apache · nadment · Mar 31, 2025
diff --git a/docs/hop-user-manual/modules/ROOT/nav.adoc b/docs/hop-user-manual/modules/ROOT/nav.adoc
@@ -327,6 +327,7 @@ under the License.
 *** xref:workflow/actions/getpop.adoc[Get mails (POP3/IMAP)]
 *** xref:workflow/actions/http.adoc[HTTP]
 *** xref:workflow/actions/eval.adoc[JavaScript]
+*** xref:workflow/actions/join.adoc[Join]
 *** xref:workflow/actions/mail.adoc[Mail]
 *** xref:workflow/actions/mailvalidator.adoc[Mail validator]
 *** xref:workflow/actions/movefiles.adoc[Move files]

diff --git a/docs/hop-user-manual/modules/ROOT/pages/workflow/actions/join.adoc b/docs/hop-user-manual/modules/ROOT/pages/workflow/actions/join.adoc
@@ -0,0 +1,29 @@
+////
+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.
+////
+:documentationPath: /workflow/actions/
+:language: en_US
+:description: The Join action waits for parallel branches.
+
+= Join
+
+== Description
+
+The `Join` action waits for all parallel branches at the same level to complete before running the next action(s).
+
+== Usage
+
+By default, actions in a workflow run sequentially. To organize actions into separate branches and run those branches at the same time, you can execute parallel branches, and then join those branches later in your workflow.
diff --git a/engine/src/main/java/org/apache/hop/core/gui/IGc.java b/engine/src/main/java/org/apache/hop/core/gui/IGc.java
@@ -86,6 +86,7 @@ enum EImage {
     PARALLEL,
     PARALLEL_DISABLED,
     BUSY,
+    WAITING,
     INJECT,
     LOAD_BALANCE,
     CHECKPOINT,

diff --git a/engine/src/main/java/org/apache/hop/core/gui/SvgGc.java b/engine/src/main/java/org/apache/hop/core/gui/SvgGc.java
@@ -77,6 +77,7 @@ public class SvgGc implements IGc {
   private static SvgFile imageUnconditional;
   private static SvgFile imageUnconditionalDisabled;
   private static SvgFile imageBusy;
+  private static SvgFile imageWaiting;
   private static SvgFile imageMissing;
   private static SvgFile imageDeprecated;
   private static SvgFile imageInject;
@@ -234,6 +235,7 @@ private void init() {
     imageUnconditionalDisabled =
         new SvgFile("ui/images/unconditional-disabled.svg", this.getClass().getClassLoader());
     imageBusy = new SvgFile("ui/images/busy.svg", this.getClass().getClassLoader());
+    imageWaiting = new SvgFile("ui/images/waiting.svg", this.getClass().getClassLoader());
     imageInject = new SvgFile("ui/images/inject.svg", this.getClass().getClassLoader());
     imageMissing = new SvgFile("ui/images/missing.svg", this.getClass().getClassLoader());
     imageDeprecated = new SvgFile("ui/images/deprecated.svg", this.getClass().getClassLoader());
@@ -594,80 +596,45 @@ public Point getArea() {
     return area;
   }
 
