diff options
| -rw-r--r-- | libbe/command/__init__.py | 3 | ||||
| -rw-r--r-- | libbe/command/base.py | 33 | ||||
| -rw-r--r-- | libbe/ui/command_line.py | 26 |
3 files changed, 49 insertions, 13 deletions
diff --git a/libbe/command/__init__.py b/libbe/command/__init__.py index 1cad096..832218c 100644 --- a/libbe/command/__init__.py +++ b/libbe/command/__init__.py @@ -19,6 +19,7 @@ import base UserError = base.UserError +UsageError = base.UsageError UnknownCommand = base.UnknownCommand get_command = base.get_command get_command_class = base.get_command_class @@ -33,7 +34,7 @@ UnconnectedStorageGetter = base.UnconnectedStorageGetter StorageCallbacks = base.StorageCallbacks UserInterface = base.UserInterface -__all__ = [UserError, UnknownCommand, +__all__ = [UserError, UsageError, UnknownCommand, get_command, get_command_class, commands, Option, Argument, Command, InputOutput, StdInputOutput, StringInputOutput, diff --git a/libbe/command/base.py b/libbe/command/base.py index b5f5a22..48bb7ab 100644 --- a/libbe/command/base.py +++ b/libbe/command/base.py @@ -27,13 +27,36 @@ import libbe.ui.util.user import libbe.util.encoding import libbe.util.plugin -class UserError(Exception): + +class UserError (Exception): + "An error due to improper BE usage." pass -class UnknownCommand(UserError): - def __init__(self, cmd): - Exception.__init__(self, "Unknown command '%s'" % cmd) - self.cmd = cmd + +class UsageError (UserError): + """A serious parsing error due to invalid BE command construction. + + The distinction between `UserError`\s and the more specific + `UsageError`\s is that when displaying a `UsageError` to the user, + the user is pointed towards the command usage information. Use + the more general `UserError` if you feel that usage information + would not be particularly enlightening. + """ + def __init__(self, command=None, command_name=None, message=None): + super(UsageError, self).__init__(message) + self.command = command + if command_name is None and command is not None: + command_name = command.name + self.command_name = command_name + self.message = message + + +class UnknownCommand (UsageError): + def __init__(self, command_name): + super(UnknownCommand, self).__init__( + command_name=command_name, + message="Unknown command '%s'" % command_name) + def get_command(command_name): """Retrieves the module for a user command diff --git a/libbe/ui/command_line.py b/libbe/ui/command_line.py index 52daa4b..3f70962 100644 --- a/libbe/ui/command_line.py +++ b/libbe/ui/command_line.py @@ -137,8 +137,9 @@ class CmdOptionParser(optparse.OptionParser): raise libbe.command.UserError('Too many arguments') for arg in self.command.args[len(parsed_args):]: if arg.optional == False: - raise libbe.command.UserError( - 'Missing required argument %s' % arg.metavar) + raise libbe.command.UsageError( + command=self.command, + message='Missing required argument %s' % arg.metavar) return (options, parsed_args) def callback(self, option, opt, value, parser): @@ -289,6 +290,13 @@ def dispatch(ui, command, args): 'See http://docs.python.org/library/locale.html for details', ]) return 1 + except libbe.command.UsageError, e: + print >> ui.io.stdout, 'Usage Error:\n', e + if e.command: + print >> ui.io.stdout, e.command.usage() + print >> ui.io.stdout, 'For usage information, try' + print >> ui.io.stdout, ' be help %s' % e.command_name + return 1 except libbe.command.UserError, e: print >> ui.io.stdout, 'ERROR:\n', e return 1 @@ -314,15 +322,19 @@ def main(): options,args = parser.parse_args() except CallbackExit: return 0 - except libbe.command.UserError, e: - if str(e).endswith('COMMAND'): + except libbe.command.UsageError, e: + if isinstance(e.command, BE): # no command given, print usage string - print >> ui.io.stdout, 'ERROR:' - print >> ui.io.stdout, be.usage(), '\n', e + print >> ui.io.stdout, 'Usage Error:\n', e + print >> ui.io.stdout, be.usage() print >> ui.io.stdout, 'For example, try' print >> ui.io.stdout, ' be help' else: - print >> ui.io.stdout, 'ERROR:\n', e + print >> ui.io.stdout, 'Usage Error:\n', e + if e.command: + print >> ui.io.stdout, e.command.usage() + print >> ui.io.stdout, 'For usage information, try' + print >> ui.io.stdout, ' be help %s' % e.command_name return 1 command_name = args.pop(0) |