summaryrefslogtreecommitdiffstats
path: root/ipalib/crud.py
blob: 833914cfaa2dd4e99afae8065651435b0bc0f898 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
# Authors:
#   Jason Gerard DeRose <jderose@redhat.com>
#
# Copyright (C) 2008  Red Hat
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""
Base classes for standard CRUD operations.

These base classes are for `Method` plugins that provide standard
Create, Retrieve, Updated, and Delete operations (CRUD) for their corresponding
`Object` plugin.  In particuar, these base classes provide logic to
automatically create the plugin args and options by inspecting the params on
their corresponding `Object` plugin.  This provides a single point of definition
for LDAP attributes and enforces a simple, consistent API for CRUD operations.

For example, say we want CRUD operations on a hypothetical "user" entry.  First
we need an `Object` plugin:

>>> from ipalib import Object, Str
>>> class user(Object):
...     takes_params = (
...         Str('login', primary_key=True),
...         Str('first'),
...         Str('last'),
...         Str('ipauniqueid', flags=['no_create', 'no_update']),
...     )
...

Next we need `Create`, `Retrieve`, `Updated`, and `Delete` plugins, and
optionally a `Search` plugin.  For brevity, we'll just define `Create` and
`Retrieve` plugins:

>>> from ipalib import crud
>>> class user_add(crud.Create):
...     pass
...
>>> class user_show(crud.Retrieve):
...     pass
...

Now we'll register the plugins and finalize the `plugable.API` instance:

>>> from ipalib import create_api
>>> api = create_api()
>>> api.register(user)
>>> api.register(user_add)
>>> api.register(user_show)
>>> api.finalize()

First, notice that our ``user`` `Object` has the params we defined with the
``takes_params`` tuple:

>>> list(api.Object.user.params)
['login', 'first', 'last', 'ipauniqueid']
>>> api.Object.user.params.login
Str('login', primary_key=True)

Although we defined neither ``takes_args`` nor ``takes_options`` for our
``user_add`` plugin, the `Create` base class automatically generated them for
us:

>>> list(api.Command.user_add.args)
['login']
>>> list(api.Command.user_add.options)
['first', 'last', 'all', 'raw', 'version']

Notice that ``'ipauniqueid'`` isn't included in the options for our ``user_add``
plugin.  This is because of the ``'no_create'`` flag we used when defining the
``ipauniqueid`` param.  Often times there are LDAP attributes that are
automatically created by the server and therefor should not be supplied as an
option to the `Create` plugin.  Often these same attributes shouldn't be
update-able either, in which case you can also supply the ``'no_update'`` flag,
as we did with our ``ipauniqueid`` param.  Lastly, you can also use the ``'no_search'`` flag for attributes that shouldn't be search-able (because, for
example, the attribute isn't indexed).

As with our ``user_add` plugin, we defined neither ``takes_args`` nor
``takes_options`` for our ``user_show`` plugin; instead the `Retrieve` base
class created them for us:

>>> list(api.Command.user_show.args)
['login']
>>> list(api.Command.user_show.options)
['all', 'raw', 'version']

As you can see, `Retrieve` plugins take a single argument (the primary key) and
no options.  If needed, you can still specify options for your `Retrieve` plugin
with a ``takes_options`` tuple.

Flags like ``'no_create'`` remove LDAP attributes from those that can be
supplied as *input* to a `Method`, but they don't effect the attributes that can
be returned as *output*.  Regardless of what flags have been used, the output
entry (or list of entries) can contain all the attributes defined on the
`Object` plugin (in our case, the above ``user.params``).

For example, compare ``user.params`` with ``user_add.output_params`` and
``user_show.output_params``:

>>> list(api.Object.user.params)
['login', 'first', 'last', 'ipauniqueid']
>>> list(api.Command.user_add.output_params)
['login', 'first', 'last', 'ipauniqueid']
>>> list(api.Command.user_show.output_params)
['login', 'first', 'last', 'ipauniqueid']

