Added support for using cmd2 application class methods as an argument completion provider. The default completion implementation in Cmd2 automatically passes self to AutoCompleter to be passed to the class method.

Author: anselor

cmd2/argparse_completer.py

@@ -190,7 +190,8 @@ def __init__(self,
                  token_start_index: int = 1,
                  arg_choices: Dict[str, Union[List, Tuple, Callable]] = None,
                  subcmd_args_lookup: dict = None,
-                 tab_for_arg_help: bool = True):
+                 tab_for_arg_help: bool = True,
+                 cmd2_app=None):
         """
         Create an AutoCompleter
 
@@ -209,6 +210,7 @@ def __init__(self,
         self._arg_choices = arg_choices.copy() if arg_choices is not None else {}
         self._token_start_index = token_start_index
         self._tab_for_arg_help = tab_for_arg_help
+        self._cmd2_app = cmd2_app
 
         self._flags = []  # all flags in this command
         self._flags_without_args = []  # all flags that don't take arguments
@@ -252,7 +254,8 @@ def __init__(self,
                         subcmd_start = token_start_index + len(self._positional_actions)
                         sub_completers[subcmd] = AutoCompleter(action.choices[subcmd], subcmd_start,
                                                                arg_choices=subcmd_args,
-                                                               subcmd_args_lookup=subcmd_lookup)
+                                                               subcmd_args_lookup=subcmd_lookup,
+                                                               cmd2_app=cmd2_app)
                         sub_commands.append(subcmd)
                     self._positional_completers[action.dest] = sub_completers
                     self._arg_choices[action.dest] = sub_commands
@@ -492,7 +495,16 @@ def _resolve_choices_for_arg(self, action: argparse.Action, used_values=()) -> L
             args = self._arg_choices[action.dest]
 
             if callable(args):
-                args = args()
+                try:
+                    if self._cmd2_app is not None:
+                        try:
+                            args = args(self._cmd2_app)
+                        except TypeError:
+                            args = args()
+                    else:
+                        args = args()
+                except TypeError:
+                    return []
 
             try:
                 iter(args)

cmd2/cmd2.py

@@ -1838,7 +1838,7 @@ def complete(self, text, state):
     def _autocomplete_default(self, text: str, line: str, begidx: int, endidx: int,
                               argparser: argparse.ArgumentParser) -> List[str]:
         """Default completion function for argparse commands."""
-        completer = AutoCompleter(argparser)
+        completer = AutoCompleter(argparser, cmd2_app=self)
 
         tokens, _ = self.tokens_for_completion(line, begidx, endidx)
         results = completer.complete_command(tokens, text, line, begidx, endidx)

examples/tab_autocompletion.py

@@ -95,6 +95,10 @@ def __init__(self):
                                  },
                      }
 
+    def instance_query_actors(self) -> List[str]:
+        """Simulating a function that queries and returns a completion values"""
+        return actors
+
     # This demonstrates a number of customizations of the AutoCompleter version of ArgumentParser
     #  - The help output will separately group required vs optional flags
     #  - The help output for arguments with multiple flags or with append=True is more concise
@@ -222,7 +226,7 @@ def _do_vid_media_shows(self, args) -> None:
 
     # tag the action objects with completion providers. This can be a collection or a callable
     setattr(director_action, argparse_completer.ACTION_ARG_CHOICES, static_list_directors)
-    setattr(actor_action, argparse_completer.ACTION_ARG_CHOICES, query_actors)
+    setattr(actor_action, argparse_completer.ACTION_ARG_CHOICES, instance_query_actors)
 
     vid_movies_delete_parser = vid_movies_commands_subparsers.add_parser('delete')