Made CompletionError exception available to non-argparse tab completion

Author: kmvanbrunt

CHANGELOG.md

@@ -13,6 +13,7 @@
         * `__name__`: __main__
         * `__file__`: script path (as typed, ~ will be expanded)
     * Only tab complete after redirection tokens if redirection is allowed
+    * Made `CompletionError` exception available to non-argparse tab completion
 * Other
     * Removed undocumented `py run` command since it was replaced by `run_pyscript` a while ago
     * Renamed `AutoCompleter` to `ArgparseCompleter` for clarity

cmd2/__init__.py

@@ -11,7 +11,7 @@
     pass
 
 from .ansi import style, fg, bg
-from .argparse_custom import Cmd2ArgumentParser, CompletionError, CompletionItem, set_default_argument_parser
+from .argparse_custom import Cmd2ArgumentParser, CompletionItem, set_default_argument_parser
 
 # Check if user has defined a module that sets a custom value for argparse_custom.DEFAULT_ARGUMENT_PARSER
 import argparse
@@ -27,4 +27,4 @@
 from .decorators import categorize, with_argument_list, with_argparser, with_argparser_and_unknown_args, with_category
 from .parsing import Statement
 from .py_bridge import CommandResult
-from .utils import Settable
+from .utils import CompletionError, Settable

cmd2/argparse_completer.py

@@ -117,13 +117,6 @@ def my_completer_method(self, text, line, begidx, endidx, arg_tokens)
     their values. All tokens are stored in the dictionary as the raw strings provided on the command line. It is up to
     the developer to determine if the user entered the correct argument type (e.g. int) and validate their values.
 
-CompletionError Class:
-    Raised during tab completion operations to report any sort of error you want printed by the ArgparseCompleter
-
-    Example use cases
-    - Reading a database to retrieve a tab completion data set failed
-    - A previous command line argument that determines the data set being completed is invalid
-
 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
@@ -229,17 +222,6 @@ def generate_range_error(range_min: int, range_max: Union[int, float]) -> str:
     return err_str
 
 
-class CompletionError(Exception):
-    """
-    Raised during tab completion operations to report any sort of error you want printed by the ArgparseCompleter
-
-    Example use cases
-    - Reading a database to retrieve a tab completion data set failed
-    - A previous command line argument that determines the data set being completed is invalid
-    """
-    pass
-
-
 class CompletionItem(str):
     """
     Completion item with descriptive text attached

cmd2/argparse_custom.py

@@ -47,13 +47,13 @@
 from . import constants
 from . import plugin
 from . import utils
-from .argparse_custom import CompletionError, CompletionItem, DEFAULT_ARGUMENT_PARSER
+from .argparse_custom import CompletionItem, DEFAULT_ARGUMENT_PARSER
 from .clipboard import can_clip, get_paste_buffer, write_to_paste_buffer
 from .decorators import with_argparser
 from .history import History, HistoryItem
 from .parsing import StatementParser, Statement, Macro, MacroArg, shlex_split
 from .rl_utils import rl_type, RlType, rl_get_point, rl_set_prompt, vt100_support, rl_make_safe_prompt, rl_warning
-from .utils import Settable
+from .utils import CompletionError, Settable
 
 # Set up readline
 if rl_type == RlType.NONE:  # pragma: no cover
@@ -1416,6 +1416,12 @@ def complete(self, text: str, state: int) -> Optional[str]:
             except IndexError:
                 return None
 
+        except CompletionError as e:
+            err_str = str(e)
+            if err_str:
+                ansi.style_aware_write(sys.stdout, err_str + '\n')
+                rl_force_redisplay()
+            return None
         except Exception as e:
             # Insert a newline so the exception doesn't print in the middle of the command line being tab completed
             self.perror()

cmd2/cmd2.py

@@ -72,6 +72,17 @@ def str_to_bool(val: str) -> bool:
     raise ValueError("must be True or False (case-insensitive)")
 
 
+class CompletionError(Exception):
+    """
+    Raised during tab completion operations to report any sort of error you want printed by the ArgparseCompleter
+
+    Example use cases
+    - Reading a database to retrieve a tab completion data set failed
+    - A previous command line argument that determines the data set being completed is invalid
+    """
+    pass
+
+
 class Settable:
     """Used to configure a cmd2 instance member to be settable via the set command in the CLI"""
     def __init__(self, name: str, val_type: Callable, description: str, *,

cmd2/utils.py

@@ -6,8 +6,8 @@
 import argparse
 from typing import Dict, List
 
-from cmd2 import Cmd, Cmd2ArgumentParser, with_argparser, CompletionError, CompletionItem
-from cmd2.utils import basic_complete
+from cmd2 import Cmd, Cmd2ArgumentParser, with_argparser, CompletionItem
+from cmd2.utils import basic_complete, CompletionError
 
 # Data source for argparse.choices
 food_item_strs = ['Pizza', 'Ham', 'Ham Sandwich', 'Potato']

examples/argparse_completion.py

@@ -9,8 +9,8 @@
 import pytest
 
 import cmd2
-from cmd2 import with_argparser, Cmd2ArgumentParser, CompletionError, CompletionItem
-from cmd2.utils import StdSim, basic_complete
+from cmd2 import with_argparser, Cmd2ArgumentParser, CompletionItem
+from cmd2.utils import CompletionError, StdSim, basic_complete
 from .conftest import run_cmd, complete_tester
 
 # Lists used in our tests (there is a mix of sorted and unsorted on purpose)