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
|
# 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; version 2 only
#
# 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, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
"""
Base classes for standard CRUD operations.
"""
import backend, frontend, parameters
class Create(frontend.Method):
"""
Create a new 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):
yield option.clone(attribute=True)
if not self.extra_options_first:
for option in super(Create, self).get_options():
yield option
class PKQuery(frontend.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.
"""
class Update(PKQuery):
"""
Update one or more attributes on an 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():
yield option.clone(attribute=True, 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.
"""
class Search(frontend.Method):
"""
Retrieve all entries that match a given search criteria.
"""
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):
yield option.clone(
attribute=True, 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)
|
