Add support for looking up webapp resources (both core and plugins)

pom.xml

@@ -17,7 +17,9 @@
     <url>https://wiki.jenkins.io/display/JENKINS/Localization+Support+Plugin</url>
 
     <properties>
-        <jenkins.version>2.151-SNAPSHOT</jenkins.version>
+        <jenkins.version>2.164-SNAPSHOT</jenkins.version>
+        <jenkins-core.version>2.164-20190205.211051-1</jenkins-core.version>
+        <jenkins-war.version>2.164-20190205.211156-1</jenkins-war.version>
         <java.level>8</java.level>
     </properties>
 

src/main/java/io/jenkins/plugins/localization/support/LocalizationContributor.java

@@ -95,4 +95,14 @@ public static URL findResource(String resource, Class clazz) {
         // fallback to default: Looking in the class context
         return clazz.getResource(resource);
     }
+
+    /**
+     * Look up a resource for a plugin.
+     *
+     * @param resource the resource to look up
+     * @param plugin the plugin
+     * @return resource for a plugin, or null if not found
+     */
+    @CheckForNull
+    public abstract URL getPluginResource(@Nonnull String resource, @Nonnull PluginWrapper plugin);
 }

src/main/java/io/jenkins/plugins/localization/support/LocalizationMonitor.java

@@ -34,14 +34,12 @@
 import org.kohsuke.accmod.restrictions.NoExternalUse;
 import org.kohsuke.stapler.HttpResponse;
 import org.kohsuke.stapler.StaplerRequest;
-import org.kohsuke.stapler.StaplerResponse;
 import org.kohsuke.stapler.WebApp;
 import org.kohsuke.stapler.interceptor.RequirePOST;
 import org.kohsuke.stapler.jelly.JellyFacet;
 import org.kohsuke.stapler.jelly.ResourceBundleFactory;
 
 import java.io.IOException;
-import java.lang.reflect.Method;
 
 /**
  * This admin monitor ensures that Stapler's JellyFacet uses this plugin's implementation.
@@ -51,8 +49,6 @@
 @Restricted(NoExternalUse.class)
 public class LocalizationMonitor extends AdministrativeMonitor {
 
-    // TODO extend with a check for the Metaclassloader.debugLoader
-
     private PluginWrapper plugin;
 
     @Override

src/main/java/io/jenkins/plugins/localization/support/stapler/LocaleDrivenResourceProviderImpl.java

@@ -0,0 +1,76 @@
+/*
+ * The MIT License
+ *
+ * Copyright (c) 2019 CloudBees, Inc., Daniel Beck
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package io.jenkins.plugins.localization.support.stapler;
+
+import hudson.Extension;
+import hudson.ExtensionList;
+import hudson.PluginWrapper;
+import io.jenkins.plugins.localization.support.LocalizationContributor;
+import jenkins.model.Jenkins;
+import org.kohsuke.stapler.LocaleDrivenResourceProvider;
+
+import javax.annotation.Nonnull;
+import java.net.URL;
+import java.util.logging.Logger;
+
+@Extension
+public class LocaleDrivenResourceProviderImpl extends LocaleDrivenResourceProvider {
+
+    @Override
+    public URL lookup(@Nonnull String path) {
+        PluginWrapper pluginWrapper = findPluginForResourceUrl(path);
+        if (pluginWrapper != null) {
+            path = path.substring(pluginWrapper.baseResourceURL.toString().length());
+            LOGGER.fine("Looking up localized file '" + path + "' from plugin '" + pluginWrapper + "'");
+        } else {
+            LOGGER.fine("Looking up localized file '" + path + "' from webapp");
+        }
+        for (LocalizationContributor contributor : ExtensionList.lookup(LocalizationContributor.class)) {
+            URL url;
+
+            if (pluginWrapper == null) {
+                url = contributor.getResource(path);
+            } else {
+                url = contributor.getPluginResource(path, pluginWrapper);
+            }
+            if (url != null) {
+                LOGGER.fine("Found localized file '" + path + "'");
+                return url;
+            }
+        }
+        LOGGER.fine("Failed to find localized file '" + path + "'");
+        return null;
+    }
+
+    private PluginWrapper findPluginForResourceUrl(String s) {
+        for (PluginWrapper wrapper : Jenkins.get().pluginManager.getPlugins()) {
+            if (s.startsWith(wrapper.baseResourceURL.toString())) {
+                return wrapper;
+            }
+        }
+        return null;
+    }
+
+    private static final Logger LOGGER = Logger.getLogger(LocaleDrivenResourceProviderImpl.class.getName());
+}

src/main/java/io/jenkins/plugins/localization/support/stapler/StaplerManager.java

@@ -27,7 +27,6 @@
 import jenkins.model.Jenkins;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
-import org.kohsuke.stapler.MetaClassLoader;
 import org.kohsuke.stapler.WebApp;
 import org.kohsuke.stapler.jelly.JellyFacet;
 
@@ -40,9 +39,5 @@ public static void initialize() {
         // Override where the Jelly views look for resource bundles
         JellyFacet facet = webApp.getFacet(JellyFacet.class);
         facet.resourceBundleFactory = new ResourceBundleFactoryImpl();
-
-        // Provide a fallback source for resources
-        // TODO restrict to localization plugins only, or perhaps add a dedicated feature to Stapler for this
-        MetaClassLoader.debugLoader = new MetaClassLoader(Jenkins.get().pluginManager.uberClassLoader);
     }
 }