provide an internal API for applications to register commands without going through setuptools (used for help handler)

1 files changed, 16 insertions, 1 deletions

diff --git a/cliff/commandmanager.py b/cliff/commandmanager.py
index 65af9ed..bb8bfe2 100644
--- a/cliff/commandmanager.py
+++ b/cliff/commandmanager.py
@@ -9,6 +9,18 @@ import pkg_resources
 LOG = logging.getLogger(__name__)
 
 
+class EntryPointWrapper(object):
+    """Wrap up a command class already imported to make it look like a plugin.
+    """
+
+    def __init__(self, name, command_class):
+        self.name = name
+        self.command_class = command_class
+
+    def load(self):
+        return self.command_class
+
+
 class CommandManager(object):
     """Discovers commands and handles lookup based on argv data.
     """
@@ -26,6 +38,9 @@ class CommandManager(object):
     def __iter__(self):
         return iter(self.commands.items())
 
+    def add_command(self, name, command_class):
+        self.commands[name] = EntryPointWrapper(name, command_class)
+
     def find_command(self, argv):
         """Given an argument list, find a command and
         return the processor and any remaining arguments.
@@ -42,5 +57,5 @@ class CommandManager(object):
                 cmd_factory = cmd_ep.load()
                 return (cmd_factory, name, search_args)
         else:
-            raise ValueError('Did not find command processor for %r' %
+            raise ValueError('Unknown command %r' %
                              (argv,))