Skeleton for autostorage extension

openflexure_microscope/api/default_extensions/__init__.py

@@ -4,6 +4,7 @@ import traceback
 from .autofocus import autofocus_extension_v2
 from .scan import scan_extension_v2
 from .zip_builder import zip_extension_v2
+from .autostorage import autostorage_extension_v2
 
 # "Gracefully" handle cases where picamera cannot be imported (eg test server)
 try:

openflexure_microscope/api/default_extensions/autostorage.py

@@ -0,0 +1,37 @@
+from labthings.server.extensions import BaseExtension
+from openflexure_microscope.paths import settings_file_path
+from openflexure_microscope.config import OpenflexureSettingsFile
+
+import logging
+
+AS_SETTINGS_PATH = settings_file_path("autostorage_settings.json")
+
+
+class AutostorageExtension(BaseExtension):
+    def __init__(self):
+        BaseExtension.__init__(
+            self,
+            "org.openflexure.autostorage",
+            version="2.0.0-beta.1",
+            description="Handle switching capture storage devices",
+        )
+
+        self.settings = OpenflexureSettingsFile(
+            AS_SETTINGS_PATH, defaults={"preferred": None}
+        )
+
+        # We'll store a reference to a camera object, who's capture paths will be modified
+        self.camera = None
+
+        # Register the on_microscope function to run when the microscope is attached
+        self.on_component("org.openflexure.microscope", self.on_microscope)
+
+    def on_microscope(self, microscope_obj):
+        """Function to automatically call when the parent LabThing has a microscope attached."""
+        logging.debug(f"Autostorage extension found microscope {microscope_obj}")
+        if hasattr(microscope_obj, "camera"):
+            self.camera = microscope_obj.camera
+            logging.debug(f"Autostorage extension bound to camera {self.camera}")
+
+
+autostorage_extension_v2 = AutostorageExtension()

openflexure_microscope/config.py

@@ -32,7 +32,8 @@ class OpenflexureSettingsFile:
         self.path = path
 
         # Initialise basic config file with defaults if it doesn't exist
-        initialise_file(self.path, populate=defaults)
+        defaults_str = json.dumps(defaults, cls=JSONEncoder, indent=2, sort_keys=True)
+        initialise_file(self.path, populate=defaults_str)
 
     def load(self) -> dict:
         """