-  public static final SvgFile getNativeImage(EImage image) {
-    switch (image) {
-      case LOCK:
-        return imageLocked;
-      case FAILURE:
-        return imageFailure;
-      case EDIT:
-        return imageEdit;
-      case CONTEXT_MENU:
-        return imageContextMenu;
-      case TRUE:
-        return imageTrue;
-      case TRUE_DISABLED:
-        return imageTrueDisabled;
-      case FALSE:
-        return imageFalse;
-      case FALSE_DISABLED:
-        return imageFalseDisabled;
-      case ERROR:
-        return imageError;
-      case ERROR_DISABLED:
-        return imageErrorDisabled;
-      case INFO:
-        return imageInfo;
-      case INFO_DISABLED:
-        return imageInfoDisabled;
-      case TARGET:
-        return imageTarget;
-      case TARGET_DISABLED:
-        return imageTargetDisabled;
-      case INPUT:
-        return imageInput;
-      case OUTPUT:
-        return imageOutput;
-      case ARROW:
-        return imageArrow;
-      case COPY_ROWS:
-        return imageCopyRows;
-      case COPY_ROWS_DISABLED:
-        return imageCopyRowsDisabled;
-      case LOAD_BALANCE:
-        return imageLoadBalance;
-      case CHECKPOINT:
-        return imageCheckpoint;
-      case DB:
-        return imageDatabase;
-      case PARALLEL:
-        return imageParallel;
-      case PARALLEL_DISABLED:
-        return imageParallelDisabled;
-      case UNCONDITIONAL:
-        return imageUnconditional;
-      case UNCONDITIONAL_DISABLED:
-        return imageUnconditionalDisabled;
-      case BUSY:
-        return imageBusy;
-      case INJECT:
-        return imageInject;
-      case ARROW_DEFAULT:
-        return imageArrowDefault;
-      case ARROW_TRUE:
-        return imageArrowTrue;
-      case ARROW_FALSE:
-        return imageArrowFalse;
-      case ARROW_ERROR:
-        return imageArrowError;
-      case ARROW_DISABLED:
-        return imageArrowDisabled;
-      case DATA:
-        return imageData;
-      default:
-        break;
-    }
-    return null;
+  public SvgFile getNativeImage(EImage image) {
+    return switch (image) {
+      case LOCK -> imageLocked;
+      case FAILURE -> imageFailure;
+      case EDIT -> imageEdit;
+      case CONTEXT_MENU -> imageContextMenu;
+      case TRUE -> imageTrue;
+      case TRUE_DISABLED -> imageTrueDisabled;
+      case FALSE -> imageFalse;
+      case FALSE_DISABLED -> imageFalseDisabled;
+      case ERROR -> imageError;
+      case ERROR_DISABLED -> imageErrorDisabled;
+      case INFO -> imageInfo;
+      case INFO_DISABLED -> imageInfoDisabled;
+      case TARGET -> imageTarget;
+      case TARGET_DISABLED -> imageTargetDisabled;
+      case INPUT -> imageInput;
+      case OUTPUT -> imageOutput;
+      case ARROW -> imageArrow;
+      case COPY_ROWS -> imageCopyRows;
+      case COPY_ROWS_DISABLED -> imageCopyRowsDisabled;
+      case LOAD_BALANCE -> imageLoadBalance;
+      case CHECKPOINT -> imageCheckpoint;
+      case DB -> imageDatabase;
+      case PARALLEL -> imageParallel;
+      case PARALLEL_DISABLED -> imageParallelDisabled;
+      case UNCONDITIONAL -> imageUnconditional;
+      case UNCONDITIONAL_DISABLED -> imageUnconditionalDisabled;
+      case BUSY -> imageBusy;
+      case WAITING -> imageWaiting;
+      case INJECT -> imageInject;
+      case ARROW_DEFAULT -> imageArrowDefault;
+      case ARROW_TRUE -> imageArrowTrue;
+      case ARROW_FALSE -> imageArrowFalse;
+      case ARROW_ERROR -> imageArrowError;
+      case ARROW_DISABLED -> imageArrowDisabled;
+      case DATA -> imageData;
+      default -> null;
+    };
   }
 
   @Override

diff --git a/engine/src/main/java/org/apache/hop/workflow/Workflow.java b/engine/src/main/java/org/apache/hop/workflow/Workflow.java
@@ -714,7 +714,7 @@ private Result executeFromStart(
                 + ")");
       }
 
-      // Which entry is next?
+      // Which action is next?
       IAction action = actionMeta.getAction();
       action.getLogChannel().setLogLevel(logLevel);
 
@@ -821,11 +821,11 @@ private Result executeFromStart(
       final ActionMeta nextAction = workflowMeta.findNextAction(actionMeta, i);
 
       // See if we need to execute this...
-      final WorkflowHopMeta hi = workflowMeta.findWorkflowHop(actionMeta, nextAction);
+      final WorkflowHopMeta hopMeta = workflowMeta.findWorkflowHop(actionMeta, nextAction);
 
       // The next comment...
       final String nextComment;
-      if (hi.isUnconditional()) {
+      if (hopMeta.isUnconditional()) {
         nextComment = BaseMessages.getString(PKG, "Workflow.Comment.FollowedUnconditional");
       } else {
         if (newResult.getResult()) {
@@ -840,9 +840,17 @@ private Result executeFromStart(
       // If the start point was an evaluation and the link color is correct:
       // green or red, execute the next action...
       //
-      if (hi.isUnconditional()
-          || (actionMeta.isEvaluation() && (hi.isEvaluation() == newResult.getResult()))) {
-        // Start this next transform!
+      if (hopMeta.isUnconditional()
+          || (actionMeta.isEvaluation() && (hopMeta.isEvaluation() == newResult.getResult()))) {
+
+        // If the next action is a join, only execute once
+        if (nextAction.isJoin()) {
+          if (activeActions.contains(nextAction)) {
+            continue;
+          }
+        }
+
+        // Start this next action!
         if (log.isBasic()) {
           log.logBasic(
               BaseMessages.getString(PKG, "Workflow.Log.StartingAction", nextAction.getName()));
@@ -1490,9 +1498,9 @@ public void setInteractive(boolean interactive) {
   }
 
