Some stuff from old exception-based error handling approach

blender_common.py

@@ -10,12 +10,17 @@ from . import bpackage as bpkg
 
 class RepositoryProperty(PropertyGroup):
     url = bpy.props.StringProperty(name="URL")
-    # status = bpy.props.EnumProperty(name="Status")
+    status = bpy.props.EnumProperty(name="Status", items=[
+            ("OK",        "Okay",              "FILE_TICK"),
+            ("NOTFOUND",  "Not found",         "ERROR"),
+            ("NOCONNECT", "Could not connect", "QUESTION"),
+            ])
 
 
 class PACKAGE_UL_repositories(UIList):
     def draw_item(self, context, layout, data, item, icon, active_data, active_propname):
         split = layout.split(0.3)
+        split.label(item.status)
         split.prop(item, "name")
         split.prop(item, "url")
 
@@ -42,29 +47,34 @@ class PackagePreferences(AddonPreferences):
 
 @subprocess_operator
 class PACKAGE_OT_refresh(Operator):
-    """
-    Operator which checks for updates to known package lists
-    """
+    """Check for new and updated packages"""
     bl_idname = "package.refresh"
-    bl_label = "Refresh package list(s)"
+    bl_label = "Refresh Packages"
 
     log = logging.getLogger(__name__)
 
     def invoke(self, context, event):
         prefs = context.user_preferences.addons[__package__].preferences
 
-        if 'repositories' not in prefs:
+        if 'repositories' not in prefs or len(prefs['repositories']) <= 0:
+            self.log.debug(prefs)
+            self.report({'WARNING'}, "No respositories to refresh")
             return {'FINISHED'}
 
-        # HACK: just do the active repo for now
+        # HACK: just use the active repo until we do multi-repo support
         repo = bpkg.Repository(prefs['repositories'][prefs.active_repository].to_dict())
 
         self.proc_kwargs = {'target': subprocess_function(repo.refresh, pipe=self.pipe)}
 
+        return {'RUNNING_MODAL'}
+        
     def modal(self, context, event):
-        # try:
+        try:
             self.poll_subprocess()
-        # except:
+        except bpkg.repository.MissingURLError:
+            self.report({'WARNING'}, "No URL specified")
+
+            
         return {'RUNNING_MODAL'}
 
     def handle_response(self, resp):

bpackage/repository.py

@@ -10,7 +10,19 @@ import json
 import logging
 
 log = logging.getLogger(__name__)
+# log.level = logging.DEBUG
 
+class RepositoryError(Exception):
+    """
+    Superclass for repository-related exceptions
+    """
+
+class MissingURLError(RepositoryError):
+    """
+    Thrown when the repository needs a URL but doesn't have one
+    """
+
+# class RepositoryNotFound(
 
 class Package:
     """
@@ -53,6 +65,12 @@ class Repository:
         Requests repo.json from URL and embeds etag/last-modification headers
         """
 
+        log.debug(self.url)
+        if self.url is None:
+            raise MissingURLError("Cannot refresh repository without a URL")
+
+
+        log.debug("Refreshing repository from %s", self.url)
         req_headers = {}
 
         # Do things this way to avoid adding empty objects/None to the req_headers dict
@@ -110,19 +128,4 @@ class Repository:
             json.dump(self.to_dict(), repo_file, indent=4, sort_keys=True)
         log.info("repo.json written to %s" % path)
 
-# def fetch_repo(url: str, repo: Repository) -> dict:
-def refresh(url):
-    # we have to explicitly close the end of the pipe we are NOT using,
-    # otherwise no exception will be generated when the other process closes its end.
-    pipe[0].close()
-
-    local_repo_path = Path(__file__).parent / 'packages'
-    local_repo_path.mkdir(exist_ok=True)
-
-    try:
-        fetch_repojson(url)
-        pipe[1].send(re.status_code)
-    finally:
-        pipe[1].close()
-
 

subprocess_adapter.py

@@ -44,7 +44,13 @@ def subprocess_operator(cls: Operator, polling_interval=.01) -> Operator:
             # and the pipe is needed for the subprocess_function decorator.
             # TODO: Perhaps this responsibility should be handled here instead (simplifies things but looses some flexibility)
 
-            orig_invoke(self, context, event)
+            orig_ret = orig_invoke(self, context, event)
+
+            # HACK to allow early exits.
+            # Perhaps subprocess_operators should define separately named methods, to avoid confusing mixing semantics in return types
+            if not orig_ret.issubset({'RUNNING_MODAL'}):
+                log.debug('Exiting early')
+                return orig_ret
 
             self.proc = Process(
                     *getattr(self, 'proc_args', []),
@@ -66,7 +72,7 @@ def subprocess_operator(cls: Operator, polling_interval=.01) -> Operator:
         """
         Check the pipe for new messages (nonblocking). If there is a new message, call the callback
         """
-        self.log.debug("polling")
+        log.debug("polling")
         try:
             if self.pipe[0].poll():
                 resp = self.pipe[0].recv()
@@ -74,7 +80,7 @@ def subprocess_operator(cls: Operator, polling_interval=.01) -> Operator:
             else:
                 resp = None
         except EOFError:
-            self.log.debug("done polling")
+            log.debug("done polling")
             return {'FINISHED'}
 
         if resp is not None: