Change parameters to use only default_from for dynamic default values.

Replace all occurences of create_default with equivalent default_from
and remove create_default from the framework. This is needed for
proper parameter validation, as there is no way to tell which
parameters to validate prior to calling create_default, because
create_default does not provide information about which parameters are
used for generating the default value.

ipalib/parameters.py

@@ -198,6 +198,8 @@ class DefaultFrom(ReadOnly):
         self.callback = callback
         if len(keys) == 0:
             fc = callback.func_code
+            if fc.co_flags & 0x0c:
+                raise ValueError("callback: variable-length argument list not allowed")
             self.keys = fc.co_varnames[:fc.co_argcount]
         else:
             self.keys = keys
@@ -308,13 +310,9 @@ class Param(ReadOnly):
         encoder
       - default_from: a custom function for generating default values of
         parameter instance
-      - create_default: a custom function for generating default values of
-        parameter instance. Unlike default_from attribute, this function
-        is not wrapped. `Param.get_default()` documentation provides further
-        details
       - autofill: by default, only `required` parameters get a default value
-        from default_from or create_default functions. When autofill is
-        enabled, optional attributes get the default value filled too
+        from the default_from function. When autofill is enabled, optional
+        attributes get the default value filled too
       - query: this attribute is controlled by framework. When the `query`
         is enabled, framework assumes that the value is only queried and not
         inserted in the LDAP. Validation is then relaxed - custom
@@ -379,7 +377,6 @@ class Param(ReadOnly):
         ('normalizer', callable, None),
         ('encoder', callable, None),
         ('default_from', DefaultFrom, None),
-        ('create_default', callable, None),
         ('autofill', bool, False),
         ('query', bool, False),
         ('attribute', bool, False),
@@ -481,20 +478,6 @@ class Param(ReadOnly):
                 class_rules.append(getattr(self, rule_name))
         check_name(self.cli_name)
 
-        # Check that only default_from or create_default was provided:
-        assert not hasattr(self, '_get_default'), self.nice
-        if callable(self.default_from):
-            if callable(self.create_default):
-                raise ValueError(
-                    '%s: cannot have both %r and %r' % (
-                        self.nice, 'default_from', 'create_default')
-                )
-            self._get_default = self.default_from
-        elif callable(self.create_default):
-            self._get_default = self.create_default
-        else:
-            self._get_default = None
-
         # Check that only 'include' or 'exclude' was provided:
         if None not in (self.include, self.exclude):
             raise ValueError(
@@ -990,59 +973,9 @@ class Param(ReadOnly):
         >>> kw = dict(first=u'John', department=u'Engineering')
         >>> login.get_default(**kw)
         u'my-static-login-default'
-
-        The second, less common way to construct a dynamic default is to provide
-        a callback via the ``create_default`` keyword argument.  Unlike a
-        ``default_from`` callback, your ``create_default`` callback will not get
-        wrapped in any dispatcher.  Instead, it will be called directly, which
-        means your callback must accept arbitrary keyword arguments, although
-        whether your callback utilises these values is up to your
-        implementation.  For example:
-
-        >>> def make_csr(**kw):
-        ...     print '  make_csr(%r)' % (kw,)  # Note output below
-        ...     return 'Certificate Signing Request'
-        ...
-        >>> csr = Bytes('csr', create_default=make_csr)
-
-        Your ``create_default`` callback will be called with whatever keyword
-        arguments are passed to `Param.get_default()`.  For example:
-
-        >>> kw = dict(arbitrary='Keyword', arguments='Here')
-        >>> csr.get_default(**kw)
-          make_csr({'arguments': 'Here', 'arbitrary': 'Keyword'})
-        'Certificate Signing Request'
-
-        And your ``create_default`` callback is called even if
-        `Param.get_default()` is called with *zero* keyword arguments.
-        For example:
-
-        >>> csr.get_default()
-          make_csr({})
-        'Certificate Signing Request'
-
-        The ``create_default`` callback will most likely be used as a
-        pre-execute hook to perform some special client-side operation.  For
-        example, the ``csr`` parameter above might make a call to
-        ``/usr/bin/openssl``.  However, often a ``create_default`` callback
-        could also be implemented as a ``default_from`` callback.  When this is
-        the case, a ``default_from`` callback should be used as they are more
-        structured and therefore less error-prone.
-
-        The ``default_from`` and ``create_default`` keyword arguments are
-        mutually exclusive.  If you provide both, a ``ValueError`` will be
-        raised.  For example:
-
-        >>> homedir = Str('home',
-        ...     default_from=lambda login: '/home/%s' % login,
-        ...     create_default=lambda **kw: '/lets/use/this',
-        ... )
-        Traceback (most recent call last):
-          ...
-        ValueError: Str('home'): cannot have both 'default_from' and 'create_default'
         """
-        if self._get_default is not None:
-            default = self._get_default(**kw)
+        if self.default_from is not None:
+            default = self.default_from(**kw)
             if default is not None:
                 try:
                     return self.convert(self.normalize(default))

ipalib/plugins/dns.py

@@ -234,7 +234,7 @@ def _rname_validator(ugettext, zonemgr):
         return unicode(e)
     return None
 
-def _create_zone_serial(**kwargs):
+def _create_zone_serial():
     """ Generate serial number for zones. The format follows RFC 1912 """
     return int('%s01' % time.strftime('%Y%m%d'))
 
@@ -1554,7 +1554,7 @@ class dnszone(LDAPObject):
             label=_('SOA serial'),
             doc=_('SOA record serial number'),
             minvalue=1,
-            create_default=_create_zone_serial,
+            default_from=_create_zone_serial,
             autofill=True,
         ),
         Int('idnssoarefresh',

ipalib/plugins/passwd.py

@@ -69,7 +69,7 @@ class passwd(Command):
             label=_('User name'),
             primary_key=True,
             autofill=True,
-            create_default=lambda **kw: util.get_current_principal(),
+            default_from=lambda: util.get_current_principal(),
             normalizer=lambda value: normalize_principal(value),
         ),
         Password('password',

ipaserver/plugins/join.py

@@ -52,7 +52,7 @@ class join(Command):
             validate_host,
             cli_name='hostname',
             doc=_("The hostname to register as"),
-            create_default=lambda **kw: unicode(util.get_fqdn()),
+            default_from=lambda: unicode(util.get_fqdn()),
             autofill=True,
             #normalizer=lamda value: value.lower(),
         ),
@@ -60,7 +60,7 @@ class join(Command):
     takes_options= (
         Str('realm',
             doc=_("The IPA realm"),
-            create_default=lambda **kw: get_realm(),
+            default_from=lambda: get_realm(),
             autofill=True,
         ),
         Str('nshardwareplatform?',

make-lint

@@ -56,9 +56,9 @@ class IPATypeChecker(TypeChecker):
         'ipalib.plugins.misc.env': ['env'],
         'ipalib.parameters.Param': ['cli_name', 'cli_short_name', 'label',
             'doc', 'required', 'multivalue', 'primary_key', 'normalizer',
-            'default', 'default_from', 'create_default', 'autofill', 'query',
-            'attribute', 'include', 'exclude', 'flags', 'hint', 'alwaysask',
-            'sortorder', 'csv', 'csv_separator', 'csv_skipspace'],
+            'default', 'default_from', 'autofill', 'query', 'attribute',
+            'include', 'exclude', 'flags', 'hint', 'alwaysask', 'sortorder',
+            'csv', 'csv_separator', 'csv_skipspace'],
         'ipalib.parameters.Bool': ['truths', 'falsehoods'],
         'ipalib.parameters.Int': ['minvalue', 'maxvalue'],
         'ipalib.parameters.Decimal': ['minvalue', 'maxvalue', 'precision'],

makeapi

@@ -45,7 +45,6 @@ PARAM_IGNORED_KW_ATTRIBUTES = ('label',
                                'normalizer',
                                'encoder',
                                'default_from',
-                               'create_default',
                                'hint',
                                'flags',
                                'sortorder',)

tests/test_ipalib/test_parameters.py

@@ -64,6 +64,16 @@ class test_DefaultFrom(ClassChecker):
         e = raises(TypeError, self.cls, callback, 'givenname', 17)
         assert str(e) == TYPE_ERROR % ('keys', str, 17, int)
 
