Merge with 7ce7ac4630e72a16cadded867950d3d91e03b31f

setup.py

@@ -14,13 +14,17 @@ setup(
     url='', #TODO: Bitbucket URL here
     install_requires=[
         'WebOb',
-        'WebError'
+        'WebError',
+        'ArgParse',
     ],
     packages=find_packages('src', exclude=['distribute_setup']),
     package_dir={'': 'src'},
     entry_points={
         'milla.request_validator': [
             'default = milla.auth:RequestValidator'
-        ]
+        ],
+        'console_scripts': [
+            'milla-cli = milla.cli:main'
+        ],
     }
 )

src/milla/cli.py

@@ -0,0 +1,109 @@
+# Copyright 2011 Dustin C. Hatch
+# 
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+# 
+#     http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+'''Module milla.cli
+
+Please give me a docstring!
+
+:Created: May 30, 2011
+:Author: dustin
+:Updated: $Date$
+:Updater: $Author$
+'''
+import argparse
+import pkg_resources
+import warnings
+
+class CommandWarning(UserWarning):
+    '''A warning raised when a command cannot be loaded or used'''
+    
+
+class CommandLineInterface(object):
+    '''Wrapper class for the Milla CLI'''
+    
+    PROGNAME = 'milla-cli'
+    EPGROUP = 'milla.command'
+
+    def __init__(self):
+        self.parser = argparse.ArgumentParser(prog=self.PROGNAME)
+        subparsers = None
+        subcmds = pkg_resources.iter_entry_points(self.EPGROUP)
+        for cmd in subcmds:
+            try:
+                Command = cmd.load()
+            except Exception as e:
+                warnings.warn("Unable to load command from entry point named "
+                              "'{epname}': {e}".format(
+                                  epname=cmd,
+                                  e=e,
+                              ), CommandWarning)
+                continue
+
+            if not hasattr(Command, 'name') or not Command.name:
+                warnings.warn("Command '{cmd}' from '{mod}' does not have a "
+                              "name and cannot be used".format(
+                                  cmd=Command.__name__,
+                                  mod=Command.__module__
+                              ), CommandWarning)
+                continue
+
+            if not subparsers:
+                subparsers = self.parser.add_subparsers()
+            subcmd = subparsers.add_parser(Command.name, *Command.parser_args,
+                                           **Command.parser_kwargs)
+            Command.setup_args(subcmd)
+            subcmd.set_defaults(func=Command())
+
+
+class Command(object):
+    '''Base class for "commands"
+    
+    To create a command, subclass this class and override the following
+    attributes:
+    
+    * ``name`` -- Name of the subcommand
+    * ``parser_args`` -- arguments to pass to ``add_parser`` when
+      creating the ArgumentParser for the command
+    * ``parser_kwargs`` -- keywords to pass to ``add_parser``
+    * ``setup_args()`` -- Class method called to add arguments, etc. to
+      the command subparser.
+    '''
+
+    #: Tuple of arguments to pass to the ArgumentParser constructor
+    parser_args = ()
+    #: Dict of keywords to pass to the ArgumentParser constructor
+    parser_kwargs = {}
+    
+    @classmethod
+    def setup_args(cls, parser):
+        '''Add arguments, etc to the command subparser
+        
+        Override this method to add arguments, options, etc. to the
+        subparser for the command. The default implementation does
+        not add anything.
+        
+        :param parser: An instance of ``ArgumentParser`` for the
+           ``milla-cli`` subcommand
+        '''
+        
+        pass
+
+def main():
+    '''Entry point for the ``milla-cli`` console script'''
+    
+    cli = CommandLineInterface()
+    args = cli.parser.parse_args()
+    func = args.func
+    del args.func
+    func.args = args
+    func()