replace default --help processor with one that includes the list of subcommands available

cliff/app.py

@@ -23,6 +23,7 @@ class App(object):
         self.parser = optparse.OptionParser(
             description=description,
             version='%prog {}'.format(version),
+            add_help_option=False,
             )
         self.parser.disable_interspersed_args()
         self.parser.add_option(
@@ -31,8 +32,27 @@ class App(object):
             dest='verbose',
             help='Increase verbosity of output. Can be repeated.',
             )
+        self.parser.add_option(
+            '-h', action='help',
+            help="show this help message and exit",
+            )
+        self.parser.add_option(
+            '--help', action='callback',
+            callback=self.show_verbose_help,
+            help="show verbose help message and exit",
+            )
         return
 
+    def show_verbose_help(self, *args):
+        self.parser.print_help()
+        print('')
+        print('Commands:')
+        for name, ep in sorted(self.command_manager):
+            factory = ep.load()
+            cmd = factory(self, None)
+            print('  %-13s  %s' % (name, cmd.get_description()))
+        raise SystemExit()
+
     def run(self, argv):
         parsed_args, remainder = self.parser.parse_args(argv)
         # FIXME(dhellmann): set up logging based on verbosity flag

cliff/commandmanager.py

@@ -24,6 +24,9 @@ class CommandManager(object):
             self.commands[ep.name.replace('_', ' ')] = ep
         return
 
+    def __iter__(self):
+        return iter(self.commands.items())
+
     def find_command(self, argv):
         """Given an argument list, find a command and
         return the processor and any remaining arguments.

demoapp/cliffdemo/simple.py

@@ -3,6 +3,7 @@ from cliff.command import Command
 
 
 class Simple(Command):
+    "A simple command that prints a message."
 
     def run(self, parsed_args):
         print 'hi!'