Add optional property for locations

cartridges/importer/flatpak_source.py

@@ -36,8 +36,9 @@ class FlatpakSourceIterable(SourceIterable):
         """Generator method producing games"""
 
         icon_theme = Gtk.IconTheme.new()
+        if user_data := self.source.locations.user_data["icons"]:
+            icon_theme.add_search_path(str(user_data))
         icon_theme.add_search_path(str(self.source.locations.system_data["icons"]))
-        icon_theme.add_search_path(str(self.source.locations.user_data["icons"]))
 
         blacklist = (
             {"hu.kramo.Cartridges", "hu.kramo.Cartridges.Devel"}
@@ -154,5 +155,6 @@ class FlatpakSource(ExecutableFormatSource):
                     "icons": LocationSubPath("exports/share/icons", True),
                 },
                 invalid_subtitle=Location.DATA_INVALID_SUBTITLE,
+                optional=True,
             ),
         )

cartridges/importer/location.py

@@ -16,7 +16,8 @@ class LocationSubPath(NamedTuple):
 
 
 class UnresolvableLocationError(Exception):
-    pass
+    def __init__(self, optional):
+        self.optional = optional
 
 
 class Location:
@@ -49,12 +50,14 @@ class Location:
         candidates: Iterable[Candidate],
         paths: Mapping[str, LocationSubPath],
         invalid_subtitle: str,
+        optional: Optional[bool] = False,
     ) -> None:
         super().__init__()
         self.schema_key = schema_key
         self.candidates = candidates
         self.paths = paths
         self.invalid_subtitle = invalid_subtitle
+        self.optional = optional
 
     def check_candidate(self, candidate: Path) -> bool:
         """Check if a candidate root has the necessary files and directories"""
@@ -87,7 +90,7 @@ class Location:
             break
         else:
             # No good candidate found
-            raise UnresolvableLocationError()
+            raise UnresolvableLocationError(self.optional)
 
         # Update the schema with the found candidate
         value = str(candidate)
@@ -96,7 +99,13 @@ class Location:
 
     def __getitem__(self, key: str) -> Optional[Path]:
         """Get the computed path from its key for the location"""
-        self.resolve()
+        try:
+            self.resolve()
+        except UnresolvableLocationError as error:
+            if error.optional:
+                return None
+            raise UnresolvableLocationError from error
+
         if self.root:
             return self.root / self.paths[key].segment
         return None

cartridges/importer/source.py

@@ -23,7 +23,7 @@ from collections.abc import Iterable
 from typing import Any, Collection, Generator, Optional
 
 from cartridges.game import Game
-from cartridges.importer.location import Location
+from cartridges.importer.location import Location, UnresolvableLocationError
 
 # Type of the data returned by iterating on a Source
 SourceIterationResult = Optional[Game | tuple[Game, tuple[Any]]]
@@ -87,10 +87,15 @@ class Source(Iterable):
     def __iter__(self) -> Generator[SourceIterationResult, None, None]:
         """
         Get an iterator for the source
-        :raises UnresolvableLocationError: Not iterable if any of the locations are unresolvable
+        :raises UnresolvableLocationError: Not iterable
+        if any of the mandatory locations are unresolvable
         """
         for location in self.locations:
-            location.resolve()
+            try:
+                location.resolve()
+            except UnresolvableLocationError as error:
+                if not error.optional:
+                    raise UnresolvableLocationError from error
         return iter(self.iterable_class(self))