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XLT (Xceptance LoadTest) is an extensive load and performance test tool developed and maintained by Xceptance.
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/*
* Copyright (c) 2002-2024 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
* https://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.htmlunit.html;
import static org.htmlunit.BrowserVersionFeatures.CSS_DISPLAY_BLOCK2;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Locale;
import java.util.Map;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.htmlunit.BrowserVersion;
import org.htmlunit.SgmlPage;
import org.htmlunit.WebClient;
import org.htmlunit.WebRequest;
import org.htmlunit.WebResponse;
import org.htmlunit.css.CssStyleSheet;
import org.htmlunit.cssparser.dom.MediaListImpl;
import org.htmlunit.javascript.AbstractJavaScriptEngine;
import org.htmlunit.javascript.PostponedAction;
import org.htmlunit.javascript.host.event.Event;
import org.htmlunit.javascript.host.html.HTMLLinkElement;
import org.htmlunit.util.StringUtils;
import org.htmlunit.xml.XmlPage;
/**
* Wrapper for the HTML element "link". Note: This is not a clickable link,
* that one is an HtmlAnchor
*
* @author Mike Bowler
* @author David K. Taylor
* @author Christian Sell
* @author Ahmed Ashour
* @author Marc Guillemot
* @author Frank Danek
* @author Ronald Brill
*/
public class HtmlLink extends HtmlElement {
private static final Log LOG = LogFactory.getLog(HtmlLink.class);
/** The HTML tag represented by this element. */
public static final String TAG_NAME = "link";
/**
* The associated style sheet (only valid for links of type
* <link rel="stylesheet" type="text/css" href="..." />).
*/
private CssStyleSheet sheet_;
/**
* Creates an instance of HtmlLink
*
* @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 qualifiedName, final SgmlPage page,
final Map attributes) {
super(qualifiedName, page, attributes);
}
/**
* Returns the value of the attribute {@code charset}. Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute {@code charset}
* or an empty string if that attribute isn't defined.
*/
public final String getCharsetAttribute() {
return getAttributeDirect("charset");
}
/**
* Returns the value of the attribute {@code href}. Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute {@code href}
* or an empty string if that attribute isn't defined.
*/
public final String getHrefAttribute() {
return getAttributeDirect("href");
}
/**
* Returns the value of the attribute {@code hreflang}. Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute {@code hreflang}
* or an empty string if that attribute isn't defined.
*/
public final String getHrefLangAttribute() {
return getAttributeDirect("hreflang");
}
/**
* Returns the value of the attribute {@code type}. Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute {@code type}
* or an empty string if that attribute isn't defined.
*/
public final String getTypeAttribute() {
return getAttributeDirect(TYPE_ATTRIBUTE);
}
/**
* Returns the value of the attribute {@code rel}. Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute {@code rel}
* or an empty string if that attribute isn't defined.
*/
public final String getRelAttribute() {
return getAttributeDirect("rel");
}
/**
* Returns the value of the attribute {@code rev}. Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute {@code rev}
* or an empty string if that attribute isn't defined.
*/
public final String getRevAttribute() {
return getAttributeDirect("rev");
}
/**
* Returns the value of the attribute {@code media}. Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute {@code media}
* or an empty string if that attribute isn't defined.
*/
public final String getMediaAttribute() {
return getAttributeDirect("media");
}
/**
* Returns the value of the attribute {@code target}. Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute {@code target}
* or an empty string if that attribute isn't defined.
*/
public final String getTargetAttribute() {
return getAttributeDirect("target");
}
/**
* POTENIAL PERFORMANCE KILLER - DOWNLOADS THE RESOURCE - USE AT YOUR OWN RISK.
* If the linked content is not already downloaded it triggers a download. Then it stores the response
* for later use.
*
* @param downloadIfNeeded indicates if a request should be performed this hasn't been done previously
* @return {@code null} 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 {
return getWebResponse(downloadIfNeeded, null);
}
/**
* INTERNAL API - SUBJECT TO CHANGE AT ANY TIME - USE AT YOUR OWN RISK.
*
* If the linked content is not already downloaded it triggers a download. Then it stores the response
* for later use.
*
* @param downloadIfNeeded indicates if a request should be performed this hasn't been done previously
* @param request the request; if null getWebRequest() is called to create one
* @return {@code null} 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, WebRequest request) throws IOException {
final WebClient webclient = getPage().getWebClient();
if (null == request) {
request = getWebRequest();
}
if (downloadIfNeeded) {
try {
final WebResponse response = webclient.loadWebResponse(request);
if (response.isSuccess()) {
executeEvent(Event.TYPE_LOAD);
}
else {
executeEvent(Event.TYPE_ERROR);
}
return response;
}
catch (final IOException e) {
executeEvent(Event.TYPE_ERROR);
throw e;
}
}
// retrieve the response, from the cache if available
return webclient.getCache().getCachedResponse(request);
}
/**
* Returns the request which will allow us to retrieve the content referenced by the {@code href} attribute.
