Add more comments about source parsing

core/lib/parsing.py

@@ -98,6 +98,7 @@ def parse_source(user, query_params, raise_error=False):
     if "source" in query_params:
         source = query_params["source"]
 
+        # Validate permissions for restricted sources
         if source in settings.SOURCES_RESTRICTED:
             if not user.has_perm("core.restricted_sources"):
                 message = f"Access denied: {source}"
@@ -105,6 +106,8 @@ def parse_source(user, query_params, raise_error=False):
                     raise QueryError(message)
                 message_class = "danger"
                 return {"message": message, "class": message_class}
+
+        # Check validity of source
         elif source not in settings.MAIN_SOURCES:
             message = f"Invalid source: {source}"
             if raise_error:
@@ -118,11 +121,17 @@ def parse_source(user, query_params, raise_error=False):
     if source:
         sources = [source]
     else:
+        # Here we need to populate what "all" means for the user.
+        # They may only have access to a subset of the sources.
+        # We build a custom source list with ones they have access
+        # to, and then remove "all" from the list.
         sources = list(settings.MAIN_SOURCES)
         if user.has_perm("core.restricted_sources"):
+            # If the user can use restricted sources, add them in.
             for source_iter in settings.SOURCES_RESTRICTED:
                 sources.append(source_iter)
 
+    # Get rid of "all", it's just a meta-source
     if "all" in sources:
         sources.remove("all")