Introduced a plugin-API and show usage with rhino-xml

rhino-xml/src/main/java/module-info.java

@@ -1,9 +1,9 @@
 module org.mozilla.javascript.xml {
     exports org.mozilla.javascript.xmlimpl;
 
-    provides org.mozilla.javascript.xml.XMLLoader with
-            org.mozilla.javascript.xmlimpl.XMLLoaderImpl;
-
     requires transitive org.mozilla.rhino;
     requires transitive java.xml;
+
+    provides org.mozilla.javascript.Plugin with
+            org.mozilla.javascript.xmlimpl.XmlPlugin;
 }

rhino-xml/src/main/java/org/mozilla/javascript/xmlimpl/XmlPlugin.java

@@ -0,0 +1,43 @@
+package org.mozilla.javascript.xmlimpl;
+
+import org.mozilla.javascript.CompilerEnvirons;
+import org.mozilla.javascript.Context;
+import org.mozilla.javascript.LazilyLoadedCtor;
+import org.mozilla.javascript.Plugin;
+import org.mozilla.javascript.ScriptableObject;
+
+/**
+ * Registers the XML objects in the scope.
+ *
+ * @author Roland Praml, Foconis Analytics GmbH
+ */
+public class XmlPlugin implements Plugin {
+
+    @Override
+    public String getName() {
+        return "xml";
+    }
+
+    @Override
+    public boolean isSafe() {
+        return true;
+    }
+
+    @Override
+    public void init(Context cx, ScriptableObject scope, boolean sealed) {
+        if (cx.hasFeature(Context.FEATURE_E4X)) {
+            String xmlImpl = XMLLibImpl.class.getName();
+            new LazilyLoadedCtor(scope, "XML", xmlImpl, sealed, true);
+            new LazilyLoadedCtor(scope, "XMLList", xmlImpl, sealed, true);
+            new LazilyLoadedCtor(scope, "Namespace", xmlImpl, sealed, true);
+            new LazilyLoadedCtor(scope, "QName", xmlImpl, sealed, true);
+        }
+    }
+
+    @Override
+    public void initCompilerEnvirons(Context cx, CompilerEnvirons compilerEnvirons) {
+        if (cx.hasFeature(Context.FEATURE_E4X)) {
+            compilerEnvirons.setXmlAvailable(true);
+        }
+    }
+}

rhino-xml/src/main/resources/META-INF/services/org.mozilla.javascript.Plugin

@@ -0,0 +1 @@
+org.mozilla.javascript.xmlimpl.XmlPlugin

rhino-xml/src/test/java/org/mozilla/javascript/tests/XMLPresentTest.java

@@ -0,0 +1,32 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.javascript.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.Test;
+import org.mozilla.javascript.Context;
+import org.mozilla.javascript.ContextFactory;
+import org.mozilla.javascript.Scriptable;
+
+/**
+ * Test if XML is present. This test exists in "rhino-xml" where XML is present and in "rhino",
+ * where XML is not on classpath.
+ *
+ * @author Roland Praml
+ */
+public class XMLPresentTest {
+
+    @Test
+    public void testXMLPresent() {
+        try (Context cx = ContextFactory.getGlobal().enterContext()) {
+            Scriptable scope = cx.initStandardObjects();
+            Object result =
+                    cx.evaluateString(
+                            scope, "new XML('<a></a>').toXMLString();", "source", 1, null);
+            assertEquals("<a/>", Context.toString(result));
+        }
+    }
+}

rhino/src/main/java/module-info.java

@@ -14,7 +14,7 @@
     exports org.mozilla.javascript.xml;
 
     uses org.mozilla.javascript.RegExpProxy;
-    uses org.mozilla.javascript.xml.XMLLoader;
+    uses org.mozilla.javascript.Plugin;
 
     provides org.mozilla.javascript.RegExpProxy with
             org.mozilla.javascript.regexp.RegExpImpl;

rhino/src/main/java/org/mozilla/javascript/CompilerEnvirons.java

@@ -33,7 +33,6 @@ public void initFromContext(Context cx) {
         allowMemberExprAsFunctionName = cx.hasFeature(Context.FEATURE_MEMBER_EXPR_AS_FUNCTION_NAME);
         strictMode = cx.hasFeature(Context.FEATURE_STRICT_MODE);
         warningAsError = cx.hasFeature(Context.FEATURE_WARNING_AS_ERROR);
-        xmlAvailable = cx.hasFeature(Context.FEATURE_E4X);
 
         interpretedMode = cx.isInterpretedMode();
 