* @return the request which will allow us to retrieve the content referenced by the {@code href} attribute
* @throws MalformedURLException in case of problem resolving the URL
*/
public WebRequest getWebRequest() throws MalformedURLException {
final HtmlPage page = (HtmlPage) getPage();
final URL url = page.getFullyQualifiedUrl(getHrefAttribute());
final BrowserVersion browser = page.getWebClient().getBrowserVersion();
final WebRequest request = new WebRequest(url, browser.getCssAcceptHeader(), browser.getAcceptEncodingHeader());
// use the page encoding even if this is a GET requests
request.setCharset(page.getCharset());
request.setRefererlHeader(page.getUrl());
return request;
}
/**
* {@inheritDoc}
*/
@Override
public DisplayStyle getDefaultStyleDisplay() {
if (hasFeature(CSS_DISPLAY_BLOCK2)) {
return DisplayStyle.NONE;
}
return DisplayStyle.INLINE;
}
/**
* {@inheritDoc}
*/
@Override
public boolean mayBeDisplayed() {
return false;
}
private void executeEvent(final String type) {
final HTMLLinkElement link = getScriptableObject();
final Event event = new Event(this, type);
link.executeEventLocally(event);
}
/**
* {@inheritDoc}
*/
@Override
public void onAllChildrenAddedToPage(final boolean postponed) {
if (getOwnerDocument() instanceof XmlPage) {
return;
}
if (LOG.isDebugEnabled()) {
LOG.debug("Link node added: " + asXml());
}
if (!isStyleSheetLink()) {
if (LOG.isDebugEnabled()) {
LOG.debug("Link type '" + getRelAttribute() + "' not supported ("
+ asXml().replaceAll("[\\r\\n]", "") + ").");
}
return;
}
final WebClient webClient = getPage().getWebClient();
if (!webClient.getOptions().isCssEnabled()) {
if (LOG.isDebugEnabled()) {
LOG.debug("Stylesheet Link found but ignored because css support is disabled ("
+ asXml().replaceAll("[\\r\\n]", "") + ").");
}
return;
}
if (!webClient.isJavaScriptEngineEnabled()) {
if (LOG.isDebugEnabled()) {
LOG.debug("Stylesheet Link found but ignored because javascript engine is disabled ("
+ asXml().replaceAll("[\\r\\n]", "") + ").");
}
return;
}
final PostponedAction action = new PostponedAction(getPage(), "Loading of link " + this) {
@Override
public void execute() {
final HTMLLinkElement linkElem = HtmlLink.this.getScriptableObject();
// force loading, caching inside the link
linkElem.getSheet();
}
};
final AbstractJavaScriptEngine engine = webClient.getJavaScriptEngine();
if (postponed) {
engine.addPostponedAction(action);
}
else {
try {
action.execute();
}
catch (final RuntimeException e) {
throw e;
}
catch (final Exception e) {
throw new RuntimeException(e);
}
}
}
/**
* Returns the associated style sheet (only valid for links of type
* <link rel="stylesheet" type="text/css" href="..." />).
* @return the associated style sheet
*/
public CssStyleSheet getSheet() {
if (sheet_ == null) {
sheet_ = CssStyleSheet.loadStylesheet(this, this, null);
}
return sheet_;
}
/**
* @return true if the rel attribute is 'stylesheet'
*/
public boolean isStyleSheetLink() {
String rel = getRelAttribute();
if (rel != null) {
rel = rel.toLowerCase(Locale.ROOT);
return ArrayUtils.contains(StringUtils.splitAtBlank(rel), "stylesheet");
}
return false;
}
/**
* Experimental API: May be changed in next release
* and may not yet work perfectly!
*
* Verifies if the provided node is a link node pointing to an active stylesheet.
*
* @return true if the provided node is a stylesheet link
*/
public boolean isActiveStyleSheetLink() {
if (isStyleSheetLink()) {
final String media = getMediaAttribute();
if (org.apache.commons.lang3.StringUtils.isBlank(media)) {
return true;
}
final MediaListImpl mediaList =
CssStyleSheet.parseMedia(media, getPage().getWebClient());
return CssStyleSheet.isActive(mediaList, getPage().getEnclosingWindow());
}
return false;
}
}