Make log of each separate child algorithm available for retrieval after

running model

python/PyQt6/core/auto_generated/processing/qgsprocessingcontext.sip.in

@@ -67,6 +67,20 @@ Returns the outputs generated by the child algorithm.
 Sets the ``outputs`` used for the child algorithm.
 
 .. seealso:: :py:func:`outputs`
+%End
+
+    QString htmlLog() const;
+%Docstring
+Returns the HTML formatted contents of logged messages which occurred while running the child.
+
+.. seealso:: :py:func:`setHtmlLog`
+%End
+
+    void setHtmlLog( const QString &log );
+%Docstring
+Sets the HTML formatted contents of logged messages which occurred while running the child.
+
+.. seealso:: :py:func:`htmlLog`
 %End
 
     bool operator==( const QgsProcessingModelChildAlgorithmResult &other ) const;

python/core/auto_generated/processing/qgsprocessingcontext.sip.in

@@ -67,6 +67,20 @@ Returns the outputs generated by the child algorithm.
 Sets the ``outputs`` used for the child algorithm.
 
 .. seealso:: :py:func:`outputs`
+%End
+
+    QString htmlLog() const;
+%Docstring
+Returns the HTML formatted contents of logged messages which occurred while running the child.
+
+.. seealso:: :py:func:`setHtmlLog`
+%End
+
+    void setHtmlLog( const QString &log );
+%Docstring
+Sets the HTML formatted contents of logged messages which occurred while running the child.
+
+.. seealso:: :py:func:`htmlLog`
 %End
 
     bool operator==( const QgsProcessingModelChildAlgorithmResult &other ) const;

src/core/processing/models/qgsprocessingmodelalgorithm.cpp

@@ -326,6 +326,7 @@ QVariantMap QgsProcessingModelAlgorithm::processAlgorithm( const QVariantMap &pa
   QVariantMap finalResults;
   QSet< QString > executed;
   bool executedAlg = true;
+  int previousHtmlLogLength = 0;
   while ( executedAlg && executed.count() < toExecute.count() )
   {
     executedAlg = false;
@@ -503,124 +504,142 @@ QVariantMap QgsProcessingModelAlgorithm::processAlgorithm( const QVariantMap &pa
       childResults.insert( childId, results );
       childResult.setOutputs( results );
 
