[app][cli] Ensure saved config file can be loaded

Introduce new explicit config option for scan-only. Fixes #240.

Author: Breakthrough

docs/changelog.md

@@ -14,6 +14,11 @@ Fixes issue with application not loading config files saved with v1.8.
 #### Changelog
 
  * [general] Add `--ignore-user-config` flag to both `dvr-scan` and `dvr-scan-app` commands to allow the application to run even if the user config file is corrupted
+ * [general] Add new `scan-only` config option to match the UI checkbox and the `--scan-only` CLI flag
+ * [bugfix] Fix crash on startup when trying to load user config saved with v1.8 [#240](https://github.com/Breakthrough/DVR-Scan/issues/240)
+    * This was caused by the `scan-only` UI option being emitted but the config file did not support it in v1.8
+    * Users who are running into this issue should be able to run DVR-Scan after updating to v1.8.1
+    * As a workaround for previous versions, you can manually remove the `scan-only` line in the saved config file
 
 
 ### 1.8 (August 23, 2025)

dvr_scan/app/__main__.py

@@ -139,7 +139,7 @@ def main():
         args = get_cli_parser().parse_args()
         if args.ignore_user_config:
             config_load_error = None
-            user_config = ConfigRegistry()
+            config = ConfigRegistry()
         init_logging(args, config)
         init_log += [(logging.INFO, "DVR-Scan Application %s" % dvr_scan.__version__)]
         if config_load_error and not hasattr(args, "config"):

dvr_scan/app/application.py

@@ -1364,7 +1364,8 @@ def save(self, settings: ScanSettings) -> ScanSettings:
         return settings
 
     def load(self, settings: ScanSettings):
-        if OutputMode[settings.get("output-mode").upper()] == OutputMode.SCAN_ONLY:
+        output_mode = OutputMode[settings.get("output-mode").upper()]
+        if settings.get("scan-only") or output_mode == OutputMode.SCAN_ONLY:
             self.scan_only = True
         self.open_on_completion = settings.get("open-output-dir")
 
@@ -1669,13 +1670,13 @@ def _get_settings(self) -> ty.Optional[ScanSettings]:
         settings = self._output_area.save(settings)
         settings = self._scan_area.save(settings)
 
-        # Check if we are going to create any output files.
-        # *NOTE*: Depending on the user's settings, we may generate output files even in scan-only
-        # mode (e.g. if the user is generating a mask file).
+        output_mode = (
+            OutputMode.SCAN_ONLY if settings.get("scan-only") else settings.get("output-mode")
+        )
+        # Check if we are going to create any output files. We will create files as long as we're
+        # not in scan-only mode, or if we
         if not settings.get("output-dir") and (
-            not settings.get("scan-only")
-            or settings.get("mask-output")
-            or self._output_area.combine
+            output_mode != OutputMode.SCAN_ONLY or settings.get("mask-output")
         ):
             # We will create files but an output directory wasn't set ahead of time - prompt the
             # user to select one.

dvr_scan/config.py

@@ -329,6 +329,7 @@ def from_config(config_value: str, default: "RGBValue") -> "RGBValue":
     "open-output-dir": True,
     "output-mode": "opencv",
     "region-editor": False,
+    "scan-only": False,
     # Motion Events
     "min-event-length": TimecodeValue("0.1s"),
     "time-before-event": TimecodeValue("1.5s"),

dvr_scan/controller.py

@@ -88,7 +88,7 @@ def parse_settings() -> ty.Optional[ScanSettings]:
         args = get_cli_parser(config).parse_args()
         if args.ignore_user_config:
             config_load_error = None
-            user_config = ConfigRegistry()
+            config = ConfigRegistry()
         debug_mode = args.debug
         init_logging(args=args, config=config)
         init_log += [(logging.INFO, "DVR-Scan %s" % dvr_scan.__version__)]

dvr_scan/scanner.py

@@ -349,6 +349,7 @@ def set_output(
             KeyError:
              - output_mode does not exist in OutputMode
         """
+        print(output_mode)
         if output_dir:
             if comp_file and comp_file.is_absolute():
                 raise ValueError("output file cannot be absolute path if output directory is set!")

dvr_scan/shared/__init__.py

@@ -125,16 +125,16 @@ def init_scanner(
     )
 
     output_dir = settings.get("output-dir")
+    comp_file = settings.get_arg(
+        "output",
+    )
+    mask_file = settings.get_arg("mask-output")
+    output_mode = OutputMode.SCAN_ONLY if settings.get("scan-only") else settings.get("output-mode")
+
     scanner.set_output(
-        comp_file=Path(settings.get("output", ignore_config=True))
-        if settings.get("output", ignore_config=True)
-        else None,
-        mask_file=Path(settings.get_arg("mask-output"))
-        if settings.get_arg("mask-output")
-        else None,
-        output_mode=OutputMode.SCAN_ONLY
-        if settings.get_arg("scan-only")
-        else settings.get("output-mode"),
+        comp_file=Path(comp_file) if comp_file else None,
+        mask_file=Path(mask_file) if mask_file else None,
+        output_mode=output_mode,
         opencv_fourcc=settings.get("opencv-codec"),
         ffmpeg_input_args=settings.get("ffmpeg-input-args"),
         ffmpeg_output_args=settings.get("ffmpeg-output-args"),

dvr_scan/shared/settings.py

@@ -40,16 +40,14 @@ def get_arg(self, option: str) -> ty.Optional[ty.Any]:
         arg_name = option.replace("-", "_")
         return getattr(self._args, arg_name) if hasattr(self._args, arg_name) else None
 
-    def get(self, option: str, ignore_config: bool = False) -> ty.Union[str, int, float, bool]:
+    def get(self, option: str) -> ty.Union[str, int, float, bool]:
         """Get the current value for `option`, preferring the current UI or CLI setting, falling
         back to either the config file option, or the default value."""
         if option in self._app_settings:
             return self._app_settings[option]
         arg_val = self.get_arg(option)
         if arg_val is not None:
             return arg_val
-        if ignore_config:
-            return None
         return self._config.get(option)
 
     def set(self, option: str, value: ty.Union[str, int, float, bool]):

tests/test_cli.py

@@ -42,7 +42,7 @@
     "0",
     "--threshold",
     "0.2",
-    "--ignore-user-config"
+    "--ignore-user-config",
 ]
 BASE_COMMAND_NUM_EVENTS = 3