Add onWorkflowPublish event to TraceObserverV2

modules/nextflow/src/main/groovy/nextflow/Session.groovy

@@ -79,6 +79,7 @@ import nextflow.trace.WorkflowStatsObserver
 import nextflow.trace.event.FilePublishEvent
 import nextflow.trace.event.TaskEvent
 import nextflow.trace.event.WorkflowOutputEvent
+import nextflow.trace.event.WorkflowPublishEvent
 import nextflow.util.Barrier
 import nextflow.util.ConfigHelper
 import nextflow.util.Duration
@@ -1067,15 +1068,19 @@ class Session implements ISession {
         notifyEvent(observersV2, ob -> ob.onFlowCreate(this))
     }
 
-    void notifyWorkflowOutput(WorkflowOutputEvent event) {
-        notifyEvent(observersV2, ob -> ob.onWorkflowOutput(event))
-    }
-
     void notifyFilePublish(FilePublishEvent event) {
         notifyEvent(observersV1, ob -> ob.onFilePublish(event.target, event.source))
         notifyEvent(observersV2, ob -> ob.onFilePublish(event))
     }
 
+    void notifyWorkflowPublish(WorkflowPublishEvent event) {
+        notifyEvent(observersV2, ob -> ob.onWorkflowPublish(event))
+    }
+
+    void notifyWorkflowOutput(WorkflowOutputEvent event) {
+        notifyEvent(observersV2, ob -> ob.onWorkflowOutput(event))
+    }
+
     void notifyFlowComplete() {
         notifyEvent(observersV1, ob -> ob.onFlowComplete())
         notifyEvent(observersV2, ob -> ob.onFlowComplete())

modules/nextflow/src/main/groovy/nextflow/extension/PublishOp.groovy

@@ -26,6 +26,7 @@ import nextflow.exception.ScriptRuntimeException
 import nextflow.processor.PublishDir
 import nextflow.trace.event.FilePublishEvent
 import nextflow.trace.event.WorkflowOutputEvent
+import nextflow.trace.event.WorkflowPublishEvent
 import nextflow.util.CsvWriter
 /**
  * Publish a workflow output.
@@ -51,7 +52,7 @@ class PublishOp {
 
     private IndexOpts indexOpts
 
-    private List indexRecords = []
+    private List publishedValues = []
 
     private volatile boolean complete
 
@@ -86,7 +87,7 @@ class PublishOp {
      * @param value
      */
     protected void onNext(value) {
-        log.trace "Publish operator received: $value"
+        log.trace "Received value for workflow output '${name}': ${value}"
 
         // evaluate dynamic path
         final targetResolver = getTargetDir(value)
@@ -110,10 +111,12 @@ class PublishOp {
             publisher.apply(files, sourceDir)
         }
 
-        // append record to index
-        final normalized = normalizePaths(value, targetResolver)
-        log.trace "Normalized record for index file: ${normalized}"
-        indexRecords << normalized
+        // publish value to workflow output
+        final normalizedValue = normalizeValue(value, targetResolver)
+
+        log.trace "Published value to workflow output '${name}': ${normalizedValue}"
+        publishedValues << normalizedValue
+        session.notifyWorkflowPublish(new WorkflowPublishEvent(name, normalizedValue))
     }
 
     /**
@@ -195,34 +198,34 @@ class PublishOp {
      */
     protected void onComplete(nope) {
         // publish individual record if source is a value channel
-        final value = CH.isValue(source)
-            ? indexRecords.first()
-            : indexRecords
+        final outputValue = CH.isValue(source)
+            ? publishedValues.first()
+            : publishedValues
 
         // publish workflow output
         final indexPath = indexOpts ? indexOpts.path : null
-        session.notifyWorkflowOutput(new WorkflowOutputEvent(name, value, indexPath))
+        session.notifyWorkflowOutput(new WorkflowOutputEvent(name, outputValue, indexPath))
 
