Setting up and using Python's logging framework.

It's dubious whether logging.basicConfig() should be called here, so
that call will probably be moved somewhere else.

blender_cloud/__init__.py

@@ -42,6 +42,8 @@ if 'pillar' in locals():
 else:
     from . import pillar, async_loop, gui
 
+import logging
+
 import bpy
 from bpy.types import AddonPreferences, Operator, WindowManager
 from bpy.props import StringProperty
@@ -145,6 +147,8 @@ def register():
         name="Blender Cloud node UUID",
         default='')  # empty == top-level of project
 
+    logging.basicConfig(level=logging.INFO,
+                        format='%(asctime)-15s %(levelname)8s %(name)s %(message)s')
     gui.register()
 
 

blender_cloud/async_loop.py

@@ -2,26 +2,29 @@
 
 import asyncio
 import traceback
+import logging
 
 import bpy
 
+log = logging.getLogger(__name__)
+
 
 def kick_async_loop(*args):
     loop = asyncio.get_event_loop()
 
     if loop.is_closed():
-        print('{}: loop closed, stopping'.format(__name__))
+        log.warning('loop closed, stopping')
         stop_async_loop()
         return
 
     all_tasks = asyncio.Task.all_tasks()
     if not all_tasks:
-        print('{}: no more scheduled tasks, stopping'.format(__name__))
+        log.debug('no more scheduled tasks, stopping')
         stop_async_loop()
         return
 
     if all(task.done() for task in all_tasks):
-        print('{}: all tasks are done, fetching results and stopping.'.format(__name__))
+        log.info('all tasks are done, fetching results and stopping.'.format(__name__))
         for task in all_tasks:
             # noinspection PyBroadException
             try:
@@ -43,6 +46,12 @@ def kick_async_loop(*args):
 
 
 def async_loop_handler() -> callable:
+    """Returns the asynchronous loop handler `kick_async_loop`
+
+    Only returns the function if it is installed as scene_update_pre handler, otherwise
+    it returns None.
+    """
+
     name = kick_async_loop.__name__
     for handler in bpy.app.handlers.scene_update_pre:
         if getattr(handler, '__name__', '') == name:
@@ -61,3 +70,4 @@ def stop_async_loop():
     if handler is None:
         return
     bpy.app.handlers.scene_update_pre.remove(handler)
+    log.debug('stopped async loop.')

blender_cloud/gui.py

@@ -19,7 +19,9 @@
 #
 # ##### END GPL LICENSE BLOCK #####
 import asyncio
+import logging
 import threading
+import traceback
 
 import bpy
 import bgl
@@ -160,6 +162,7 @@ class BlenderCloudBrowser(bpy.types.Operator):
     node_uuid = ''  # Blender Cloud node UUID
     async_task = None  # asyncio task for fetching thumbnails
     timer = None
+    log = logging.getLogger('%s.BlenderCloudBrowser' % __name__)
 
     _menu_item_lock = threading.Lock()
     current_path = ''
@@ -172,11 +175,9 @@ class BlenderCloudBrowser(bpy.types.Operator):
 
     def invoke(self, context, event):
         if context.area.type != 'VIEW_3D':
-            self.report({'WARNING'}, "View3D not found, cannot show asset flinger")
+            self.report({'WARNING'}, "View3D not found, cannot show Blender Cloud browser")
             return {'CANCELLED'}
 
-        print('Area is %s' % context.area)
-
         wm = context.window_manager
         self.thumbnails_cache = wm.thumbnails_cache
         self.project_uuid = wm.blender_cloud_project
@@ -241,10 +242,12 @@ class BlenderCloudBrowser(bpy.types.Operator):
             self.async_task.result()  # This re-raises any exception of the task.
 
     def _finish(self, context):
+        self.log.debug('Finishing the modal operator')
         self._stop_async_task()
         bpy.types.SpaceView3D.draw_handler_remove(self._draw_handle, 'WINDOW')
         context.window_manager.event_timer_remove(self.timer)
         context.area.tag_redraw()
+        self.log.debug('Modal operator finished')
 
     def clear_images(self):
         """Removes all images we loaded from Blender's memory."""

blender_cloud/pillar.py

@@ -2,6 +2,7 @@ import asyncio
 import sys
 import os
 import functools
+import logging
 
 # Add our shipped Pillar SDK wheel to the Python path
 if not any('pillar_sdk' in path for path in sys.path):
@@ -17,6 +18,7 @@ import pillarsdk.exceptions
 import pillarsdk.utils
 
 _pillar_api = None  # will become a pillarsdk.Api object.
+log = logging.getLogger(__name__)
 
 
 class UserNotLoggedInError(RuntimeError):
@@ -75,10 +77,10 @@ async def get_project_uuid(project_url: str) -> str:
     try:
         project = await loop.run_in_executor(None, find_one)
     except pillarsdk.exceptions.ResourceNotFound:
-        print('Project with URL %r does not exist' % project_url)
+        log.error('Project with URL %r does not exist', project_url)
         return None
 
-    print('Found project %r' % project)
+    log.info('Found project %r', project)
     return project['_id']
 
 
@@ -218,10 +220,12 @@ async def parent_node_uuid(node_uuid: str) -> str:
     api = pillar_api()
     loop = asyncio.get_event_loop()
 
+    log.debug('Finding parent node for node %r', node_uuid)
     find_node = functools.partial(pillarsdk.Node.find, node_uuid,
                                   {'projection': {'parent': 1}}, api=api)
     node = await loop.run_in_executor(None, find_node)
     if node is None:
+        log.debug('Unable to find node %r, returning empty parent', node_uuid)
         return ''
 
     print('Found node {}'.format(node))