Index: src/java/main/org/apache/maven/jelly/tags/maven/MavenTag.java
===================================================================
RCS file: /home/cvspublic/maven-jelly-tags/src/java/main/org/apache/maven/jelly/tags/maven/Attic/MavenTag.java,v
retrieving revision 1.14
diff -u -r1.14 MavenTag.java
--- src/java/main/org/apache/maven/jelly/tags/maven/MavenTag.java	5 May 2004 13:05:51 -0000	1.14
+++ src/java/main/org/apache/maven/jelly/tags/maven/MavenTag.java	7 Dec 2004 15:16:46 -0000
@@ -28,7 +28,9 @@
 import java.io.File;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  * A way of running maven as a Jelly tag
@@ -51,6 +53,9 @@
 
     /** whether to ignore exceptions */
     private boolean ignoreFailures;
+    
+    /** map of context variables */
+    private Map contextVariableMap = new HashMap();
 
     /**
      * Process the tag. Set up a new maven instance with the same maven home
@@ -65,6 +70,9 @@
     {
         checkAttribute( getDescriptor(), "descriptor" );
 
+        clearContextVariables();
+        invokeBody(output);
+        
         Project project = null;
         try
         {
@@ -79,7 +87,7 @@
                 goalList.addAll( MavenUtils.getGoalListFromCsv( getGoals() ) );
             }
 
-            getMavenContext().getMavenSession().attainGoals( project, goalList );
+            attainGoals( project, goalList );
         }
         catch ( Exception e )
         {
@@ -103,6 +111,35 @@
         }
     }
 
+    /**
+     * Clears the map of context variables held for this tag
+     */
+    public final void clearContextVariables() {
+        contextVariableMap.clear();
+    }
+
+    /**
+     * Puts the supplied context variable into the map
+     * @param name the name of the variable
+     * @param value the value of the variable
+     */
+    public final void putContextVariable(String name, Object value) {
+        contextVariableMap.put(name, value);
+    }
+
+    /**
+     * Attains the supplied list of goals on the supplied project
+     * @param project the project to use
+     * @param goalList the goals to attain
+     * @throws Exception
+     * @todo don't throw exception
+     */
+    public final void attainGoals(Project project, List goalList) 
+            throws Exception {
+        getMavenContext().getMavenSession().attainGoals( project, goalList, 
+                contextVariableMap );
+    }
+    
     // ------------------------------------------------------------
     // A C C E S S O R S
     // ------------------------------------------------------------
Index: src/java/main/org/apache/maven/jelly/tags/maven/MavenTagLibrary.java
===================================================================
RCS file: /home/cvspublic/maven-jelly-tags/src/java/main/org/apache/maven/jelly/tags/maven/Attic/MavenTagLibrary.java,v
retrieving revision 1.16
diff -u -r1.16 MavenTagLibrary.java
--- src/java/main/org/apache/maven/jelly/tags/maven/MavenTagLibrary.java	5 May 2004 13:05:51 -0000	1.16
+++ src/java/main/org/apache/maven/jelly/tags/maven/MavenTagLibrary.java	7 Dec 2004 15:16:47 -0000
@@ -40,6 +40,7 @@
         registerTag( "maven", MavenTag.class );
         registerTag( "pom", PomTag.class );
         registerTag( "reactor", ReactorTag.class );
+        registerTag( "contextVariable", ContextVariableTag.class);
         registerTag( "concat", ConcatTag.class );
         registerTag( "input", InputTag.class );
         registerTag( "makeAbsolutePath", MakeAbsolutePathTag.class );
Index: src/java/main/org/apache/maven/jelly/tags/maven/ReactorTag.java
===================================================================
RCS file: /home/cvspublic/maven-jelly-tags/src/java/main/org/apache/maven/jelly/tags/maven/Attic/ReactorTag.java,v
retrieving revision 1.40.2.1
diff -u -r1.40.2.1 ReactorTag.java
--- src/java/main/org/apache/maven/jelly/tags/maven/ReactorTag.java	6 Nov 2004 07:26:33 -0000	1.40.2.1
+++ src/java/main/org/apache/maven/jelly/tags/maven/ReactorTag.java	7 Dec 2004 15:17:03 -0000
@@ -313,6 +313,9 @@
             throw new MissingAttributeException( "glob|includes|projectList" );
         }
 
+        clearContextVariables();
+        invokeBody(output);
+        
         log.info( "Starting the reactor..." );
 
         List sortedProjects = null;
@@ -365,7 +368,7 @@
             {
                 if ( !collectOnly )
                 {
-                    getMavenContext().getMavenSession().attainGoals( project, goalList );
+                    attainGoals( project, goalList );
                 }
             }
             catch ( Exception e )
Index: src/java/main/org/apache/maven/jelly/tags/maven/ContextVariableTag.java
===================================================================
RCS file: src/java/main/org/apache/maven/jelly/tags/maven/ContextVariableTag.java
diff -N src/java/main/org/apache/maven/jelly/tags/maven/ContextVariableTag.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/java/main/org/apache/maven/jelly/tags/maven/ContextVariableTag.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,74 @@
+package org.apache.maven.jelly.tags.maven;
+
+/* ====================================================================
+ *   Copyright 2001-2004 The Apache Software Foundation.
+ *
+ *   Licensed 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.commons.jelly.JellyTagException;
+import org.apache.commons.jelly.MissingAttributeException;
+import org.apache.commons.jelly.XMLOutput;
+import org.apache.maven.jelly.tags.BaseTagSupport;
+
+/**
+ * A Maven Jelly tag that provides a context variable to the ancestor MavenTag
+ * (and therefore ReactorTag as that extends MavenTag).
+ *
+ * @author <a href="mailto:kris@kris.me.uk">Kris Brown</a>
+ */
+public class ContextVariableTag
+    extends BaseTagSupport
+{
+    private String var;
+    
+    private Object value;
+
+    public void setVar( String var )
+    {
+        this.var = var;
+    }
+
+    public void setValue( Object value )
+    {
+        this.value = value;
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.commons.jelly.Tag#doTag(org.apache.commons.jelly.XMLOutput)
+     */
+    public void doTag( XMLOutput output )
+        throws MissingAttributeException, JellyTagException
+    {
+        checkAttribute( var, "var" );
+
+        checkAttribute( value, "value" );
+
+        MavenTag tag = getAncestorMavenTag();
+        tag.putContextVariable(var, value);
+    }
+    
+    /**
+     * @return the ancestor MavenTag
+     */
+    protected MavenTag getAncestorMavenTag() throws JellyTagException {
+        MavenTag tag = (MavenTag) findAncestorWithClass(
+                new Class[] {MavenTag.class, ReactorTag.class});
+        if ( tag == null ) {
+            throw new JellyTagException( "<maven:contextVariable> must be " +
+                    "inside <maven:maven> or <maven:reactor>" );
+        }
+        return tag;
+    }    
+}