+        # Test that ValueError is raised when inferring keys from a callback
+        # which has *args:
+        e = raises(ValueError, self.cls, lambda foo, *args: None)
+        assert str(e) == "callback: variable-length argument list not allowed"
+
+        # Test that ValueError is raised when inferring keys from a callback
+        # which has **kwargs:
+        e = raises(ValueError, self.cls, lambda foo, **kwargs: None)
+        assert str(e) == "callback: variable-length argument list not allowed"
+
     def test_repr(self):
         """
         Test the `ipalib.parameters.DefaultFrom.__repr__` method.
@@ -185,8 +195,6 @@ class test_Param(ClassChecker):
         assert o.normalizer is None
         assert o.default is None
         assert o.default_from is None
-        assert o.create_default is None
-        assert o._get_default is None
         assert o.autofill is False
         assert o.query is False
         assert o.attribute is False
@@ -250,16 +258,6 @@ class test_Param(ClassChecker):
         assert str(e) == \
             "Param('my_param'): takes no such kwargs: 'ape', 'great'"
 
-        # Test that ValueError is raised if you provide both default_from and
-        # create_default:
-        e = raises(ValueError, self.cls, 'my_param',
-            default_from=lambda first, last: first[0] + last,
-            create_default=lambda **kw: 'The Default'
-        )
-        assert str(e) == '%s: cannot have both %r and %r' % (
-            "Param('my_param')", 'default_from', 'create_default',
-        )
-
         # Test that ValueError is raised if you provide both include and
         # exclude:
         e = raises(ValueError, self.cls, 'my_param',
@@ -276,15 +274,11 @@ class test_Param(ClassChecker):
         e = raises(ValueError, self.cls, 'my_param', csv=True)
         assert str(e) == '%s: cannot have csv without multivalue' % "Param('my_param')"
 
-        # Test that _get_default gets set:
-        call1 = lambda first, last: first[0] + last
-        call2 = lambda **kw: 'The Default'
-        o = self.cls('my_param', default_from=call1)
-        assert o.default_from.callback is call1
-        assert o._get_default is o.default_from
-        o = self.cls('my_param', create_default=call2)
-        assert o.create_default is call2
-        assert o._get_default is call2
+        # Test that default_from gets set:
+        call = lambda first, last: first[0] + last
+        o = self.cls('my_param', default_from=call)
+        assert type(o.default_from) is parameters.DefaultFrom
+        assert o.default_from.callback is call
 
     def test_repr(self):
         """
@@ -579,7 +573,7 @@ class test_Param(ClassChecker):
 
     def test_get_default(self):
         """
-        Test the `ipalib.parameters.Param._get_default` method.
+        Test the `ipalib.parameters.Param.get_default` method.
         """
         class PassThrough(object):
             value = None
@@ -624,17 +618,6 @@ class test_Param(ClassChecker):
         assert o._convert_scalar.value is default
         assert o.normalizer.value is default
 
-        # Test with create_default:
-        o = Str('my_str',
-            normalizer=PassThrough(),
-            default=u'Static Default',
-            create_default=lambda **kw: u'The created default',
-        )
-        default = o.get_default(first=u'john', last='doe')
-        assert_equal(default, u'The created default')
-        assert o._convert_scalar.value is default
-        assert o.normalizer.value is default
-
     def test_split_csv(self):
         """
         Test the `ipalib.parameters.Param.split_csv` method with csv.