-      context.modelChildResults().insert( childId, childResult );
+      if ( runResult )
+      {
+        if ( feedback && !skipGenericLogging )
+        {
+          const QVariantMap displayOutputs = QgsProcessingUtils::removePointerValuesFromMap( results );
+          QStringList formattedOutputs;
+          for ( auto displayOutputIt = displayOutputs.constBegin(); displayOutputIt != displayOutputs.constEnd(); ++displayOutputIt )
+          {
+            formattedOutputs << QStringLiteral( "%1: %2" ).arg( displayOutputIt.key(),
+                             QgsProcessingUtils::variantToPythonLiteral( displayOutputIt.value() ) );;
+          }
+          feedback->pushInfo( QObject::tr( "Results:" ) );
+          feedback->pushCommandInfo( QStringLiteral( "{ %1 }" ).arg( formattedOutputs.join( QLatin1String( ", " ) ) ) );
+        }
+
+        // look through child alg's outputs to determine whether any of these should be copied
+        // to the final model outputs
+        const QMap<QString, QgsProcessingModelOutput> outputs = child.modelOutputs();
+        for ( auto outputIt = outputs.constBegin(); outputIt != outputs.constEnd(); ++outputIt )
+        {
+          const int outputSortKey = mOutputOrder.indexOf( QStringLiteral( "%1:%2" ).arg( childId, outputIt->childOutputName() ) );
+          switch ( mInternalVersion )
+          {
+            case QgsProcessingModelAlgorithm::InternalVersion::Version1:
+              finalResults.insert( childId + ':' + outputIt->name(), results.value( outputIt->childOutputName() ) );
+              break;
+            case QgsProcessingModelAlgorithm::InternalVersion::Version2:
+              if ( const QgsProcessingParameterDefinition *modelParam = modelParameterFromChildIdAndOutputName( child.childId(), outputIt.key() ) )
+              {
+                finalResults.insert( modelParam->name(), results.value( outputIt->childOutputName() ) );
+              }
+              break;
+          }
+
+          if ( !results.value( outputIt->childOutputName() ).toString().isEmpty() )
+          {
+            QgsProcessingContext::LayerDetails &details = context.layerToLoadOnCompletionDetails( results.value( outputIt->childOutputName() ).toString() );
+            details.groupName = mOutputGroup;
+            if ( outputSortKey > 0 )
+              details.layerSortKey = outputSortKey;
+          }
+        }
+
+        executed.insert( childId );
+
+        std::function< void( const QString &, const QString & )> pruneAlgorithmBranchRecursive;
+        pruneAlgorithmBranchRecursive = [&]( const QString & id, const QString &branch = QString() )
+        {
+          const QSet<QString> toPrune = dependentChildAlgorithms( id, branch );
+          for ( const QString &targetId : toPrune )
+          {
+            if ( executed.contains( targetId ) )
+              continue;
+
+            executed.insert( targetId );
+            pruneAlgorithmBranchRecursive( targetId, branch );
+          }
+        };
+
+        // prune remaining algorithms if they are dependent on a branch from this child which didn't eventuate
+        const QgsProcessingOutputDefinitions outputDefs = childAlg->outputDefinitions();
+        for ( const QgsProcessingOutputDefinition *outputDef : outputDefs )
+        {
+          if ( outputDef->type() == QgsProcessingOutputConditionalBranch::typeName() && !results.value( outputDef->name() ).toBool() )
+          {
+            pruneAlgorithmBranchRecursive( childId, outputDef->name() );
+          }
+        }
+
+        if ( childAlg->flags() & Qgis::ProcessingAlgorithmFlag::PruneModelBranchesBasedOnAlgorithmResults )
+        {
+          // check if any dependent algorithms should be canceled based on the outputs of this algorithm run
+          // first find all direct dependencies of this algorithm by looking through all remaining child algorithms
+          for ( const QString &candidateId : std::as_const( toExecute ) )
+          {
+            if ( executed.contains( candidateId ) )
+              continue;
+
+            // a pending algorithm was found..., check it's parameter sources to see if it links to any of the current
+            // algorithm's outputs
+            const QgsProcessingModelChildAlgorithm &candidate = mChildAlgorithms[ candidateId ];
+            const QMap<QString, QgsProcessingModelChildParameterSources> candidateParams = candidate.parameterSources();
+            QMap<QString, QgsProcessingModelChildParameterSources>::const_iterator paramIt = candidateParams.constBegin();
+            bool pruned = false;
+            for ( ; paramIt != candidateParams.constEnd(); ++paramIt )
+            {
+              for ( const QgsProcessingModelChildParameterSource &source : paramIt.value() )
+              {
+                if ( source.source() == Qgis::ProcessingModelChildParameterSource::ChildOutput && source.outputChildId() == childId )
+                {
+                  // ok, this one is dependent on the current alg. Did we get a value for it?
+                  if ( !results.contains( source.outputName() ) )
+                  {
+                    // oh no, nothing returned for this parameter. Gotta trim the branch back!
+                    pruned = true;
+                    // skip the dependent alg..
+                    executed.insert( candidateId );
+                    //... and everything which depends on it
+                    pruneAlgorithmBranchRecursive( candidateId, QString() );
+                    break;
+                  }
+                }
+              }
+              if ( pruned )
+                break;
+            }
+          }
+        }
+
+        childAlg.reset( nullptr );
+        modelFeedback.setCurrentStep( executed.count() );
+        if ( feedback && !skipGenericLogging )
+        {
+          feedback->pushInfo( QObject::tr( "OK. Execution took %1 s (%n output(s)).", nullptr, results.count() ).arg( childTime.elapsed() / 1000.0 ) );
+        }
+      }
+
+      // trim out just the portion of the overall log which relates to this child
+      const QString thisAlgorithmHtmlLog = feedback->htmlLog().mid( previousHtmlLogLength );
+      previousHtmlLogLength = feedback->htmlLog().length();
 
       if ( !runResult )
       {
+        const QString formattedException = QStringLiteral( "<span style=\"color:red\">%1</span><br/>" ).arg( error.toHtmlEscaped() ).replace( '\n', QLatin1String( "<br>" ) );
+        const QString formattedRunTime = QStringLiteral( "<span style=\"color:red\">%1</span><br/>" ).arg( QObject::tr( "Failed after %1 s." ).arg( childTime.elapsed() / 1000.0 ).toHtmlEscaped() ).replace( '\n', QLatin1String( "<br>" ) );
+
+        childResult.setHtmlLog( thisAlgorithmHtmlLog + formattedException + formattedRunTime );
+        context.modelChildResults().insert( childId, childResult );
+
         throw QgsProcessingException( error );
       }
-
+      else
-      if ( feedback && !skipGenericLogging )
       {
-        const QVariantMap displayOutputs = QgsProcessingUtils::removePointerValuesFromMap( results );
+        childResult.setHtmlLog( thisAlgorithmHtmlLog );
-        QStringList formattedOutputs;
+        context.modelChildResults().insert( childId, childResult );
-        for ( auto displayOutputIt = displayOutputs.constBegin(); displayOutputIt != displayOutputs.constEnd(); ++displayOutputIt )
-        {
-          formattedOutputs << QStringLiteral( "%1: %2" ).arg( displayOutputIt.key(),
-                           QgsProcessingUtils::variantToPythonLiteral( displayOutputIt.value() ) );;
-        }
-        feedback->pushInfo( QObject::tr( "Results:" ) );
-        feedback->pushCommandInfo( QStringLiteral( "{ %1 }" ).arg( formattedOutputs.join( QLatin1String( ", " ) ) ) );
       }
-
-      // look through child alg's outputs to determine whether any of these should be copied
-      // to the final model outputs
-      const QMap<QString, QgsProcessingModelOutput> outputs = child.modelOutputs();
-      for ( auto outputIt = outputs.constBegin(); outputIt != outputs.constEnd(); ++outputIt )
-      {
-        const int outputSortKey = mOutputOrder.indexOf( QStringLiteral( "%1:%2" ).arg( childId, outputIt->childOutputName() ) );
-        switch ( mInternalVersion )
-        {
-          case QgsProcessingModelAlgorithm::InternalVersion::Version1:
-            finalResults.insert( childId + ':' + outputIt->name(), results.value( outputIt->childOutputName() ) );
-            break;
-          case QgsProcessingModelAlgorithm::InternalVersion::Version2:
-            if ( const QgsProcessingParameterDefinition *modelParam = modelParameterFromChildIdAndOutputName( child.childId(), outputIt.key() ) )
-            {
-              finalResults.insert( modelParam->name(), results.value( outputIt->childOutputName() ) );
-            }
-            break;
-        }
-
-        if ( !results.value( outputIt->childOutputName() ).toString().isEmpty() )
-        {
-          QgsProcessingContext::LayerDetails &details = context.layerToLoadOnCompletionDetails( results.value( outputIt->childOutputName() ).toString() );
-          details.groupName = mOutputGroup;
-          if ( outputSortKey > 0 )
-            details.layerSortKey = outputSortKey;
-        }
-      }
-
-      executed.insert( childId );
-
-      std::function< void( const QString &, const QString & )> pruneAlgorithmBranchRecursive;
-      pruneAlgorithmBranchRecursive = [&]( const QString & id, const QString &branch = QString() )
-      {
-        const QSet<QString> toPrune = dependentChildAlgorithms( id, branch );
-        for ( const QString &targetId : toPrune )
-        {
-          if ( executed.contains( targetId ) )
-            continue;
-
-          executed.insert( targetId );
-          pruneAlgorithmBranchRecursive( targetId, branch );
-        }
-      };
-
-      // prune remaining algorithms if they are dependent on a branch from this child which didn't eventuate
-      const QgsProcessingOutputDefinitions outputDefs = childAlg->outputDefinitions();
-      for ( const QgsProcessingOutputDefinition *outputDef : outputDefs )
-      {
-        if ( outputDef->type() == QgsProcessingOutputConditionalBranch::typeName() && !results.value( outputDef->name() ).toBool() )
-        {
-          pruneAlgorithmBranchRecursive( childId, outputDef->name() );
-        }
-      }
-
-      if ( childAlg->flags() & Qgis::ProcessingAlgorithmFlag::PruneModelBranchesBasedOnAlgorithmResults )
-      {
-        // check if any dependent algorithms should be canceled based on the outputs of this algorithm run
-        // first find all direct dependencies of this algorithm by looking through all remaining child algorithms
-        for ( const QString &candidateId : std::as_const( toExecute ) )
-        {
-          if ( executed.contains( candidateId ) )
-            continue;
-
-          // a pending algorithm was found..., check it's parameter sources to see if it links to any of the current
-          // algorithm's outputs
-          const QgsProcessingModelChildAlgorithm &candidate = mChildAlgorithms[ candidateId ];
-          const QMap<QString, QgsProcessingModelChildParameterSources> candidateParams = candidate.parameterSources();
-          QMap<QString, QgsProcessingModelChildParameterSources>::const_iterator paramIt = candidateParams.constBegin();
-          bool pruned = false;
-          for ( ; paramIt != candidateParams.constEnd(); ++paramIt )
-          {
-            for ( const QgsProcessingModelChildParameterSource &source : paramIt.value() )
-            {
-              if ( source.source() == Qgis::ProcessingModelChildParameterSource::ChildOutput && source.outputChildId() == childId )
-              {
-                // ok, this one is dependent on the current alg. Did we get a value for it?
-                if ( !results.contains( source.outputName() ) )
-                {
-                  // oh no, nothing returned for this parameter. Gotta trim the branch back!
-                  pruned = true;
-                  // skip the dependent alg..
-                  executed.insert( candidateId );
-                  //... and everything which depends on it
-                  pruneAlgorithmBranchRecursive( candidateId, QString() );
-                  break;
-                }
-              }
-            }
-            if ( pruned )
-              break;
-          }
-        }
-      }
-
-      childAlg.reset( nullptr );
-      modelFeedback.setCurrentStep( executed.count() );
-      if ( feedback && !skipGenericLogging )
-        feedback->pushInfo( QObject::tr( "OK. Execution took %1 s (%n output(s)).", nullptr, results.count() ).arg( childTime.elapsed() / 1000.0 ) );
     }
 