         // write value to index file
         if( indexOpts ) {
             final ext = indexPath.getExtension()
             indexPath.parent.mkdirs()
             if( ext == 'csv' ) {
-                new CsvWriter(header: indexOpts.header, sep: indexOpts.sep).apply(indexRecords, indexPath)
+                new CsvWriter(header: indexOpts.header, sep: indexOpts.sep).apply(publishedValues, indexPath)
             }
             else if( ext == 'json' ) {
-                indexPath.text = DumpHelper.prettyPrintJson(value)
+                indexPath.text = DumpHelper.prettyPrintJson(outputValue)
             }
             else if( ext == 'yaml' || ext == 'yml' ) {
-                indexPath.text = DumpHelper.prettyPrintYaml(value)
+                indexPath.text = DumpHelper.prettyPrintYaml(outputValue)
             }
             else {
                 log.warn "Invalid extension '${ext}' for index file '${indexPath}' -- should be CSV, JSON, or YAML"
             }
             session.notifyFilePublish(new FilePublishEvent(null, indexPath, publishOpts.labels as List))
         }
 
-        log.trace "Publish operator complete"
+        log.trace "Completed workflow output '${name}'"
         this.complete = true
     }
 
@@ -260,7 +263,7 @@ class PublishOp {
      * @param value
      * @param targetResolver
      */
-    protected Object normalizePaths(value, targetResolver) {
+    protected Object normalizeValue(value, targetResolver) {
         if( value instanceof Path ) {
             return normalizePath(value, targetResolver)
         }
@@ -270,9 +273,9 @@ class PublishOp {
                 if( el instanceof Path )
                     return normalizePath(el, targetResolver)
                 if( el instanceof Collection<Path> )
-                    return normalizePaths(el, targetResolver)
+                    return normalizeValue(el, targetResolver)
                 if( el instanceof Map )
-                    return normalizePaths(el, targetResolver)
+                    return normalizeValue(el, targetResolver)
                 return el
             }
         }
@@ -282,9 +285,9 @@ class PublishOp {
                 if( v instanceof Path )
                     return [k, normalizePath(v, targetResolver)]
                 if( v instanceof Collection<Path> )
-                    return [k, normalizePaths(v, targetResolver)]
+                    return [k, normalizeValue(v, targetResolver)]
                 if( v instanceof Map )
-                    return [k, normalizePaths(v, targetResolver)]
+                    return [k, normalizeValue(v, targetResolver)]
                 return [k, v]
             }
         }

modules/nextflow/src/main/groovy/nextflow/trace/TraceObserverV2.groovy

@@ -23,6 +23,7 @@ import nextflow.processor.TaskProcessor
 import nextflow.trace.event.FilePublishEvent
 import nextflow.trace.event.TaskEvent
 import nextflow.trace.event.WorkflowOutputEvent
+import nextflow.trace.event.WorkflowPublishEvent
 
 /**
  * Interface for consuming workflow lifecycle events.
@@ -121,18 +122,34 @@ interface TraceObserverV2 {
     default void onFlowError(TaskEvent event) {}
 
     /**
-     * Invoked when a workflow output is published.
+     * Invoked when a file is published by a workflow output
+     * or `publishDir` directive.
      *
      * @param event
      */
-    default void onWorkflowOutput(WorkflowOutputEvent event) {}
+    default void onFilePublish(FilePublishEvent event) {}
 
     /**
-     * Invoked when a file is published, either by a `publishDir` directive
-     * or a workflow output.
+     * Invoked when a workflow output receives a value from
+     * a dataflow source.
+     *
+     * For a given published value, this event is guaranteed
+     * to be emitted after all files in that value have been
+     * published via onFilePublish().
      *
      * @param event
      */
-    default void onFilePublish(FilePublishEvent event) {}
+    default void onWorkflowPublish(WorkflowPublishEvent event) {}
+
+    /**
+     * Invoked when a workflow output is completed.
+     *
+     * For a given workflow output, this event is guaranteed
+     * to be emitted after all values for that output have been
+     * published via onWorkflowPublish().
+     *
+     * @param event
+     */
+    default void onWorkflowOutput(WorkflowOutputEvent event) {}
 
 }

modules/nextflow/src/main/groovy/nextflow/trace/event/FilePublishEvent.groovy

@@ -22,7 +22,8 @@ import groovy.transform.Canonical
 import groovy.transform.CompileStatic
 
 /**
- * Models a file publish event.
+ * Models a file publish event, which is emitted for each file
+ * that is published in a workflow output or publishDir.
  *
  * @author Ben Sherman <[email protected]>
  */

modules/nextflow/src/main/groovy/nextflow/trace/event/WorkflowOutputEvent.groovy

@@ -22,7 +22,8 @@ import groovy.transform.Canonical
 import groovy.transform.CompileStatic
 
 /**
- * Models a workflow output event.
+ * Models a workflow output event, which is emitted for each
+ * workflow output when it is completed.
  *
  * @author Ben Sherman <[email protected]>
  */
@@ -34,7 +35,13 @@ class WorkflowOutputEvent {
      */
     String name
     /**
-     * The value of the workflow output. It will be null if the index file was specified.
+     * The value of the workflow output.
+     *
+     * If the source is a dataflow channel. this value is an unordered
+     * collection of the published values from the channel. If the source
+     * is a dataflow value, this value is the published value.
+     *
+     * If the index file was enabled, this value is null.
      */
     Object value
     /**

modules/nextflow/src/main/groovy/nextflow/trace/event/WorkflowPublishEvent.groovy

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2013-2024, Seqera Labs
+ *
+ * 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.
+ */
+
+package nextflow.trace.event
+
+import groovy.transform.Canonical
+import groovy.transform.CompileStatic
+
+/**
+ * Models a workflow publish event, which is emitted for each value
+ * that is published to a workflow output from a dataflow source.
+ *
+ * @author Rob Syme <[email protected]>
+ */
+@Canonical
+@CompileStatic
+class WorkflowPublishEvent {
+    /**
+     * The name of the workflow output.
+     */
+    String name
+    /**
+     * The published value.
+     *
+     * File paths from the work directory are normalized to
+     * their corresponding path in the output directory.
+     */
+    Object value
+}

modules/nextflow/src/test/groovy/nextflow/script/OutputDslTest.groovy

@@ -10,6 +10,7 @@ import nextflow.Session
 import nextflow.SysEnv
 import nextflow.trace.event.FilePublishEvent
 import nextflow.trace.event.WorkflowOutputEvent
+import nextflow.trace.event.WorkflowPublishEvent
 import spock.lang.Specification
 /**
  *
@@ -88,6 +89,8 @@ class OutputDslTest extends Specification {
         and:
         1 * session.notifyFilePublish(new FilePublishEvent(file1, outputDir.resolve('foo/file1.txt'), null))
         1 * session.notifyFilePublish(new FilePublishEvent(file2, outputDir.resolve('barbar/file2.txt'), ['foo', 'bar']))
+        1 * session.notifyWorkflowPublish(new WorkflowPublishEvent('foo', outputDir.resolve('foo/file1.txt')))
+        1 * session.notifyWorkflowPublish(new WorkflowPublishEvent('bar', outputDir.resolve('barbar/file2.txt')))
         1 * session.notifyWorkflowOutput(new WorkflowOutputEvent('foo', [outputDir.resolve('foo/file1.txt')], null))
         1 * session.notifyWorkflowOutput(new WorkflowOutputEvent('bar', [outputDir.resolve('barbar/file2.txt')], outputDir.resolve('index.csv')))
         1 * session.notifyFilePublish(new FilePublishEvent(null, outputDir.resolve('index.csv'), ['foo', 'bar']))
@@ -128,6 +131,7 @@ class OutputDslTest extends Specification {
         outputDir.resolve('file1.txt').text == 'Hello'
         and:
         1 * session.notifyFilePublish(new FilePublishEvent(file1, outputDir.resolve('file1.txt'), null))
+        1 * session.notifyWorkflowPublish(new WorkflowPublishEvent('foo', outputDir.resolve('file1.txt')))
         1 * session.notifyWorkflowOutput(new WorkflowOutputEvent('foo', [outputDir.resolve('file1.txt')], null))
 
         cleanup:
@@ -166,6 +170,7 @@ class OutputDslTest extends Specification {
         await(dsl)
         then:
         0 * session.notifyFilePublish(_)
+        1 * session.notifyWorkflowPublish(new WorkflowPublishEvent('foo', record))
         1 * session.notifyWorkflowOutput(new WorkflowOutputEvent('foo', [ record ], null))
 
         cleanup: