Merge pull request #822 from apache/WW-5379-velocity-stack-alt

WW-5379 Implement alternative mechanism for Velocity directives to obtain ValueStack

core/src/main/java/org/apache/struts2/util/ValueStackProvider.java

@@ -0,0 +1,30 @@
+/*
+ * 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.struts2.util;
+
+import com.opensymphony.xwork2.util.ValueStack;
+
+/**
+ * @since 6.4.0
+ */
+public interface ValueStackProvider {
+
+    ValueStack getValueStack();
+
+}

plugins/velocity/src/main/java/org/apache/struts2/views/velocity/StrutsVelocityContext.java

@@ -19,6 +19,7 @@
 package org.apache.struts2.views.velocity;
 
 import com.opensymphony.xwork2.util.ValueStack;
+import org.apache.struts2.util.ValueStackProvider;
 import org.apache.velocity.VelocityContext;
 
 import java.util.ArrayList;
@@ -26,7 +27,7 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.function.Function;
 
-public class StrutsVelocityContext extends VelocityContext {
+public class StrutsVelocityContext extends VelocityContext implements ValueStackProvider {
 
     private final ValueStack stack;
     private final List<VelocityContext> chainedContexts;
@@ -77,10 +78,10 @@ public class StrutsVelocityContext extends VelocityContext {
     }
 
     protected List<Function<String, Object>> contextGetterList() {
-        return Arrays.asList(this::superGet, this::chainedContextGet, this::stackGet);
+        return Arrays.asList(this::superInternalGet, this::chainedContextGet, this::stackGet);
     }
 
-    protected Object superGet(String key) {
+    protected Object superInternalGet(String key) {
         return super.internalGet(key);
     }
 
@@ -96,11 +97,16 @@ public class StrutsVelocityContext extends VelocityContext {
             return null;
         }
         for (VelocityContext chainedContext : chainedContexts) {
-            Object val = chainedContext.internalGet(key);
+            Object val = chainedContext.get(key);
             if (val != null) {
                 return val;
             }
         }
         return null;
     }
+
+    @Override
+    public ValueStack getValueStack() {
+        return stack;
+    }
 }

plugins/velocity/src/main/java/org/apache/struts2/views/velocity/components/AbstractDirective.java

@@ -18,26 +18,28 @@
  */
 package org.apache.struts2.views.velocity.components;
 
-import java.io.IOException;
-import java.io.Writer;
-import java.util.HashMap;
-import java.util.Map;
-
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
-
+import com.opensymphony.xwork2.inject.Container;
+import com.opensymphony.xwork2.util.ValueStack;
 import org.apache.struts2.ServletActionContext;
 import org.apache.struts2.components.Component;
+import org.apache.struts2.util.ValueStackProvider;
+import org.apache.struts2.views.util.ContextUtil;
+import org.apache.velocity.context.AbstractContext;
+import org.apache.velocity.context.Context;
 import org.apache.velocity.context.InternalContextAdapter;
+import org.apache.velocity.context.InternalWrapperContext;
 import org.apache.velocity.exception.MethodInvocationException;
 import org.apache.velocity.exception.ParseErrorException;
 import org.apache.velocity.exception.ResourceNotFoundException;
 import org.apache.velocity.runtime.directive.Directive;
 import org.apache.velocity.runtime.parser.node.Node;
 
-import com.opensymphony.xwork2.ActionContext;
-import com.opensymphony.xwork2.inject.Container;
-import com.opensymphony.xwork2.util.ValueStack;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.io.Writer;
+import java.util.HashMap;
+import java.util.Map;
 
 public abstract class AbstractDirective extends Directive {
     public String getName() {
@@ -57,8 +59,11 @@ public abstract class AbstractDirective extends Directive {
     protected abstract Component getBean(ValueStack stack, HttpServletRequest req, HttpServletResponse res);
 
     public boolean render(InternalContextAdapter ctx, Writer writer, Node node) throws IOException, ResourceNotFoundException, ParseErrorException, MethodInvocationException {
-        // get the bean
-        ValueStack stack = (ValueStack) ctx.get("stack");
+        ValueStack stack = extractValueStack(ctx);
+        if (stack == null) {
+            // Fallback to assuming the ValueStack was put into the Velocity context (as is by default)
+            stack = (ValueStack) ctx.get(ContextUtil.STACK);
+        }
         HttpServletRequest req = (HttpServletRequest) stack.getContext().get(ServletActionContext.HTTP_REQUEST);
         HttpServletResponse res = (HttpServletResponse) stack.getContext().get(ServletActionContext.HTTP_RESPONSE);
         Component bean = getBean(stack, req, res);
@@ -79,6 +84,27 @@ public abstract class AbstractDirective extends Directive {
         return true;
     }
 
+    private ValueStack extractValueStack(Context context) {
+        do {
+            if (context instanceof ValueStackProvider) {
+                return ((ValueStackProvider) context).getValueStack();
+            }
+            context = extractContext(context);
+        } while (context != null);
+
+        return null;
+    }
+
+    private Context extractContext(Context context) {
+        if (context instanceof InternalWrapperContext) {
+            return ((InternalWrapperContext) context).getInternalUserContext();
+        }
+        if (context instanceof AbstractContext) {
+            return ((AbstractContext) context).getChainedContext();
+        }
+        return null;
+    }
+
     /**
      * <p>
      * Create a Map of properties that the user has passed in. For example:

plugins/velocity/src/test/java/org/apache/struts2/views/velocity/StrutsVelocityContextTest.java

@@ -54,7 +54,7 @@ public class StrutsVelocityContextTest {
 
     @Test
     public void getChainedValue() {
-        when(chainedContext.internalGet("foo")).thenReturn("bar");
+        when(chainedContext.get("foo")).thenReturn("bar");
         assertEquals("bar", strutsVelocityContext.internalGet("foo"));
     }
 
@@ -75,7 +75,7 @@ public class StrutsVelocityContextTest {
         when(stack.findValue("foo")).thenReturn("qux");
         assertEquals("qux", strutsVelocityContext.internalGet("foo"));
 
-        when(chainedContext.internalGet("foo")).thenReturn("baz");
+        when(chainedContext.get("foo")).thenReturn("baz");
         assertEquals("baz", strutsVelocityContext.internalGet("foo"));
 
         strutsVelocityContext.put("foo", "bar");