   /**
-   * Gets the activeJobEntryPipelines.
+   * Gets the active actions.
    *
-   * @return the activeJobEntryPipelines
+   * @return the active actions
    */
   @Override
   public Set<ActionMeta> getActiveActions() {

diff --git a/engine/src/main/java/org/apache/hop/workflow/WorkflowPainter.java b/engine/src/main/java/org/apache/hop/workflow/WorkflowPainter.java
@@ -318,7 +318,8 @@ protected void drawAction(ActionMeta actionMeta) throws HopException {
       gc.setForeground(EColor.BLUE);
       int iconX = (x + iconSize) - (miniIconSize / 2) + 1;
       int iconY = y - (miniIconSize / 2) - 1;
-      gc.drawImage(EImage.BUSY, iconX, iconY, magnification);
+
+      gc.drawImage(actionMeta.isJoin() ? EImage.WAITING : EImage.BUSY, iconX, iconY, magnification);
       areaOwners.add(
           new AreaOwner(
               AreaType.ACTION_BUSY,

diff --git a/engine/src/main/java/org/apache/hop/workflow/action/ActionBase.java b/engine/src/main/java/org/apache/hop/workflow/action/ActionBase.java
@@ -294,6 +294,11 @@ public boolean isStart() {
     return false;
   }
 
+  @Override
+  public boolean isJoin() {
+    return false;
+  }
+
   /**
    * Checks if the action executes a workflow
    *

diff --git a/engine/src/main/java/org/apache/hop/workflow/action/ActionMeta.java b/engine/src/main/java/org/apache/hop/workflow/action/ActionMeta.java
@@ -39,7 +39,7 @@
 
 /**
  * This class describes the fact that a single Action can be used multiple times in the same
- * Workflow. Therefore it contains a link to a Action, a position, a number, etc.
+ * Workflow. Therefore, it contains a link to an Action, a position, a number, etc.
  */
 public class ActionMeta implements Cloneable, IGuiPosition, IChanged, IAttributes, IBaseMeta {
   public static final String XML_TAG = "action";
@@ -302,6 +302,10 @@ public boolean isStart() {
     return action.isStart();
   }
 
+  public boolean isJoin() {
+    return action.isJoin();
+  }
+
   public boolean isMissing() {
     return action instanceof MissingAction;
   }

diff --git a/engine/src/main/java/org/apache/hop/workflow/action/IAction.java b/engine/src/main/java/org/apache/hop/workflow/action/IAction.java
@@ -265,6 +265,13 @@ void loadXml(Node actionNode, IHopMetadataProvider metadataProvider, IVariables
    */
   boolean isStart();
 
+  /**
+   * Checks if the action is a join point of parallel execution
+   *
+   * @return true if joining point, false otherwise
+   */
+  boolean isJoin();
+
   /**
    * This method is called when a action is duplicated in HopGui. It needs to return a deep copy of
    * this action object. It is essential that the implementing class creates proper deep copies if

diff --git a/plugins/actions/join/pom.xml b/plugins/actions/join/pom.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ 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.
+  ~
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.apache.hop</groupId>
+        <artifactId>hop-plugins-actions</artifactId>
+        <version>2.13.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>hop-action-join</artifactId>
+    <packaging>jar</packaging>
+    <name>Hop Plugins Actions Join</name>
+
+</project>
diff --git a/plugins/actions/join/src/assembly/assembly.xml b/plugins/actions/join/src/assembly/assembly.xml
@@ -0,0 +1,50 @@
+<!--
+  ~ 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.
+  ~
+  -->
+
+<assembly xmlns="http://maven.apache.org/ASSEMBLY/2.2.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/ASSEMBLY/2.2.0 http://maven.apache.org/xsd/assembly-2.2.0.xsd">
+    <id>hop-action-join</id>
+    <formats>
+        <format>zip</format>
+    </formats>
+    <baseDirectory>.</baseDirectory>
+    <files>
+        <file>
+            <source>${project.basedir}/src/main/resources/version.xml</source>
+            <outputDirectory>plugins/actions/join</outputDirectory>
+            <filtered>true</filtered>
+        </file>
+    </files>
+
+    <fileSets>
+        <fileSet>
+            <directory>${project.basedir}/src/main/samples</directory>
+            <outputDirectory>config/projects/samples/</outputDirectory>
+        </fileSet>
+    </fileSets>
+
+    <dependencySets>
+        <dependencySet>
+            <includes>
+                <include>org.apache.hop:hop-action-join:jar</include>
+            </includes>
+            <outputDirectory>plugins/actions/join</outputDirectory>
+        </dependencySet>
+    </dependencySets>
+</assembly>