/*
* Copyright (c) 2002-2010 Gargoyle Software Inc.
*
* 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 com.gargoylesoftware.htmlunit.html;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Map;
import com.gargoylesoftware.htmlunit.SgmlPage;
import com.gargoylesoftware.htmlunit.WebClient;
import com.gargoylesoftware.htmlunit.WebRequestSettings;
import com.gargoylesoftware.htmlunit.WebResponse;
/**
* Wrapper for the HTML element "link". <b>Note:</b> This is not a clickable link,
* that one is an HtmlAnchor
*
* @version $Revision: 5301 $
* @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
* @author David K. Taylor
* @author <a href="mailto:cse@dynabean.de">Christian Sell</a>
* @author Ahmed Ashour
* @author Marc Guillemot
*/
public class HtmlLink extends HtmlElement {
private static final long serialVersionUID = 323745155296983364L;
/** The HTML tag represented by this element. */
public static final String TAG_NAME = "link";
private WebResponse cachedWebResponse_;
/**
* Creates an instance of HtmlLink
*
* @param namespaceURI the URI that identifies an XML namespace
* @param qualifiedName the qualified name of the element type to instantiate
* @param page the HtmlPage that contains this element
* @param attributes the initial attributes
*/
HtmlLink(final String namespaceURI, final String qualifiedName, final SgmlPage page,
final Map<String, DomAttr> attributes) {
super(namespaceURI, qualifiedName, page, attributes);
}
/**
* Returns the value of the attribute "charset". Refer to the
* <a href='http://www.w3.org/TR/html401/'>HTML 4.01</a>
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "charset"
* or an empty string if that attribute isn't defined.
*/
public final String getCharsetAttribute() {
return getAttribute("charset");
}
/**
* Returns the value of the attribute "href". Refer to the
* <a href='http://www.w3.org/TR/html401/'>HTML 4.01</a>
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "href"
* or an empty string if that attribute isn't defined.
*/
public final String getHrefAttribute() {
return getAttribute("href");
}
/**
* Returns the value of the attribute "hreflang". Refer to the
* <a href='http://www.w3.org/TR/html401/'>HTML 4.01</a>
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "hreflang"
* or an empty string if that attribute isn't defined.
*/
public final String getHrefLangAttribute() {
return getAttribute("hreflang");
}
/**
* Returns the value of the attribute "type". Refer to the
* <a href='http://www.w3.org/TR/html401/'>HTML 4.01</a>
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "type"
* or an empty string if that attribute isn't defined.
*/
public final String getTypeAttribute() {
return getAttribute("type");
}
/**
* Returns the value of the attribute "rel". Refer to the
* <a href='http://www.w3.org/TR/html401/'>HTML 4.01</a>
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "rel"
* or an empty string if that attribute isn't defined.
*/
public final String getRelAttribute() {
return getAttribute("rel");
}
/**
* Returns the value of the attribute "rev". Refer to the
* <a href='http://www.w3.org/TR/html401/'>HTML 4.01</a>
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "rev"
* or an empty string if that attribute isn't defined.
*/
public final String getRevAttribute() {
return getAttribute("rev");
}
/**
* Returns the value of the attribute "media". Refer to the
* <a href='http://www.w3.org/TR/html401/'>HTML 4.01</a>
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "media"
* or an empty string if that attribute isn't defined.
*/
public final String getMediaAttribute() {
return getAttribute("media");
}
/**
* Returns the value of the attribute "target". Refer to the
* <a href='http://www.w3.org/TR/html401/'>HTML 4.01</a>
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "target"
* or an empty string if that attribute isn't defined.
*/
public final String getTargetAttribute() {
return getAttribute("target");
}
/**
* <span style="color:red">POTENIAL PERFORMANCE KILLER - DOWNLOADS THE RESOURCE - USE AT YOUR OWN RISK.</span><br/>
* If the linked content is not already downloaded it triggers a download. Then it stores the response
* for later use.<br/>
*
* @param downloadIfNeeded indicates if a request should be performed this hasn't been done previously
* @return <code>null</code> if no download should be performed and when this wasn't already done; the response
* received when performing a request for the content referenced by this tag otherwise
* @throws IOException if an error occurs while downloading the content
*/
public WebResponse getWebResponse(final boolean downloadIfNeeded) throws IOException {
if (downloadIfNeeded && cachedWebResponse_ == null) {
final WebClient webclient = getPage().getWebClient();
cachedWebResponse_ = webclient.loadWebResponse(getWebRequestSettings());
}
return cachedWebResponse_;
}
/**
* Returns the request settings which will allow us to retrieve the content referenced by the "href" attribute.
* @return the request settings which will allow us to retrieve the content referenced by the "href" attribute
* @throws MalformedURLException in case of problem resolving the URL
*/
public WebRequestSettings getWebRequestSettings() throws MalformedURLException {
final HtmlPage page = (HtmlPage) getPage();
final URL url = page.getFullyQualifiedUrl(getHrefAttribute());
final WebRequestSettings request = new WebRequestSettings(url);
request.setAdditionalHeader("Referer", page.getWebResponse().getRequestSettings().getUrl().toExternalForm());
return request;
}
}