@@ -42,6 +41,7 @@ public void initFromContext(Context cx) {
 
         // Observer code generation in compiled code :
         generateObserverCount = cx.isGenerateObserverCount();
+        cx.getFactory().getPlugins().forEach(plugin -> plugin.initCompilerEnvirons(cx, this));
     }
 
     public final ErrorReporter getErrorReporter() {

rhino/src/main/java/org/mozilla/javascript/Context.java

@@ -35,7 +35,6 @@
 import org.mozilla.javascript.debug.DebuggableScript;
 import org.mozilla.javascript.debug.Debugger;
 import org.mozilla.javascript.xml.XMLLib;
-import org.mozilla.javascript.xml.XMLLoader;
 
 /**
  * This class represents the runtime context of an executing script.
@@ -199,7 +198,8 @@ public class Context implements Closeable {
 
     /**
      * Control if support for E4X(ECMAScript for XML) extension is available. If
-     * hasFeature(FEATURE_E4X) returns true, the XML syntax is available.
+     * hasFeature(FEATURE_E4X) returns true and rhino-xml is on classpath, the XML syntax is
+     * available.
      *
      * <p>By default {@link #hasFeature(int)} returns true if the current JS version is set to
      * {@link #VERSION_DEFAULT} or is at least {@link #VERSION_1_6}.
@@ -2327,11 +2327,8 @@ public boolean hasFeature(int featureIndex) {
      */
     @Deprecated
     public XMLLib.Factory getE4xImplementationFactory() {
-        XMLLoader loader = ScriptRuntime.loadOneServiceImplementation(XMLLoader.class);
-        if (loader != null) {
-            return loader.getFactory();
-        }
-        return null;
+        throw new UnsupportedOperationException(
+                "getE4xImplementationFactory is no longer supported");
     }
 
     /**

rhino/src/main/java/org/mozilla/javascript/ContextFactory.java

@@ -10,6 +10,10 @@
 
 import java.security.AccessController;
 import java.security.PrivilegedAction;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.ServiceLoader;
 
 /**
  * Factory class that Rhino runtime uses to create new {@link Context} instances. A <code>
@@ -114,6 +118,26 @@ public class ContextFactory {
     private volatile Object listeners;
     private boolean disabledListening;
     private ClassLoader applicationClassLoader;
+    private final List<Plugin> plugins;
+
+    /** returns a list of plugins found by the ServiceLoader */
+    public static List<Plugin> getDefaultPluginsFromServiceLoader() {
+        List<Plugin> result = new ArrayList<Plugin>();
+        ServiceLoader.load(Plugin.class)
+                .forEach(
+                        plugin -> {
+                            // TODO: use RhinoConfig here!
+                            String disabled =
+                                    SecurityUtilities.getSystemProperty(
+                                            "rhino.plugin." + plugin.getName() + ".disabled");
+                            if ("1".equals(disabled) || "true".equals(disabled)) {
+                                // the plugin is disabled
+                            } else {
+                                result.add(plugin);
+                            }
+                        });
+        return result;
+    }
 
     /** Listener of {@link Context} creation and release events. */
     public interface Listener {
@@ -127,6 +151,16 @@ public interface Listener {
         public void contextReleased(Context cx);
     }
 
+    /** Constructs a new ContextFactory with the plugins found by serviceLoader. */
+    public ContextFactory() {
+        this(getDefaultPluginsFromServiceLoader());
+    }
+
+    /** Constructs a new ContextFactory with a given list of plugins. */
+    public ContextFactory(List<Plugin> plugins) {
+        this.plugins = Collections.unmodifiableList(plugins);
+    }
+
     /**
      * Get global ContextFactory.
      *
@@ -516,4 +550,9 @@ public final void exit() {
     public final Context enterContext(Context cx) {
         return Context.enter(cx, this);
     }
+
+    /** Returns a list of plugins. */
+    public List<Plugin> getPlugins() {
+        return plugins;
+    }
 }