     if ( feedback && feedback->isCanceled() )

src/core/processing/qgsprocessingcontext.h

@@ -86,9 +86,24 @@ class CORE_EXPORT QgsProcessingModelChildAlgorithmResult
      */
     void setOutputs( const QVariantMap &outputs ) { mOutputs = outputs; }
 
+    /**
+     * Returns the HTML formatted contents of logged messages which occurred while running the child.
+     *
+     * \see setHtmlLog()
+     */
+    QString htmlLog() const { return mHtmlLog; }
+
+    /**
+     * Sets the HTML formatted contents of logged messages which occurred while running the child.
+     *
+     * \see htmlLog()
+     */
+    void setHtmlLog( const QString &log ) { mHtmlLog = log; }
+
     bool operator==( const QgsProcessingModelChildAlgorithmResult &other ) const
     {
       return mExecutionStatus == other.mExecutionStatus
+             && mHtmlLog == other.mHtmlLog
              && mInputs == other.mInputs
              && mOutputs == other.mOutputs;
     }
@@ -102,6 +117,7 @@ class CORE_EXPORT QgsProcessingModelChildAlgorithmResult
     Qgis::ProcessingModelChildAlgorithmExecutionStatus mExecutionStatus = Qgis::ProcessingModelChildAlgorithmExecutionStatus::NotExecuted;
     QVariantMap mInputs;
     QVariantMap mOutputs;
+    QString mHtmlLog;
 
