Add --only and --except command-line arguments

Internal to Dotbot, we use the name "skip" instead of "except", because
the latter is a keyword, and using a name like "except_" didn't seem as
nice.

2 files changed, 12 insertions, 2 deletions

diff --git a/dotbot/cli.py b/dotbot/cli.py
index 77bd439..258ea87 100644
--- a/dotbot/cli.py
+++ b/dotbot/cli.py
@@ -28,6 +28,10 @@ def add_options(parser):
         action='store_true', help='disable built-in plugins')
     parser.add_argument('--plugin-dir', action='append', dest='plugin_dirs', default=[],
         metavar='PLUGIN_DIR', help='load all plugins in PLUGIN_DIR')
+    parser.add_argument('--only', nargs='+',
+            help='only run specified directives', metavar='DIRECTIVE')
+    parser.add_argument('--except', nargs='+', dest='skip',
+            help='skip specified directives', metavar='DIRECTIVE')
     parser.add_argument('--no-color', dest='no_color', action='store_true',
         help='disable color output')
     parser.add_argument('--version', action='store_true',
@@ -78,7 +82,7 @@ def main():
             # default to directory of config file
             base_directory = os.path.dirname(os.path.abspath(options.config_file))
         os.chdir(base_directory)
-        dispatcher = Dispatcher(base_directory)
+        dispatcher = Dispatcher(base_directory, only=options.only, skip=options.skip)
         success = dispatcher.dispatch(tasks)
         if success:
             log.info('\n==> All tasks executed successfully')
diff --git a/dotbot/dispatcher.py b/dotbot/dispatcher.py
index 36eac02..10e4293 100644
--- a/dotbot/dispatcher.py
+++ b/dotbot/dispatcher.py
@@ -4,10 +4,12 @@ from .messenger import Messenger
 from .context import Context
 
 class Dispatcher(object):
-    def __init__(self, base_directory):
+    def __init__(self, base_directory, only=None, skip=None):
         self._log = Messenger()
         self._setup_context(base_directory)
         self._load_plugins()
+        self._only = only
+        self._skip = skip
 
     def _setup_context(self, base_directory):
         path = os.path.abspath(
@@ -20,6 +22,10 @@ class Dispatcher(object):
         success = True
         for task in tasks:
             for action in task:
+                if self._only is not None and action not in self._only \
+                        or self._skip is not None and action in self._skip:
+                    self._log.info('Skipping action %s' % action)
+                    continue
                 handled = False
                 if action == 'defaults':
                     self._context.set_defaults(task[action]) # replace, not update