Remove implicit conversion because of side effect

spark/src/main/java/org/apache/zeppelin/spark/SparkInterpreter.java

@@ -464,16 +464,6 @@ public class SparkInterpreter extends Interpreter {
         }
       }
     }
-
-    // add some implicit conversion
-    intp.interpret("implicit def watcherConversion(watcher: (Object, Object) => Unit):"
-        + "org.apache.zeppelin.display.AngularObjectWatcher = {"
-        + "  new org.apache.zeppelin.display.AngularObjectWatcher() {"
-        + "    def watch(before:Object, after:Object) = {"
-        + "      watcher(before, after)"
-        + "    }"
-        + "  }"
-        + "}");
   }
 
   private List<File> currentClassPath() {

spark/src/main/java/org/apache/zeppelin/spark/ZeppelinContext.java

@@ -46,6 +46,7 @@ import org.apache.zeppelin.interpreter.InterpreterException;
 import org.apache.zeppelin.spark.dep.DependencyResolver;
 
 import scala.Tuple2;
+import scala.Unit;
 import scala.collection.Iterable;
 
 /**
@@ -502,6 +503,32 @@ public class ZeppelinContext extends HashMap<String, Object> {
     }
   }
 
+
+  public void angularWatch(String name,
+      final scala.Function2<Object, Object, Unit> func) {
+    AngularObjectWatcher w = new AngularObjectWatcher(getInterpreterContext()) {
+      @Override
+      public void watch(Object oldObject, Object newObject,
+          InterpreterContext context) {
+        func.apply(newObject, newObject);
+      }
+    };
+    angularWatch(name, w);
+  }
+
+  public void angularWatch(
+      String name,
+      final scala.Function3<Object, Object, InterpreterContext, Unit> func) {
+    AngularObjectWatcher w = new AngularObjectWatcher(getInterpreterContext()) {
+      @Override
+      public void watch(Object oldObject, Object newObject,
+          InterpreterContext context) {
+        func.apply(oldObject, newObject, context);
+      }
+    };
+    angularWatch(name, w);
+  }
+
   public void angularUnwatch(String name, AngularObjectWatcher w) {
     AngularObjectRegistry registry = interpreterContext.getAngularObjectRegistry();
     if (registry.get(name) != null) {

zeppelin-interpreter/src/main/java/org/apache/zeppelin/display/AngularObjectWatcher.java

@@ -17,9 +17,21 @@
 
 package org.apache.zeppelin.display;
 
+import org.apache.zeppelin.interpreter.InterpreterContext;
+
 /**
  *
  */
-public interface AngularObjectWatcher {
-  public void watch(Object oldObject, Object newObject);
+public abstract class AngularObjectWatcher {
+  private InterpreterContext context;
+
+  public AngularObjectWatcher(InterpreterContext context) {
+    this.context = context;
+  }
+
+  void watch(Object oldObject, Object newObject) {
+    watch(oldObject, newObject, context);
+  }
+
+  public abstract void watch(Object oldObject, Object newObject, InterpreterContext context);
 }

zeppelin-interpreter/src/test/java/org/apache/zeppelin/display/AngularObjectTest.java

@@ -21,6 +21,7 @@ import static org.junit.Assert.assertEquals;
 
 import java.util.concurrent.atomic.AtomicInteger;
 
+import org.apache.zeppelin.interpreter.InterpreterContext;
 import org.junit.Test;
 
 public class AngularObjectTest {
@@ -61,9 +62,9 @@ public class AngularObjectTest {
       }
     });
 
-    ao.addWatcher(new AngularObjectWatcher() {
+    ao.addWatcher(new AngularObjectWatcher(null) {
       @Override
-      public void watch(Object oldObject, Object newObject) {
+      public void watch(Object oldObject, Object newObject, InterpreterContext context) {
         onWatch.incrementAndGet();
       }
     });

zeppelin-interpreter/src/test/java/org/apache/zeppelin/interpreter/remote/mock/MockInterpreterAngular.java

@@ -29,7 +29,7 @@ import org.apache.zeppelin.interpreter.InterpreterPropertyBuilder;
 import org.apache.zeppelin.interpreter.InterpreterResult;
 import org.apache.zeppelin.interpreter.InterpreterResult.Code;
 
-public class MockInterpreterAngular extends Interpreter implements AngularObjectWatcher {
+public class MockInterpreterAngular extends Interpreter {
   static {
     Interpreter.register(
         "angularTest",
@@ -72,7 +72,15 @@ public class MockInterpreterAngular extends Interpreter implements AngularObject
 
     if (cmd.equals("add")) {
       registry.add(name, value);
-      registry.get(name).addWatcher(this);
+      registry.get(name).addWatcher(new AngularObjectWatcher(null) {
+
+        @Override
+        public void watch(Object oldObject, Object newObject,
+            InterpreterContext context) {
+          numWatch.incrementAndGet();
+        }
+
+      });
     } else if (cmd.equalsIgnoreCase("update")) {
       registry.get(name).set(value);
     } else if (cmd.equals("remove")) {
@@ -106,10 +114,4 @@ public class MockInterpreterAngular extends Interpreter implements AngularObject
   public List<String> completion(String buf, int cursor) {
     return null;
   }
-
-  @Override
-  public void watch(Object oldObject, Object newObject) {
-    numWatch.incrementAndGet();
-  }
-
 }