1 files changed, 436 insertions, 0 deletions
diff --git a/velocity-engine-core/src/main/java/org/apache/velocity/runtime/visitor/NodeViewMode.java b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/visitor/NodeViewMode.java
new file mode 100644
index 00000000..baac596d
--- /dev/null
+++ b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/visitor/NodeViewMode.java
@@ -0,0 +1,436 @@
+package org.apache.velocity.runtime.visitor;
+
+/*
+ * 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.
+ */
+
+import org.apache.velocity.runtime.parser.Token;
+import org.apache.velocity.runtime.parser.node.*;
+
+/**
+ * This class is simply a visitor implementation
+ * that traverses the AST, produced by the Velocity
+ * parsing process, and creates a visual structure
+ * of the AST. This is primarily used for
+ * debugging, but it useful for documentation
+ * as well.
+ *
+ * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
+ * @version $Id$
+ */
+public class NodeViewMode extends BaseVisitor
+{
+    private int indent = 0;
+    private boolean showTokens = true;
+
+    /** Indent child nodes to help visually identify
+      *  the structure of the AST.
+      */
+    private String indentString()
+    {
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < indent; ++i)
+        {
+            sb.append("  ");
+        }
+        return sb.toString();
+    }
+
+    /**
+      * Display the type of nodes and optionally the
+      * first token.
+      */
+    private Object showNode(Node node, Object data)
+    {
+        String tokens = "";
+        String special = "";
+        Token t;
+
+        if (showTokens)
+        {
+        	// TODO: Token reference
+            t = node.getFirstToken();
+
+            if (t.specialToken != null && ! t.specialToken.image.startsWith(node.getParser().lineComment()))
+                special = t.specialToken.image;
+
+            tokens = " -> " + special + t.image;
+        }
+
+        System.out.println(indentString() + node + tokens);
+        ++indent;
+        data = node.childrenAccept(this, data);
+        --indent;
+        return data;
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.SimpleNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(SimpleNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTprocess, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTprocess node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTExpression, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTExpression node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTAssignment, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTAssignment node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTOrNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTOrNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTAndNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTAndNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTEQNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTEQNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTNENode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTNENode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTLTNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTLTNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTGTNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTGTNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTLENode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTLENode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTGENode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTGENode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTAddNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTAddNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTSubtractNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTSubtractNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTMulNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTMulNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTDivNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTDivNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTModNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTModNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTNotNode, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTNotNode node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTFloatingPointLiteral, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTFloatingPointLiteral node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTIntegerLiteral, java.lang.Object)
+     * @since 1.5
+     */
+    @Override
+    public Object visit(ASTIntegerLiteral node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTStringLiteral, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTStringLiteral node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTIdentifier, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTIdentifier node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTMethod, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTMethod node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTReference, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTReference node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTTrue, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTTrue node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTFalse, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTFalse node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTBlock, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTBlock node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTText, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTText node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTIfStatement, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTIfStatement node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTElseStatement, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTElseStatement node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTElseIfStatement, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTElseIfStatement node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTObjectArray, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTObjectArray node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTDirective, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTDirective node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTWord, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTWord node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTSetDirective, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTSetDirective node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTEscapedDirective, java.lang.Object)
+     * @since 1.5
+     */
+    @Override
+    public Object visit(ASTEscapedDirective node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTEscape, java.lang.Object)
+     * @since 1.5
+     */
+    @Override
+    public Object visit(ASTEscape node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTMap, java.lang.Object)
+     * @since 1.5
+     */
+    @Override
+    public Object visit(ASTMap node, Object data)
+    {
+        return showNode(node,data);
+    }
+
+    /**
+     * @see org.apache.velocity.runtime.visitor.BaseVisitor#visit(org.apache.velocity.runtime.parser.node.ASTIntegerRange, java.lang.Object)
+     */
+    @Override
+    public Object visit(ASTIntegerRange node, Object data)
+    {
+        return showNode(node,data);
+    }
+}