Github user klopfdreh commented on a diff in the pull request:
https://github.com/apache/wicket/pull/87#discussion_r24098307
--- Diff:
wicket-core/src/main/java/org/apache/wicket/resource/CssUrlReplacementCompressor.java
---
@@ -0,0 +1,144 @@
+/*
+ * 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.wicket.resource;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.net.URL;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.apache.wicket.Application;
+import org.apache.wicket.Component;
+import org.apache.wicket.Page;
+import org.apache.wicket.WicketRuntimeException;
+import org.apache.wicket.application.IComponentInitializationListener;
+import org.apache.wicket.css.ICssCompressor;
+import org.apache.wicket.request.cycle.RequestCycle;
+import org.apache.wicket.request.resource.PackageResourceReference;
+
+/**
+ * This compressor is used to replace url within css files with resources
that belongs to their
+ * corresponding page classes. The compress method is not compressing any
content, but replacing the
+ * URLs with Wicket representatives.<br>
+ * <br>
+ * Usage:
+ *
+ * <pre>
+ * this.getResourceSettings().setCssCompressor(new
CssUrlReplacementCompressor(this));
+ * </pre>
+ *
+ * @since 6.20.0
+ * @author Tobias Soloschenko
+ *
+ */
+public class CssUrlReplacementCompressor implements ICssCompressor
+{
+
+ // Holds the names of pages
+ private Map<String, String> pageNames = Collections.synchronizedMap(new
LinkedHashMap<String, String>());
+
+ // The pattern to find URLs in CSS resources
+ private Pattern urlPattern =
Pattern.compile("url\\(['|\"](.*)['|\"]\\)");
+
+ public CssUrlReplacementCompressor(Application application)
+ {
+
+ // Create an instantiation listener which filters only pages.
+ application.getComponentInitializationListeners().add(
+ new IComponentInitializationListener()
+ {
+
+ @Override
+ public void onInitialize(Component component)
+ {
+ if
(Page.class.isAssignableFrom(component.getClass()))
+ {
+
CssUrlReplacementCompressor.this.pageNames.put(component.getClass()
+ .getName(),
component.getClass().getSimpleName());
+ }
+ }
+ });
+ }
+
+ /**
+ * Replaces the URLs of CSS resources with Wicket representatives.
+ */
+ @SuppressWarnings("unchecked")
+ @Override
+ public String compress(String original)
+ {
+ Matcher matcher = this.urlPattern.matcher(original);
+ // Search for urls
+ while (matcher.find())
+ {
+ Collection<String> pageNames = this.pageNames.keySet();
+ for (String pageName : pageNames)
+ {
+ try
+ {
+ Class<Page> pageClass =
(Class<Page>)Class.forName(pageName);
+ String url = matcher.group(1);
+ if (!url.contains("/"))
+ {
+ URL urlResource =
pageClass.getResource(url);
--- End diff --
Mhh, the problem here is that you can use any scope in
PackageResourceReferences, even classes which are not the components that use
the image. In this case it is hard to find a generic way to get those images.
What we could do is let away the check of pages so that the images of panels
could also be found.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
