Merge lp:~jelmer/bzr/config-registry-option into lp:bzr

[Jelmer Vernooij]

Add bzrlib.config.RegistryOption.

Add bzrlib.config.RegistryOption - an Option subclass which can be set to a registry key, and provides an according help.

[Vincent Ladeuil (vila)]

Perfectly the spirit for code and tests :)

Just add a line in doc/developers/configuration.txt mentioning the RegistryOption and we're all set (this doc may need more detailed explanations but no urgency ;).

review: Needs Fixing

=== modified file 'bzrlib/config.py'
--- bzrlib/config.py	2012-01-20 13:21:01 +0000
+++ bzrlib/config.py	2012-01-28 15:40:30 +0000
@@ -2396,13 +2396,17 @@
             raise AssertionError('%r is not supported as a default value'
                                  % (default,))
         self.default_from_env = default_from_env
-        self.help = help
+        self._help = help
         self.from_unicode = from_unicode
         self.unquote = unquote
         if invalid and invalid not in ('warning', 'error'):
             raise AssertionError("%s not supported for 'invalid'" % (invalid,))
         self.invalid = invalid
 
+    @property
+    def help(self):
+        return self._help
+
     def convert_from_unicode(self, store, unicode_value):
         if self.unquote and store is not None and unicode_value is not None:
             unicode_value = store.unquote(unicode_value)
@@ -2548,6 +2552,42 @@
         return l
 
 
+class RegistryOption(Option):
+    """Option for a choice from a registry."""
+
+    def __init__(self, name, registry, default_from_env=None,
+                 help=None, invalid=None):
+        """A registry based Option definition.
+
+        This overrides the base class so the conversion from a unicode string
+        can take quoting into account.
+        """
+        super(RegistryOption, self).__init__(
+            name, default=lambda: unicode(registry.default_key),
+            default_from_env=default_from_env,
+            from_unicode=self.from_unicode, help=help,
+            invalid=invalid, unquote=False)
+        self.registry = registry
+
+    def from_unicode(self, unicode_str):
+        if not isinstance(unicode_str, basestring):
+            raise TypeError
+        try:
+            return self.registry.get(unicode_str)
+        except KeyError:
+            raise ValueError(
+                "Invalid value %s for %s."
+                "See help for a list of possible values." % (unicode_str,
+                    self.name))
+
+    @property
+    def help(self):
+        ret = [self._help, "\n\nThe following values are supported:\n"]
+        for key in self.registry.keys():
+            ret.append(" %s - %s\n" % (key, self.registry.get_help(key)))
+        return "".join(ret)
+
+
 class OptionRegistry(registry.Registry):
     """Register config options by their name.
 
 
=== modified file 'bzrlib/tests/test_config.py'
--- bzrlib/tests/test_config.py	2012-01-09 12:20:41 +0000
+++ bzrlib/tests/test_config.py	2012-01-28 15:40:30 +0000
@@ -35,6 +35,7 @@
     mail_client,
     ui,
     urlutils,
+    registry as _mod_registry,
     remote,
     tests,
     trace,
@@ -2480,6 +2481,54 @@
         self.assertConverted([u'bar'], opt, u'bar')
 
 
+class TestRegistryOption(tests.TestCase, TestOptionConverterMixin):
+
+    def get_option(self, registry):
+        return config.RegistryOption('foo', registry,
+                help='A registry option.')
+
+    def test_convert_invalid(self):
+        registry = _mod_registry.Registry()
+        opt = self.get_option(registry)
+        self.assertConvertInvalid(opt, [1])
+        self.assertConvertInvalid(opt, u"notregistered")
+
+    def test_convert_valid(self):
+        registry = _mod_registry.Registry()
+        registry.register("someval", 1234)
+        opt = self.get_option(registry)
+        # Using a bare str() just in case
+        self.assertConverted(1234, opt, "someval")
+        self.assertConverted(1234, opt, u'someval')
+        self.assertConverted(None, opt, None)
+
+    def test_help(self):
+        registry = _mod_registry.Registry()
+        registry.register("someval", 1234, help="some option")
+        registry.register("dunno", 1234, help="some other option")
+        opt = self.get_option(registry)
+        self.assertEquals(
+            'A registry option.\n'
+            '\n'
+            'The following values are supported:\n'
+            ' dunno - some other option\n'
+            ' someval - some option\n',
+            opt.help)
+
+    def test_get_help_text(self):
+        registry = _mod_registry.Registry()
+        registry.register("someval", 1234, help="some option")
+        registry.register("dunno", 1234, help="some other option")
+        opt = self.get_option(registry)
+        self.assertEquals(
+            'A registry option.\n'
+            '\n'
+            'The following values are supported:\n'
+            ' dunno - some other option\n'
+            ' someval - some option\n',
+            opt.get_help_text())
+
+
 class TestOptionRegistry(tests.TestCase):
 
     def setUp(self):
 
=== modified file 'doc/developers/configuration.txt'
--- doc/developers/configuration.txt	2012-01-09 12:20:41 +0000
+++ doc/developers/configuration.txt	2012-01-28 15:40:30 +0000
@@ -213,6 +213,10 @@
 
 If you need a list value, you should use ``ListOption`` instead.
 
+For options that take their values from a ``Registry`` object,
+``RegistryOption`` can be used. This will automatically take care of
+looking up the specified values in the dictionary and documenting the
+possible values in help.
 
 Sections
 --------
 
=== modified file 'doc/en/release-notes/bzr-2.6.txt'
--- doc/en/release-notes/bzr-2.6.txt	2012-01-24 16:10:08 +0000
+++ doc/en/release-notes/bzr-2.6.txt	2012-01-28 15:40:30 +0000
@@ -52,6 +52,9 @@
   or tuples of bytestrings.
   (Jelmer Vernooij)
 
+* New configuration option class ``RegistryOption`` which is backed
+  onto a registry. (Jelmer Vernooij)
+
 Internals
 *********