Note that the above are all equal.
"""

from frontend import Method, Object
import backend, frontend, parameters, output


class Create(Method):
    """
    Create a new entry.
    """

    has_output = output.standard_entry

    def get_args(self):
        if self.obj.primary_key:
            yield self.obj.primary_key.clone(attribute=True)

    def get_options(self):
        if self.extra_options_first:
            for option in super(Create, self).get_options():
                yield option
        for option in self.obj.params_minus(self.args):
            attribute = 'virtual_attribute' not in option.flags
            if 'no_create' in option.flags:
                continue
            if 'ask_create' in option.flags:
                yield option.clone(
                    attribute=attribute, query=True, required=False,
                    autofill=False, alwaysask=True
                )
            else:
                yield option.clone(attribute=attribute)
        if not self.extra_options_first:
            for option in super(Create, self).get_options():
                yield option


class PKQuery(Method):
    """
    Base class for `Retrieve`, `Update`, and `Delete`.
    """

    def get_args(self):
        if self.obj.primary_key:
            yield self.obj.primary_key.clone(attribute=True, query=True)


class Retrieve(PKQuery):
    """
    Retrieve an entry by its primary key.
    """

    has_output = output.standard_entry


class Update(PKQuery):
    """
    Update one or more attributes on an entry.
    """

    has_output = output.standard_entry

    def get_options(self):
        if self.extra_options_first:
            for option in super(Update, self).get_options():
                yield option
        for option in self.obj.params_minus_pk():
            attribute = 'virtual_attribute' not in option.flags
            if 'no_update' in option.flags:
                continue
            if 'ask_update' in option.flags:
                yield option.clone(
                    attribute=attribute, query=True, required=False,
                    autofill=False, alwaysask=True
                )
            elif 'req_update' in option.flags:
                yield option.clone(
                    attribute=attribute, required=True, alwaysask=False,
                )
            else:
                yield option.clone(attribute=attribute, required=False, autofill=False)
        if not self.extra_options_first:
            for option in super(Update, self).get_options():
                yield option


class Delete(PKQuery):
    """
    Delete one or more entries.
    """

    has_output = output.standard_delete


class Search(Method):
    """
    Retrieve all entries that match a given search criteria.
    """

    has_output = output.standard_list_of_entries

    def get_args(self):
        yield parameters.Str('criteria?')

    def get_options(self):
        if self.extra_options_first:
            for option in super(Search, self).get_options():
                yield option
        for option in self.obj.params_minus(self.args):
            attribute = 'virtual_attribute' not in option.flags
            if 'no_search' in option.flags:
                continue
            if 'ask_search' in option.flags:
                yield option.clone(
                    attribute=attribute, query=True, required=False,
                    autofill=False, alwaysask=True
                )
            elif isinstance(option, parameters.Flag):
                yield option.clone_retype(
                    option.name, parameters.Bool,
                    attribute=attribute, query=True, required=False, autofill=False
                )
            else:
                yield option.clone(
                    attribute=attribute, query=True, required=False, autofill=False
                )
        if not self.extra_options_first:
            for option in super(Search, self).get_options():
                yield option


class CrudBackend(backend.Connectible):
    """
    Base class defining generic CRUD backend API.
    """

    def create(self, **kw):
        """
        Create a new entry.

        This method should take key word arguments representing the
        attributes the created entry will have.

        If this methods constructs the primary_key internally, it should raise
        an exception if the primary_key was passed.  Likewise, if this method
        requires the primary_key to be passed in from the caller, it should
        raise an exception if the primary key was *not* passed.

        This method should return a dict of the exact entry as it was created
        in the backing store, including any automatically created attributes.
        """
        raise NotImplementedError('%s.create()' % self.name)

    def retrieve(self, primary_key, attributes):
        """
        Retrieve an existing entry.

        This method should take a two arguments: the primary_key of the
        entry in question and a list of the attributes to be retrieved.
        If the list of attributes is None then all non-operational
        attributes will be returned.

        If such an entry exists, this method should return a dict
        representing that entry.  If no such entry exists, this method
        should return None.
        """
        raise NotImplementedError('%s.retrieve()' % self.name)

    def update(self, primary_key, **kw):
        """
        Update an existing entry.

        This method should take one required argument, the primary_key of the
        entry to modify, plus optional keyword arguments for each of the
        attributes being updated.

        This method should return a dict representing the entry as it now
        exists in the backing store.  If no such entry exists, this method
        should return None.
        """
        raise NotImplementedError('%s.update()' % self.name)

    def delete(self, primary_key):
        """
        Delete an existing entry.

        This method should take one required argument, the primary_key of the
        entry to delete.
        """
        raise NotImplementedError('%s.delete()' % self.name)

    def search(self, **kw):
        """
        Return entries matching specific criteria.

        This method should take keyword arguments representing the search
        criteria.  If a key is the name of an entry attribute, the value
        should be treated as a filter on that attribute.  The meaning of
        keys outside this namespace is left to the implementation.

        This method should return and iterable containing the matched
        entries, where each entry is a dict.  If no entries are matched,
        this method should return an empty iterable.
        """
        raise NotImplementedError('%s.search()' % self.name)