edit plugin: make temporary file reflect --set CLI arguments

beetsplug/edit.py

@@ -23,7 +23,7 @@
 
 import yaml
 
-from beets import plugins, ui, util
+from beets import plugins, ui, util, config
 from beets.dbcore import types
 from beets.importer import action
 from beets.ui.commands import PromptChoice, _do_query
@@ -155,9 +155,14 @@ def __init__(self):
             }
         )
 
+        self.readonly_fields = {}
+
         self.register_listener(
             "before_choose_candidate", self.before_choose_candidate_listener
         )
+        self.register_listener(
+            "import_begin", self.import_begin_listener
+        )
 
     def commands(self):
         edit_command = ui.Subcommand("edit", help="interactively edit metadata")
@@ -236,11 +241,22 @@ def edit_objects(self, objs, fields):
         # Get the content to edit as raw data structures.
         old_data = [flatten(o, fields) for o in objs]
 
+        # take set fields into account
+        if self.readonly_fields:
+            old_str = "# note: the following fields will be reset to their current values:\n"
+            for key in self.readonly_fields:
+                old_str += f"# - {key}\n"
+            for obj in old_data:
+                # those values will be enforced later anyway
+                obj.update(self.readonly_fields)
+        else:
+            old_str = ""
+
         # Set up a temporary file with the initial data for editing.
         new = NamedTemporaryFile(
             mode="w", suffix=".yaml", delete=False, encoding="utf-8"
         )
-        old_str = dump(old_data)
+        old_str += dump(old_data)
         new.write(old_str)
         new.close()
 
@@ -358,6 +374,12 @@ def before_choose_candidate_listener(self, session, task):
 
         return choices
 
+    def import_begin_listener(self, session):
+        """Load data from import session into self"""
+        self.readonly_fields = {}
+        for field, view in config["import"]["set_fields"].items():
+            self.readonly_fields[field] = view.get()
+
     def importer_edit(self, session, task):
         """Callback for invoking the functionality during an interactive
         import session on the *original* item tags.