Added a check to verify the existence of a descriptive header. Added a constant. Updated example to use the constant.

3 files changed, 11 insertions, 7 deletions

diff --git a/cmd2/argparse_completer.py b/cmd2/argparse_completer.py
index 1bc7f342..995aeb48 100755
--- a/cmd2/argparse_completer.py
+++ b/cmd2/argparse_completer.py
@@ -77,6 +77,7 @@ from .rl_utils import rl_force_redisplay
 # define the completion choices for the argument. You may provide a Collection or a Function.
 ACTION_ARG_CHOICES = 'arg_choices'
 ACTION_SUPPRESS_HINT = 'suppress_hint'
+ACTION_DESCRIPTIVE_COMPLETION_HEADER = 'desc_header'
 
 
 class CompletionItem(str):
@@ -456,7 +457,11 @@ class AutoCompleter(object):
                                                                      fill_width=fill_width)
                 completions_with_desc.append(entry)
 
-            header = '\n{: <{token_width}}{}'.format(action.dest.upper(), action.desc_header, token_width=token_width+2)
+            try:
+                desc_header = action.desc_header
+            except AttributeError:
+                desc_header = 'Description'
+            header = '\n{: <{token_width}}{}'.format(action.dest.upper(), desc_header, token_width=token_width+2)
 
             self._cmd2_app.completion_header = header
             self._cmd2_app.display_matches = completions_with_desc
diff --git a/cmd2/cmd2.py b/cmd2/cmd2.py
index 3d2a8afe..75946764 100644
--- a/cmd2/cmd2.py
+++ b/cmd2/cmd2.py
@@ -50,7 +50,7 @@ from cmd2.parsing import StatementParser, Statement
 
 # Set up readline
 from .rl_utils import rl_type, RlType
-if rl_type == RlType.NONE:
+if rl_type == RlType.NONE: # pragma: no cover
     rl_warning = "Readline features including tab completion have been disabled since no \n" \
                  "supported version of readline was found. To resolve this, install \n" \
                  "pyreadline on Windows or gnureadline on Mac.\n\n"
@@ -84,7 +84,7 @@ from .argparse_completer import AutoCompleter, ACArgumentParser
 # Newer versions of pyperclip are released as a single file, but older versions had a more complicated structure
 try:
     from pyperclip.exceptions import PyperclipException
-except ImportError:
+except ImportError: # pragma: no cover
     # noinspection PyUnresolvedReferences
     from pyperclip import PyperclipException
 
@@ -121,7 +121,7 @@ ipython_available = True
 try:
     # noinspection PyUnresolvedReferences,PyPackageRequirements
     from IPython import embed
-except ImportError:
+except ImportError: # pragma: no cover
     ipython_available = False
 
 __version__ = '0.9.2a'
diff --git a/examples/tab_autocompletion.py b/examples/tab_autocompletion.py
index 817ceb72..342cfff5 100755
--- a/examples/tab_autocompletion.py
+++ b/examples/tab_autocompletion.py
@@ -116,9 +116,6 @@ class TabCompleteExample(cmd2.Cmd):
         for movie_id, movie_entry in self.MOVIE_DATABASE.items():
             completions_with_desc.append(argparse_completer.CompletionItem(movie_id, movie_entry['title']))
 
-        setattr(self.vid_delete_movie_id, 'desc_header', 'Title')
-        setattr(self.movies_delete_movie_id, 'desc_header', 'Title')
-
         return completions_with_desc
 
     # This demonstrates a number of customizations of the AutoCompleter version of ArgumentParser
@@ -267,6 +264,7 @@ class TabCompleteExample(cmd2.Cmd):
     vid_movies_delete_parser = vid_movies_commands_subparsers.add_parser('delete')
     vid_delete_movie_id = vid_movies_delete_parser.add_argument('movie_id', help='Movie ID')
     setattr(vid_delete_movie_id, argparse_completer.ACTION_ARG_CHOICES, instance_query_movie_ids)
+    setattr(vid_delete_movie_id, argparse_completer.ACTION_DESCRIPTIVE_COMPLETION_HEADER, 'Title')
 
     vid_shows_parser = video_types_subparsers.add_parser('shows')
     vid_shows_parser.set_defaults(func=_do_vid_media_shows)
@@ -344,6 +342,7 @@ class TabCompleteExample(cmd2.Cmd):
     movies_delete_parser = movies_commands_subparsers.add_parser('delete')
     movies_delete_movie_id = movies_delete_parser.add_argument('movie_id', help='Movie ID')
     setattr(movies_delete_movie_id, argparse_completer.ACTION_ARG_CHOICES, 'instance_query_movie_ids')
+    setattr(movies_delete_movie_id, argparse_completer.ACTION_DESCRIPTIVE_COMPLETION_HEADER, 'Title')
 
     movies_load_parser = movies_commands_subparsers.add_parser('load')
     movie_file_action = movies_load_parser.add_argument('movie_file', help='Movie database')