store path to bcf in Blender file to reaccess it on Blender restart

Previously it was throwing errors if load .bcf and then restart Blender, since it was just trying to reaccess file in BcfStore.bcfxml which is gone after Blender restart. Now we store filepath to bcf in Blender properties to reload it after Blender restart.

Removed BCFProperties.is_loaded as it won't be possible to rely on it after Blender restart - after restart it will still indicate that file is loaded and it won't be possible to change it from .poll and .draw if file is gone.

src/blenderbim/blenderbim/bim/module/bcf/bcfstore.py

@@ -16,6 +16,8 @@
 # You should have received a copy of the GNU General Public License
 # along with BlenderBIM Add-on.  If not, see <http://www.gnu.org/licenses/>.
 
+import os
+import bpy
 import bcf
 import bcf.v2.bcfxml
 
@@ -23,12 +25,31 @@ import bcf.v2.bcfxml
 class BcfStore:
     bcfxml = None
 
-    @staticmethod
+    @classmethod
-    def get_bcfxml():
+    def get_bcfxml(cls):
-        if not BcfStore.bcfxml:
+        if not cls.bcfxml:
-            BcfStore.bcfxml = bcf.v2.bcfxml.BcfXml()
+            bcf_filepath = bpy.context.scene.BCFProperties.bcf_file
-        return BcfStore.bcfxml
+            if not os.path.isabs(bcf_filepath):
+                bcf_filepath = os.path.abspath(os.path.join(bpy.path.abspath("//"), bcf_filepath))
+            if bcf_filepath:
+                try:
+                    cls.bcfxml = bcf.bcfxml.load(bcf_filepath)
+                except:
+                    # there will be a plenty of "Permission denied" errors
+                    # as many poll() methods will try to access the bcfxml simultaneously
+                    # the first time it's loaded
+                    pass
+        return cls.bcfxml
 
     @classmethod
-    def set(cls, bcfxml):
+    def set(cls, bcfxml, filepath):
         cls.bcfxml = bcfxml
+        bpy.context.scene.BCFProperties.bcf_file = filepath
+
+    @classmethod
+    def set_by_filepath(cls, filepath):
+        cls.set(None, filepath)
+
+    @classmethod
+    def unload_bcfxml(cls):
+        cls.set(None, "")

src/blenderbim/blenderbim/bim/module/bcf/operator.py

@@ -42,11 +42,9 @@ class NewBcfProject(bpy.types.Operator):
     bl_options = {"REGISTER", "UNDO"}
 
     def execute(self, context):
-        context.scene.BCFProperties.is_loaded = False
         bcfxml = bcf.v2.bcfxml.BcfXml.create_new("New Project")
-        bcfstore.BcfStore.set(bcfxml)
+        bcfstore.BcfStore.set(bcfxml, "")
         bpy.ops.bim.load_bcf_project()
-        context.scene.BCFProperties.is_loaded = True
         return {"FINISHED"}
 
 
@@ -59,11 +57,10 @@ class LoadBcfProject(bpy.types.Operator):
 
     def execute(self, context):
         if self.filepath:
-            bcfstore.BcfStore.bcfxml = bcf.bcfxml.load(self.filepath)
+            bcfstore.BcfStore.set_by_filepath(self.filepath)
         bcfxml = bcfstore.BcfStore.get_bcfxml()
         context.scene.BCFProperties.name = bcfxml.project.name
         bpy.ops.bim.load_bcf_topics()
-        context.scene.BCFProperties.is_loaded = True
         return {"FINISHED"}
 
     def invoke(self, context, event):
@@ -77,8 +74,7 @@ class UnloadBcfProject(bpy.types.Operator):
     bl_options = {"REGISTER", "UNDO"}
 
     def execute(self, context):
-        bcfstore.BcfStore.set(None)
+        bcfstore.BcfStore.unload_bcfxml()
-        context.scene.BCFProperties.is_loaded = False
         return {"FINISHED"}
 
 
@@ -267,6 +263,7 @@ class SaveBcfProject(bpy.types.Operator):
     def execute(self, context):
         bcfxml = bcfstore.BcfStore.get_bcfxml()
         bcfxml.save(self.filepath)
+        bcfstore.BcfStore.set(bcfxml, self.filepath)
         return {"FINISHED"}
 
     def invoke(self, context, event):

src/blenderbim/blenderbim/bim/module/bcf/prop.py

@@ -41,37 +41,37 @@ def purge():
 
 
 def updateBcfReferenceLink(self, context):
-    if context.scene.BCFProperties.is_loaded:
+    if bcfstore.BcfStore.get_bcfxml():
         bpy.ops.bim.edit_bcf_reference_links()
 
 
 def updateBcfLabel(self, context):
-    if context.scene.BCFProperties.is_loaded:
+    if bcfstore.BcfStore.get_bcfxml():
         bpy.ops.bim.edit_bcf_labels()
 
 
 def updateBcfProjectName(self, context):
-    if self.is_loaded:
+    if bcfstore.BcfStore.get_bcfxml():
         bpy.ops.bim.edit_bcf_project_name()
 
 
 def updateBcfAuthor(self, context):
-    if self.is_loaded:
+    if bcfstore.BcfStore.get_bcfxml():
         bpy.ops.bim.edit_bcf_author()
 
 
 def updateBcfTopicName(self, context):
-    if context.scene.BCFProperties.is_loaded:
+    if bcfstore.BcfStore.get_bcfxml():
         bpy.ops.bim.edit_bcf_topic_name()
 
 
 def updateBcfTopicIsEditable(self, context):
-    if context.scene.BCFProperties.is_loaded and not self.is_editable:
+    if bcfstore.BcfStore.get_bcfxml() and not self.is_editable:
         bpy.ops.bim.edit_bcf_topic()
 
 
 def updateBcfCommentIsEditable(self, context):
-    if context.scene.BCFProperties.is_loaded and not self.is_editable:
+    if bcfstore.BcfStore.get_bcfxml() and not self.is_editable:
         bpy.ops.bim.edit_bcf_comment(comment_guid=self.name)
 
 
@@ -151,7 +151,7 @@ class BcfTopic(PropertyGroup):
 
 
 class BCFProperties(PropertyGroup):
-    is_loaded: BoolProperty(name="Is Loaded", default=False)
+    bcf_file: StringProperty(name="BCF File")
     comment_text_width: IntProperty(name="Comment Text Width", default=40)
     name: StringProperty(default="", name="Project Name", update=updateBcfProjectName)
     author: StringProperty(default="john@doe.com", name="Author Email", update=updateBcfAuthor)

src/blenderbim/blenderbim/bim/module/bcf/ui.py

@@ -39,8 +39,7 @@ class BIM_PT_bcf(Panel):
         scene = context.scene
         props = scene.BCFProperties
 
-
+        if not bcfstore.BcfStore.get_bcfxml():
-        if not props.is_loaded:
             row = layout.row(align=True)
             row.operator("bim.new_bcf_project", text="New Project")
             row.operator("bim.load_bcf_project", text="Load Project")