bcf - fix issues with unexpected reloads from zip

It wasn't considering that self._topics could be an empty dict because there are no topics and it would also reload it. Now we have None value to distinguish when it actually wasn't loaded before.

Same for viewpoints, reference files and document references.

I've also imade mplementations identical/more similar between v2 and v3.

src/bcf/bcf/v2/bcfxml.py

@@ -24,7 +24,7 @@ class BcfXml:
         self._xml_handler = xml_handler or XmlParserSerializer()
         self._version: Optional[mdl.Version] = None
         self._project_info: Optional[mdl.ProjectExtension] = None
-        self._topics: dict[str, TopicHandler] = {}
+        self._topics: Optional[dict[str, TopicHandler]] = None
         self._extension_schema: Optional[bytes] = None
         self._zip_file = self._load_zip_file()
 
@@ -88,21 +88,21 @@ class BcfXml:
     @property
     def topics(self) -> dict[str, TopicHandler]:
         """BCF topics."""
-        if not self._topics and self._zip_file:
+        if self._topics is None:
-            self._topics = self._load_topics(self._zip_file, self._xml_handler)
+            self._topics = self._load_topics()
         return self._topics
 
-    def _load_topics(
+    def _load_topics(self) -> dict[str, TopicHandler]:
-        self, zip_file: zipfile.ZipFile, xml_handler: AbstractXmlParserSerializer
-    ) -> dict[str, TopicHandler]:
         topics = {}
-        for topic_dir in zipfile.Path(zip_file).iterdir():
+        if self._zip_file is None:
+            return topics
+        for topic_dir in zipfile.Path(self._zip_file).iterdir():
             if not topic_dir.is_dir():
                 continue
             markup_path = topic_dir.joinpath("markup.bcf")
             if not markup_path.exists():
                 continue
-            topics[topic_dir.name] = TopicHandler(topic_dir, xml_handler)
+            topics[topic_dir.name] = TopicHandler(topic_dir, self._xml_handler)
         return topics
 
     @classmethod

src/bcf/bcf/v2/topic.py

@@ -27,9 +27,9 @@ class TopicHandler:
         xml_handler: Optional[AbstractXmlParserSerializer] = None,
     ) -> None:
         self._markup: Optional[mdl.Markup] = None
-        self._viewpoints: dict[str, VisualizationInfoHandler] = {}
+        self._viewpoints: Optional[dict[str, VisualizationInfoHandler]] = None
-        self._reference_files: dict[str, bytes] = {}
+        self._reference_files: Optional[dict[str, bytes]] = None
-        self._document_references: dict[str, bytes] = {}
+        self._document_references: Optional[dict[str, bytes]] = None
         self._bim_snippet: Optional[bytes] = None
         self._xml_handler = xml_handler or XmlParserSerializer()
         self._topic_dir = topic_dir
@@ -80,14 +80,24 @@ class TopicHandler:
 
     @property
     def viewpoints(self) -> dict[str, VisualizationInfoHandler]:
-        if not self._viewpoints and self._topic_dir:
+        if self._viewpoints is None:
             self._viewpoints = self._load_viewpoints()
         return self._viewpoints
 
+    def _load_viewpoints(self) -> dict[str, VisualizationInfoHandler]:
+        if self._topic_dir and self.markup and (viewpoints := self.markup.viewpoints):
+            return VisualizationInfoHandler.from_topic_viewpoints(self._topic_dir, viewpoints)
+        return {}
+
     @property
     def reference_files(self) -> dict[str, bytes]:
-        if self._reference_files or not self.header:
+        if self._reference_files is not None:
             return self._reference_files
+
+        self._reference_files = {}
+        if not self.header:
+            return self._reference_files
+
         for ref in self.header.file:
             if ref.is_external:
                 continue
@@ -99,8 +109,13 @@ class TopicHandler:
 
     @property
     def document_references(self) -> dict[str, bytes]:
-        if self._document_references or not self.topic:
+        if self._document_references is not None:
             return self._document_references
+
+        self._document_references = {}
+        if not self.topic:
+            return self._document_references
+
         for doc in self.topic.document_reference:
             if doc.is_external or not doc.referenced_document:
                 continue
@@ -118,11 +133,6 @@ class TopicHandler:
                 return bim_snippet_path.read_bytes()
         return None
 
-    def _load_viewpoints(self) -> dict[str, VisualizationInfoHandler]:
-        if self.markup and (viewpoints := self.markup.viewpoints):
-            return VisualizationInfoHandler.from_topic_viewpoints(self._topic_dir, viewpoints)
-        return {}
-
     @classmethod
     def create_new(
         cls,

src/bcf/bcf/v3/bcfxml.py

@@ -26,7 +26,7 @@ class BcfXml:
         self._version: Optional[mdl.Version] = None
         self._project_info: Optional[mdl.ProjectInfo] = None
         self._extensions: Optional[mdl.Extensions] = None
-        self._topics: dict[str, TopicHandler] = {}
+        self._topics: Optional[dict[str, TopicHandler]] = None
         self._documents: Optional[DocumentsHandler] = None
         self._zip_file = self._load_zip_file()
 
@@ -91,18 +91,22 @@ class BcfXml:
     @property
     def topics(self) -> dict[str, TopicHandler]:
         """BCF topics."""
-        if not self._topics and self._zip_file:
+        if self._topics is None:
-            self._load_topics()
+            self._topics = self._load_topics()
         return self._topics
 
-    def _load_topics(self) -> None:
+    def _load_topics(self) -> dict[str, TopicHandler]:
+        topics = {}
+        if self._zip_file is None:
+            return topics
         for topic_dir in zipfile.Path(self._zip_file).iterdir():
             if not topic_dir.is_dir():
                 continue
             markup_path = topic_dir.joinpath("markup.bcf")
             if not markup_path.exists():
                 continue
-            self._topics[topic_dir.name] = TopicHandler(topic_dir, self._xml_handler)
+            topics[topic_dir.name] = TopicHandler(topic_dir, self._xml_handler)
+        return topics
 
     @property
     def documents(self) -> Optional[DocumentsHandler]:

src/bcf/bcf/v3/topic.py

@@ -26,7 +26,7 @@ class TopicHandler:
         xml_handler: Optional[AbstractXmlParserSerializer] = None,
     ) -> None:
         self._markup: Optional[mdl.Markup] = None
-        self._viewpoints: dict[str, VisualizationInfoHandler] = {}
+        self._viewpoints: Optional[dict[str, VisualizationInfoHandler]] = None
         self._bim_snippet: Optional[bytes] = None
         self._xml_handler = xml_handler or XmlParserSerializer()
         self._topic_dir = topic_dir
@@ -77,15 +77,15 @@ class TopicHandler:
 
     @property
     def viewpoints(self) -> dict[str, "VisualizationInfoHandler"]:
-        if (
+        if self._viewpoints is None:
-            not self._viewpoints
+            self._viewpoints = self._load_viewpoints()
-            and self._topic_dir
-            and self.topic.viewpoints
-            and (viewpoints := self.topic.viewpoints.view_point)
-        ):
-            self._viewpoints = VisualizationInfoHandler.from_topic_viewpoints(self._topic_dir, viewpoints)
         return self._viewpoints
 
+    def _load_viewpoints(self) -> dict[str, "VisualizationInfoHandler"]:
+        if self._topic_dir and self.topic.viewpoints and (viewpoints := self.topic.viewpoints.view_point):
+            return VisualizationInfoHandler.from_topic_viewpoints(self._topic_dir, viewpoints)
+        return {}
+
     def _load_bim_snippet(self) -> Optional[bytes]:
         bim_snippet_obj = self.topic.bim_snippet
         if bim_snippet_obj and not bim_snippet_obj.is_external and self._topic_dir: