Core: hot reload components from installed apworld (#3480)

* Core: hot reload components from installed apworld

* address PR reviews

`Launcher` widget members default to `None` so they can be defined in `build`

`Launcher._refresh_components` is not wrapped

loaded world goes into `world_sources` so we can check if it's already loaded.
(`WorldSource` can be ordered now without trying to compare `None` and `float`)
(don't load empty directories so we don't detect them as worlds)

* clarify that the installation is successful

worlds/LauncherComponents.py

@@ -1,3 +1,4 @@
+import bisect
 import logging
 import pathlib
 import weakref
@@ -94,9 +95,10 @@ def _install_apworld(apworld_src: str = "") -> Optional[Tuple[pathlib.Path, path
 
     apworld_path = pathlib.Path(apworld_src)
 
+    module_name = pathlib.Path(apworld_path.name).stem
     try:
         import zipfile
-        zipfile.ZipFile(apworld_path).open(pathlib.Path(apworld_path.name).stem + "/__init__.py")
+        zipfile.ZipFile(apworld_path).open(module_name + "/__init__.py")
     except ValueError as e:
         raise Exception("Archive appears invalid or damaged.") from e
     except KeyError as e:
@@ -107,6 +109,9 @@ def _install_apworld(apworld_src: str = "") -> Optional[Tuple[pathlib.Path, path
         raise Exception("Custom Worlds directory appears to not be writable.")
     for world_source in worlds.world_sources:
         if apworld_path.samefile(world_source.resolved_path):
+            # Note that this doesn't check if the same world is already installed.
+            # It only checks if the user is trying to install the apworld file
+            # that comes from the installation location (worlds or custom_worlds)
             raise Exception(f"APWorld is already installed at {world_source.resolved_path}.")
 
     # TODO: run generic test suite over the apworld.
@@ -116,6 +121,22 @@ def _install_apworld(apworld_src: str = "") -> Optional[Tuple[pathlib.Path, path
     import shutil
     shutil.copyfile(apworld_path, target)
 
+    # If a module with this name is already loaded, then we can't load it now.
+    # TODO: We need to be able to unload a world module,
+    # so the user can update a world without restarting the application.
+    found_already_loaded = False
+    for loaded_world in worlds.world_sources:
+        loaded_name = pathlib.Path(loaded_world.path).stem
+        if module_name == loaded_name:
+            found_already_loaded = True
+            break
+    if found_already_loaded:
+        raise Exception(f"Installed APWorld successfully, but '{module_name}' is already loaded,\n"
+                        "so a Launcher restart is required to use the new installation.")
+    world_source = worlds.WorldSource(str(target), is_zip=True)
+    bisect.insort(worlds.world_sources, world_source)
+    world_source.load()
+
     return apworld_path, target
 
 

worlds/__init__.py

@@ -1,11 +1,12 @@
 import importlib
+import logging
 import os
 import sys
 import warnings
 import zipimport
 import time
 import dataclasses
-from typing import Dict, List, TypedDict, Optional
+from typing import Dict, List, TypedDict
 
 from Utils import local_path, user_path
 
@@ -48,7 +49,7 @@ class WorldSource:
     path: str  # typically relative path from this module
     is_zip: bool = False
     relative: bool = True  # relative to regular world import folder
-    time_taken: Optional[float] = None
+    time_taken: float = -1.0
 
     def __repr__(self) -> str:
         return f"{self.__class__.__name__}({self.path}, is_zip={self.is_zip}, relative={self.relative})"
@@ -92,7 +93,6 @@ class WorldSource:
             print(f"Could not load world {self}:", file=file_like)
             traceback.print_exc(file=file_like)
             file_like.seek(0)
-            import logging
             logging.exception(file_like.read())
             failed_world_loads.append(os.path.basename(self.path).rsplit(".", 1)[0])
             return False
@@ -107,7 +107,11 @@ for folder in (folder for folder in (user_folder, local_folder) if folder):
         if not entry.name.startswith(("_", ".")):
             file_name = entry.name if relative else os.path.join(folder, entry.name)
             if entry.is_dir():
-                world_sources.append(WorldSource(file_name, relative=relative))
+                init_file_path = os.path.join(entry.path, '__init__.py')
+                if os.path.isfile(init_file_path):
+                    world_sources.append(WorldSource(file_name, relative=relative))
+                else:
+                    logging.warning(f"excluding {entry.name} from world sources because it has no __init__.py")
             elif entry.is_file() and entry.name.endswith(".apworld"):
                 world_sources.append(WorldSource(file_name, is_zip=True, relative=relative))