRequest) pageContext.getRequest(), 
//						urlStr, hdivConfig.isValidationInUrlsWithoutParamsActivated());
//			}
//		}
		
		if (this.type != UrlType.ABSOLUTE) {
			// Add the session identifier if needed
			// (Do not embed the session identifier in a remote link!)
			urlStr = response.encodeURL(urlStr);
		}

		// HTML and/or JavaScript escape, if demanded.
		urlStr = isHtmlEscape() ? HtmlUtils.htmlEscape(urlStr) : urlStr;
		urlStr = this.javaScriptEscape ? JavaScriptUtils.javaScriptEscape(urlStr) : urlStr;
		
		return urlStr;
	}

	/**
	 * Build the query string from available parameters that have not already
	 * been applied as template params.
	 * <p>The names and values of parameters are URL encoded.
	 * @param params the parameters to build the query string from
	 * @param usedParams set of parameter names that have been applied as
	 * template params
	 * @param includeQueryStringDelimiter true if the query string should start
	 * with a '?' instead of '&'
	 * @return the query string
	 */
	protected String createQueryString(List<Param> params, Set<String> usedParams, boolean includeQueryStringDelimiter)
			throws JspException {

		return super.createQueryString(params, usedParams, includeQueryStringDelimiter);
	}
	
	/**
	 * Replace template markers in the URL matching available parameters. The
	 * name of matched parameters are added to the used parameters set.
	 * <p>Parameter values are URL encoded.
	 * @param uri the URL with template parameters to replace
	 * @param params parameters used to replace template markers
	 * @param usedParams set of template parameter names that have been replaced
	 * @return the URL with template parameters replaced
	 */
	protected String replaceUriTemplateParams(String uri, List<Param> params, Set<String> usedParams)
			throws JspException {

		return super.replaceUriTemplateParams(uri, params, usedParams);
	}

	/**
	 * Internal enum that classifies URLs by type.
	 */
	private enum UrlType {
		CONTEXT_RELATIVE, RELATIVE, ABSOLUTE
	}
}