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
|
# -*- coding: utf-8 -*-
# Copyright 2014-2016 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
""" This module contains base REST classes for constructing REST servlets. """
from synapse.api.errors import SynapseError, Codes
import logging
import simplejson
logger = logging.getLogger(__name__)
def parse_integer(request, name, default=None, required=False):
"""Parse an integer parameter from the request string
Args:
request: the twisted HTTP request.
name (str): the name of the query parameter.
default (int|None): value to use if the parameter is absent, defaults
to None.
required (bool): whether to raise a 400 SynapseError if the
parameter is absent, defaults to False.
Returns:
int|None: An int value or the default.
Raises:
SynapseError: if the parameter is absent and required, or if the
parameter is present and not an integer.
"""
return parse_integer_from_args(request.args, name, default, required)
def parse_integer_from_args(args, name, default=None, required=False):
if name in args:
try:
return int(args[name][0])
except:
message = "Query parameter %r must be an integer" % (name,)
raise SynapseError(400, message)
else:
if required:
message = "Missing integer query parameter %r" % (name,)
raise SynapseError(400, message, errcode=Codes.MISSING_PARAM)
else:
return default
def parse_boolean(request, name, default=None, required=False):
"""Parse a boolean parameter from the request query string
Args:
request: the twisted HTTP request.
name (str): the name of the query parameter.
default (bool|None): value to use if the parameter is absent, defaults
to None.
required (bool): whether to raise a 400 SynapseError if the
parameter is absent, defaults to False.
Returns:
bool|None: A bool value or the default.
Raises:
SynapseError: if the parameter is absent and required, or if the
parameter is present and not one of "true" or "false".
"""
if name in request.args:
try:
return {
"true": True,
"false": False,
}[request.args[name][0]]
except:
message = (
"Boolean query parameter %r must be one of"
" ['true', 'false']"
) % (name,)
raise SynapseError(400, message)
else:
if required:
message = "Missing boolean query parameter %r" % (name,)
raise SynapseError(400, message, errcode=Codes.MISSING_PARAM)
else:
return default
def parse_string(request, name, default=None, required=False,
allowed_values=None, param_type="string"):
"""Parse a string parameter from the request query string.
Args:
request: the twisted HTTP request.
name (str): the name of the query parameter.
default (str|None): value to use if the parameter is absent, defaults
to None.
required (bool): whether to raise a 400 SynapseError if the
parameter is absent, defaults to False.
allowed_values (list[str]): List of allowed values for the string,
or None if any value is allowed, defaults to None
Returns:
str|None: A string value or the default.
Raises:
SynapseError if the parameter is absent and required, or if the
parameter is present, must be one of a list of allowed values and
is not one of those allowed values.
"""
return parse_string_from_args(
request.args, name, default, required, allowed_values, param_type,
)
def parse_string_from_args(args, name, default=None, required=False,
allowed_values=None, param_type="string"):
if name in args:
value = args[name][0]
if allowed_values is not None and value not in allowed_values:
message = "Query parameter %r must be one of [%s]" % (
name, ", ".join(repr(v) for v in allowed_values)
)
raise SynapseError(400, message)
else:
return value
else:
if required:
message = "Missing %s query parameter %r" % (param_type, name)
raise SynapseError(400, message, errcode=Codes.MISSING_PARAM)
else:
return default
def parse_json_value_from_request(request):
"""Parse a JSON value from the body of a twisted HTTP request.
Args:
request: the twisted HTTP request.
Returns:
The JSON value.
Raises:
SynapseError if the request body couldn't be decoded as JSON.
"""
try:
content_bytes = request.content.read()
except:
raise SynapseError(400, "Error reading JSON content.")
try:
content = simplejson.loads(content_bytes)
except simplejson.JSONDecodeError:
raise SynapseError(400, "Content not JSON.", errcode=Codes.NOT_JSON)
return content
def parse_json_object_from_request(request):
"""Parse a JSON object from the body of a twisted HTTP request.
Args:
request: the twisted HTTP request.
Raises:
SynapseError if the request body couldn't be decoded as JSON or
if it wasn't a JSON object.
"""
content = parse_json_value_from_request(request)
if type(content) != dict:
message = "Content must be a JSON object."
raise SynapseError(400, message, errcode=Codes.BAD_JSON)
return content
class RestServlet(object):
""" A Synapse REST Servlet.
An implementing class can either provide its own custom 'register' method,
or use the automatic pattern handling provided by the base class.
To use this latter, the implementing class instead provides a `PATTERN`
class attribute containing a pre-compiled regular expression. The automatic
register method will then use this method to register any of the following
instance methods associated with the corresponding HTTP method:
on_GET
on_PUT
on_POST
on_DELETE
on_OPTIONS
Automatically handles turning CodeMessageExceptions thrown by these methods
into the appropriate HTTP response.
"""
def register(self, http_server):
""" Register this servlet with the given HTTP server. """
if hasattr(self, "PATTERNS"):
patterns = self.PATTERNS
for method in ("GET", "PUT", "POST", "OPTIONS", "DELETE"):
if hasattr(self, "on_%s" % (method,)):
method_handler = getattr(self, "on_%s" % (method,))
http_server.register_paths(method, patterns, method_handler)
else:
raise NotImplementedError("RestServlet must register something.")
|
