Catching PipelineStepMethod exception then sharing it to observers before to re-raise it.

3 files changed, 18 insertions, 5 deletions

diff --git a/src/argaze/DataFeatures.py b/src/argaze/DataFeatures.py
index 6da769d..7ac6a4b 100644
--- a/src/argaze/DataFeatures.py
+++ b/src/argaze/DataFeatures.py
@@ -9,6 +9,8 @@ __license__ = "BSD"
 
 from typing import TypeVar, Tuple, Any
 import os
+import sys
+import traceback
 import importlib
 from inspect import getmembers, getmodule
 import collections
@@ -679,12 +681,18 @@ def PipelineStepMethod(method):
 
         # Initialize execution time assessment
         start = time.perf_counter()
+        exception = None
+        result = None
         
         try:
 
             # Execute wrapped method
             result = method(self, timestamp, *args, **kw)
 
+        except Exception as e:
+
+            exception = e
+
         finally:
 
             # Measure execution time
@@ -701,7 +709,12 @@ def PipelineStepMethod(method):
                 subscription = getattr(observer, subscription_name)
 
                 # Call subscription
-                subscription(timestamp, self)
+                subscription(timestamp, self, exception)
+
+        # Raise exception
+        if exception is not None:
+
+            raise exception
 
         return result
 
@@ -711,7 +724,7 @@ class PipelineStepObserver():
     """Define abstract class to observe pipeline step object use.
 
     !!! note
-        To subscribe to a method call, the inherited class simply needs to define 'on_<method_name>' functions with timestamp and object argument.
+        To subscribe to a method call, the inherited class simply needs to define 'on_<method_name>' functions with timestamp, object and traceback argument.
     """
 
     def __enter__(self):
diff --git a/src/argaze/utils/demo_data/demo_frame_logger.py b/src/argaze/utils/demo_data/demo_frame_logger.py
index 025d4d8..64dbf96 100644
--- a/src/argaze/utils/demo_data/demo_frame_logger.py
+++ b/src/argaze/utils/demo_data/demo_frame_logger.py
@@ -12,7 +12,7 @@ from argaze.utils import UtilsFeatures
 
 class FixationLogger(DataFeatures.PipelineStepObserver, UtilsFeatures.FileWriter):
 
-	def on_look(self, timestamp, frame):
+	def on_look(self, timestamp, frame, exception):
 		"""Log fixations."""
 
 		# Log fixations
@@ -29,7 +29,7 @@ class FixationLogger(DataFeatures.PipelineStepObserver, UtilsFeatures.FileWriter
 
 class ScanPathAnalysisLogger(DataFeatures.PipelineStepObserver, UtilsFeatures.FileWriter):
 
-	def on_look(self, timestamp, frame):
+	def on_look(self, timestamp, frame, exception):
 		"""Log scan path metrics."""
 
 		if frame.analysis_available:
diff --git a/src/argaze/utils/demo_data/demo_layer_logger.py b/src/argaze/utils/demo_data/demo_layer_logger.py
index 1e78375..47cf577 100644
--- a/src/argaze/utils/demo_data/demo_layer_logger.py
+++ b/src/argaze/utils/demo_data/demo_layer_logger.py
@@ -12,7 +12,7 @@ from argaze.utils import UtilsFeatures
 
 class AOIScanPathAnalysisLogger(DataFeatures.PipelineStepObserver, UtilsFeatures.FileWriter):
 
-	def on_look(self, timestamp, layer):
+	def on_look(self, timestamp, layer, exception):
 		"""Log aoi scan path metrics"""
 
 		if layer.analysis_available: