diff options
| -rw-r--r-- | cmd2/argparse_custom.py | 88 | ||||
| -rw-r--r-- | tests/test_argparse_custom.py | 25 |
2 files changed, 85 insertions, 28 deletions
diff --git a/cmd2/argparse_custom.py b/cmd2/argparse_custom.py index 5432314b..2a7be287 100644 --- a/cmd2/argparse_custom.py +++ b/cmd2/argparse_custom.py @@ -94,6 +94,14 @@ Tab Completion: as dynamic. Therefore it is up to the developer to validate if the user has typed an acceptable value for these arguments. + The following functions exist in cases where you may want to manually add choice providing function/methods to + an existing argparse action. For instance, in __init__() of a custom action class. + + set_choices_function(action, func) + set_choices_method(action, method) + set_completer_function(action, func) + set_completer_method(action, method) + CompletionItem Class: This class was added to help in cases where uninformative data is being tab completed. For instance, tab completing ID numbers isn't very helpful to a user without context. Returning a list of CompletionItems @@ -223,6 +231,9 @@ class CompletionItem(str): self.description = desc +############################################################################################################ +# Class and functions related to ChoicesCallable +############################################################################################################ class ChoicesCallable: """ Enables using a callable as the choices provider for an argparse argument. @@ -241,6 +252,48 @@ class ChoicesCallable: self.to_call = to_call +def _set_choices_callable(action: argparse.Action, choices_callable: ChoicesCallable) -> None: + """ + Set the choices_callable attribute of an argparse Action + :param action: action being edited + :param choices_callable: the ChoicesCallable instance to use + :raises: TypeError if used on incompatible action type + """ + # Verify consistent use of parameters + if action.choices is not None: + err_msg = ("None of the following parameters can be used alongside a choices parameter:\n" + "choices_function, choices_method, completer_function, completer_method") + raise (TypeError(err_msg)) + elif action.nargs == 0: + err_msg = ("None of the following parameters can be used on an action that takes no arguments:\n" + "choices_function, choices_method, completer_function, completer_method") + raise (TypeError(err_msg)) + + setattr(action, ATTR_CHOICES_CALLABLE, choices_callable) + + +def set_choices_function(action: argparse.Action, choices_function: Callable[[], Iterable[Any]]) -> None: + """Set choices_function on an argparse action""" + _set_choices_callable(action, ChoicesCallable(is_method=False, is_completer=False, to_call=choices_function)) + + +def set_choices_method(action: argparse.Action, choices_method: Callable[[Any], Iterable[Any]]) -> None: + """Set choices_method on an argparse action""" + _set_choices_callable(action, ChoicesCallable(is_method=True, is_completer=False, to_call=choices_method)) + + +def set_completer_function(action: argparse.Action, + completer_function: Callable[[str, str, int, int], List[str]]) -> None: + """Set completer_function on an argparse action""" + _set_choices_callable(action, ChoicesCallable(is_method=False, is_completer=True, to_call=completer_function)) + + +def set_completer_method(action: argparse.Action, + completer_method: Callable[[Any, str, str, int, int], List[str]]) -> None: + """Set completer_method on an argparse action""" + _set_choices_callable(action, ChoicesCallable(is_method=True, is_completer=True, to_call=completer_method)) + + ############################################################################################################ # Patch _ActionsContainer.add_argument with our wrapper to support more arguments ############################################################################################################ @@ -291,7 +344,17 @@ def _add_argument_wrapper(self, *args, See the header of this file for more information :return: the created argument action + :raises ValueError on incorrect parameter usage """ + # Verify consistent use of arguments + choices_callables = [choices_function, choices_method, completer_function, completer_method] + num_params_set = len(choices_callables) - choices_callables.count(None) + + if num_params_set > 1: + err_msg = ("Only one of the following parameters may be used at a time:\n" + "choices_function, choices_method, completer_function, completer_method") + raise (ValueError(err_msg)) + # Pre-process special ranged nargs nargs_range = None @@ -345,34 +408,17 @@ def _add_argument_wrapper(self, *args, # Create the argument using the original add_argument function new_arg = orig_actions_container_add_argument(self, *args, **kwargs) - # Verify consistent use of arguments - choices_params = [new_arg.choices, choices_function, choices_method, completer_function, completer_method] - num_params_set = len(choices_params) - choices_params.count(None) - - if num_params_set > 1: - err_msg = ("Only one of the following parameters may be used at a time:\n" - "choices, choices_function, choices_method, completer_function, completer_method") - raise (ValueError(err_msg)) - elif num_params_set > 0 and new_arg.nargs == 0: - err_msg = ("None of the following parameters can be used for this type of action:\n" - "choices, choices_function, choices_method, completer_function, completer_method") - raise (TypeError(err_msg)) - # Set the custom attributes setattr(new_arg, ATTR_NARGS_RANGE, nargs_range) if choices_function: - setattr(new_arg, ATTR_CHOICES_CALLABLE, - ChoicesCallable(is_method=False, is_completer=False, to_call=choices_function)) + set_choices_function(new_arg, choices_function) elif choices_method: - setattr(new_arg, ATTR_CHOICES_CALLABLE, - ChoicesCallable(is_method=True, is_completer=False, to_call=choices_method)) + set_choices_method(new_arg, choices_method) elif completer_function: - setattr(new_arg, ATTR_CHOICES_CALLABLE, - ChoicesCallable(is_method=False, is_completer=True, to_call=completer_function)) + set_completer_function(new_arg, completer_function) elif completer_method: - setattr(new_arg, ATTR_CHOICES_CALLABLE, - ChoicesCallable(is_method=True, is_completer=True, to_call=completer_method)) + set_completer_method(new_arg, completer_method) setattr(new_arg, ATTR_SUPPRESS_TAB_HINT, suppress_tab_hint) setattr(new_arg, ATTR_DESCRIPTIVE_COMPLETION_HEADER, descriptive_header) diff --git a/tests/test_argparse_custom.py b/tests/test_argparse_custom.py index f5d45fd1..99afe2dd 100644 --- a/tests/test_argparse_custom.py +++ b/tests/test_argparse_custom.py @@ -40,17 +40,15 @@ def fake_func(): @pytest.mark.parametrize('kwargs, is_valid', [ - ({'choices': []}, True), ({'choices_function': fake_func}, True), ({'choices_method': fake_func}, True), ({'completer_function': fake_func}, True), ({'completer_method': fake_func}, True), - ({'choices': [], 'choices_function': fake_func}, False), - ({'choices': [], 'choices_method': fake_func}, False), + ({'choices_function': fake_func, 'choices_method': fake_func}, False), ({'choices_method': fake_func, 'completer_function': fake_func}, False), - ({'choices_method': fake_func, 'completer_method': fake_func}, False), + ({'completer_function': fake_func, 'completer_method': fake_func}, False), ]) -def test_apcustom_choices_params_count(kwargs, is_valid): +def test_apcustom_choices_callable_count(kwargs, is_valid): parser = Cmd2ArgumentParser(prog='test') try: parser.add_argument('name', **kwargs) @@ -66,11 +64,24 @@ def test_apcustom_choices_params_count(kwargs, is_valid): ({'completer_function': fake_func}), ({'completer_method': fake_func}) ]) -def test_apcustom_no_choices_when_nargs_is_0(kwargs): +def test_apcustom_no_choices_callables_alongside_choices(kwargs): + with pytest.raises(TypeError) as excinfo: + parser = Cmd2ArgumentParser(prog='test') + parser.add_argument('name', choices=['my', 'choices', 'list'], **kwargs) + assert 'None of the following parameters can be used alongside a choices parameter' in str(excinfo.value) + + +@pytest.mark.parametrize('kwargs', [ + ({'choices_function': fake_func}), + ({'choices_method': fake_func}), + ({'completer_function': fake_func}), + ({'completer_method': fake_func}) +]) +def test_apcustom_no_choices_callables_when_nargs_is_0(kwargs): with pytest.raises(TypeError) as excinfo: parser = Cmd2ArgumentParser(prog='test') parser.add_argument('name', action='store_true', **kwargs) - assert 'None of the following parameters can be used' in str(excinfo.value) + assert 'None of the following parameters can be used on an action that takes no arguments' in str(excinfo.value) def test_apcustom_usage(): |