 };
 

tests/src/analysis/testqgsprocessingmodelalgorithm.cpp

@@ -69,7 +69,7 @@ class DummyRaiseExceptionAlgorithm : public QgsProcessingAlgorithm
     QString displayName() const override { return mName; }
     QVariantMap processAlgorithm( const QVariantMap &, QgsProcessingContext &, QgsProcessingFeedback * ) override
     {
-      throw QgsProcessingException( QString() );
+      throw QgsProcessingException( QStringLiteral( "something bad happened" ) );
     }
     static bool postProcessAlgorithmCalled;
     QVariantMap postProcessAlgorithm( QgsProcessingContext &, QgsProcessingFeedback * ) final
@@ -2330,12 +2330,14 @@ void TestQgsProcessingModelAlgorithm::modelWithChildException()
 
   QgsProcessingModelChildAlgorithm algWhichRaisesException;
   algWhichRaisesException.setChildId( QStringLiteral( "raise" ) );
+  algWhichRaisesException.setDescription( QStringLiteral( "my second step" ) );
   algWhichRaisesException.setAlgorithmId( "dummy4:raise" );
   algWhichRaisesException.setDependencies( {QgsProcessingModelChildDependency( QStringLiteral( "buffer" ) )} );
   m.addChildAlgorithm( algWhichRaisesException );
 
   // run and check context details
   QgsProcessingContext context;
+  context.setLogLevel( Qgis::ProcessingLogLevel::ModelDebug );
   QgsProcessingFeedback feedback;
   QVariantMap params;
   QgsVectorLayer *layer3111 = new QgsVectorLayer( "Point?crs=epsg:3111", "v1", "memory" );
@@ -2359,9 +2361,13 @@ void TestQgsProcessingModelAlgorithm::modelWithChildException()
   QCOMPARE( context.modelChildResults().value( "buffer" ).executionStatus(), Qgis::ProcessingModelChildAlgorithmExecutionStatus::Success );
   QCOMPARE( context.modelChildResults().value( "buffer" ).inputs().value( "INPUT" ).toString(), QStringLiteral( "v1" ) );
   QCOMPARE( context.modelChildResults().value( "buffer" ).inputs().value( "OUTPUT" ).toString(), QStringLiteral( "memory:Buffered" ) );
+  QCOMPARE( context.modelChildResults().value( "buffer" ).htmlLog().left( 50 ), QStringLiteral( "<span style=\"color:#777\">Prepare algorithm: buffer" ) );
+  QCOMPARE( context.modelChildResults().value( "buffer" ).htmlLog().right( 21 ), QStringLiteral( "s (1 output(s)).<br/>" ) );
   QVERIFY( context.temporaryLayerStore()->mapLayer( context.modelChildResults().value( "buffer" ).outputs().value( "OUTPUT" ).toString() ) );
 
   QCOMPARE( context.modelChildResults().value( "raise" ).executionStatus(), Qgis::ProcessingModelChildAlgorithmExecutionStatus::Failed );
+  QCOMPARE( context.modelChildResults().value( "raise" ).htmlLog().left( 49 ), QStringLiteral( "<span style=\"color:#777\">Prepare algorithm: raise" ) );
+  QVERIFY( context.modelChildResults().value( "raise" ).htmlLog().contains( QStringLiteral( "Error encountered while running my second step: something bad happened" ) ) );
 }
 
 void TestQgsProcessingModelAlgorithm::modelDependencies()