WIP: Pseudocode example of adding a logging.config.dictConfig cli argument

This lets you easily load a custom logging configuration including handlers

Author: MHendricks

preditor/cli.py

@@ -1,6 +1,7 @@
 from __future__ import absolute_import
 
 import logging
+import logging.config
 import sys
 from distutils.spawn import find_executable
 
@@ -35,13 +36,25 @@ def get_app_id(name, is_default):
     default_if_no_args=True,
     context_settings=CONTEXT_SETTINGS,
 )
-def cli():
+@click.option(
+    "--logging-cfg",
+    # Note: Using eager makes it so logging is configured as early as possible
+    # based on this argument.
+    is_eager=True,
+    type=click.Path(file_okay=True, resolve_path=True),
+    envvar='PREDITOR_LOGGING_CFG',
+    help="Path to json file defining a logging configuration based on "
+    "logging.config.dictConfig. If not specified the preditor prefs are used."
+    "If the env var PREDITOR_LOGGING_CFG is set it will use that value.",
+)
+def cli(logging_config):
     """PrEditor is a Qt based python console and code editor. It runs in many
     DCC's like Maya, Houdini, Nuke, and 3ds Max.
 
     To see help for launching the PrEditor gui, use `preditor launch -h`.
     """
-    pass
+    if logging_config is not None:
+        preditor.config.logging_cfg = logging_config
 
 
 # launch

preditor/config.py

@@ -1,5 +1,6 @@
 from __future__ import absolute_import
 
+import json
 import logging
 from functools import wraps
 
@@ -47,6 +48,7 @@ def __init__(self):
         self._locks = {}
         self._name = None
         self._logging = False
+        self._logging_cfg = None
         self._headless_callback = None
         self._on_create_callback = None
         self._parent_callback = None
@@ -62,6 +64,7 @@ def dump(self, indent=0):
             f"{' ' * indent}excepthooks: {self.excepthooks!r}",
             f"{' ' * indent}error_dialog_class: {self.error_dialog_class!r}",
             f"{' ' * indent}logging: {self.logging}",
+            f"{' ' * indent}logging_cfg: {self.logging_cfg}",
             f"{' ' * indent}headless_callback: {self.headless_callback!r}",
             f"{' ' * indent}parent_callback: {self.parent_callback!r}",
             f"{' ' * indent}on_create_callback: {self.on_create_callback!r}",
@@ -216,6 +219,27 @@ def logging(self, state):
         self._logging = state
         self.update_logging()
 
+    @property
+    def logging_cfg(self):
+        """If set use this json file to configure logging instead of preditor prefs.
+
+        This can be used to load handlers and other customization's. Using this
+        disables saving of the logging configuration to user prefs.
+        """
+        return self._logging_cfg
+
+    @logging_cfg.setter
+    def logging_cfg(self, logging_cfg):
+        # TODO: if this is not None then it should disable saving of the logging prefs
+        # TODO: Should this use @set_if_unlocked() to disable updating?
+        # TODO: Should we add some shortcuts to files stored in the logging_cfgs dir?
+        # For example: "preditor\resource\logging_cfgs\default_cfg.json"
+        self._logging_cfg = logging_cfg
+        with open(logging_cfg) as fle:
+            cfg = json.load(fle)
+            logging.config.dictConfig(cfg)
+        self.update_logging()
+
     @property
     def name(self):
         """The name to use for the global instance of PrEditor.

preditor/resource/logging_cfgs/default_cfg.json

@@ -0,0 +1,22 @@
+{
+    "version": 1,
+    "disable_existing_loggers": false,
+    "formatters": {
+        "standard": {
+            "format": "%(name)s - %(levelname)s - %(message)s"
+        }
+    },
+    "handlers": {
+        "console": {
+            "class": "logging.StreamHandler",
+            "formatter": "standard",
+            "stream": "ext://sys.stdout"
+        }
+    },
+    "loggers": {
+        "": {
+            "handlers": ["console"],
+            "propagate": true
+        }
+    }
+}