Added support for argparse sub-commands when using cmd2 decorators

Modified the do_help() method to behave differently for methods which have been decorated with an argparse ArgumentParser.
This is so that help will properly deal with sub-command help.

Suppose you have a base command "base" which has two sub-commands, "foo" and "bar".  Then "help base" will provide very different help text than "help base foo".

Slightly tweaked the two argparse decorators to set an attribute in the decorated function's dictionary so that the do_help method can know which functions have an ArgumentParser and which do not.

Added a "subcommands.py" example for demonstrating how to create and use subcommands based on argparse and the cmd2 @with_argument_parser decorator.

1 files changed, 20 insertions, 2 deletions

diff --git a/cmd2.py b/cmd2.py
index 378ac097..204e6450 100755
--- a/cmd2.py
+++ b/cmd2.py
@@ -292,7 +292,12 @@ def with_argparser_and_unknown_args(argparser):
             argparser.description = func.__doc__
 
         cmd_wrapper.__doc__ = argparser.format_help()
+
+        # Mark this function as having an argparse ArgumentParser (used by do_help)
+        cmd_wrapper.__dict__['has_parser'] = True
+
         return cmd_wrapper
+
     return arg_decorator
 
 
@@ -316,7 +321,12 @@ def with_argument_parser(argparser):
             argparser.description = func.__doc__
 
         cmd_wrapper.__doc__ = argparser.format_help()
+
+        # Mark this function as having an argparse ArgumentParser (used by do_help)
+        cmd_wrapper.__dict__['has_parser'] = True
+
         return cmd_wrapper
+
     return arg_decorator
 
 
@@ -1198,8 +1208,16 @@ class Cmd(cmd.Cmd):
             # Getting help for a specific command
             funcname = self._func_named(arglist[0])
             if funcname:
-                # No special behavior needed, delegate to cmd base class do_help()
-                cmd.Cmd.do_help(self, funcname[3:])
+                # Check to see if this function was decorated with an argparse ArgumentParser
+                func = getattr(self, funcname)
+                if func.__dict__.get('has_parser', False):
+                    # Function has an argparser, so get help based on all the arguments in case there are sub-commands
+                    new_arglist = arglist[1:]
+                    new_arglist.append('-h')
+                    func(new_arglist)
+                else:
+                    # No special behavior needed, delegate to cmd base class do_help()
+                    cmd.Cmd.do_help(self, funcname[3:])
         else:
             # Show a menu of what commands help can be gotten for
             self._help_menu()