rhino/src/main/java/org/mozilla/javascript/Plugin.java

@@ -0,0 +1,26 @@
+package org.mozilla.javascript;
+
+/**
+ * Plugins may be loaded with the serviceLocator.
+ *
+ * @author Roland Praml, Foconis Analytics GmbH
+ */
+public interface Plugin {
+
+    /**
+     * defines, if this plugin should be initialized in safe standard objects or only in standard
+     * objects
+     */
+    default boolean isSafe() {
+        return false;
+    }
+
+    /** The name of the plugin. */
+    String getName();
+
+    /** Initializes the safe standard objects. */
+    default void init(Context cx, ScriptableObject scope, boolean sealed) {}
+
+    /** Initialize the compiler environmnt. */
+    default void initCompilerEnvirons(Context cx, CompilerEnvirons compilerEnvirons) {}
+}

rhino/src/main/java/org/mozilla/javascript/ScriptRuntime.java

@@ -25,7 +25,6 @@
 import org.mozilla.javascript.v8dtoa.DoubleConversion;
 import org.mozilla.javascript.v8dtoa.FastDtoa;
 import org.mozilla.javascript.xml.XMLLib;
-import org.mozilla.javascript.xml.XMLLoader;
 import org.mozilla.javascript.xml.XMLObject;
 
 /**
@@ -201,10 +200,9 @@ public static ScriptableObject initSafeStandardObjects(
         new LazilyLoadedCtor(
                 scope, "Continuation", "org.mozilla.javascript.NativeContinuation", sealed, true);
 
-        if (cx.hasFeature(Context.FEATURE_E4X)) {
-            XMLLoader loader = loadOneServiceImplementation(XMLLoader.class);
-            if (loader != null) {
-                loader.load(scope, sealed);
+        for (Plugin plugin : cx.getFactory().getPlugins()) {
+            if (plugin.isSafe()) {
+                plugin.init(cx, scope, sealed);
             }
         }
 
@@ -312,6 +310,11 @@ public static ScriptableObject initStandardObjects(
             Context cx, ScriptableObject scope, boolean sealed) {
         ScriptableObject s = initSafeStandardObjects(cx, scope, sealed);
 
+        for (Plugin plugin : cx.getFactory().getPlugins()) {
+            if (!plugin.isSafe()) {
+                plugin.init(cx, scope, sealed);
+            }
+        }
         new LazilyLoadedCtor(
                 s, "Packages", "org.mozilla.javascript.NativeJavaTopPackage", sealed, true);
         new LazilyLoadedCtor(

rhino/src/main/java/org/mozilla/javascript/xml/XMLLib.java

@@ -22,18 +22,11 @@ public abstract class XMLLib {
      * flexible) to write an interface that returns an XMLLib object rather than a class name, for
      * example. But that would cause many more ripple effects in the code, all the way back to
      * {@link ScriptRuntime}.
+     *
+     * @deprecated required for Context.getE4xImplementationFactory().
      */
+    @Deprecated
     public abstract static class Factory {
-
-        public static Factory create(final String className) {
-            return new Factory() {
-                @Override
-                public String getImplementationClassName() {
-                    return className;
-                }
-            };
-        }
-
         public abstract String getImplementationClassName();
     }
 

rhino/src/test/java/org/mozilla/javascript/tests/XMLPresentTest.java

@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.javascript.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.fail;
+
+import org.junit.Test;
+import org.mozilla.javascript.Context;
+import org.mozilla.javascript.ContextFactory;
+import org.mozilla.javascript.EcmaError;
+import org.mozilla.javascript.Scriptable;
+
+/**
+ * Test if XML is present. This test exists in "rhino-xml" where XML is present and in "rhino",
+ * where XML is not on classpath.
+ *
+ * @author Roland Praml
+ */
+public class XMLPresentTest {
+
+    @Test
+    public void testXMLPresent() {
+        try (Context cx = ContextFactory.getGlobal().enterContext()) {
+            Scriptable scope = cx.initStandardObjects();
+            Object result =
+                    cx.evaluateString(
+                            scope, "new XML('<a></a>').toXMLString();", "source", 1, null);
+            fail("not expected");
+        } catch (EcmaError e) {
+            assertEquals("ReferenceError: \"XML\" is not defined. (source#1)", e.getMessage());
+        }
+    }
+}