|
1
|
|
|
""" |
|
2
|
|
|
This module contains decorators that facilitate the `jsons` functions in an |
|
3
|
|
|
alternative fashion. |
|
4
|
|
|
""" |
|
5
|
|
|
from inspect import signature, Parameter, isawaitable, iscoroutinefunction |
|
6
|
|
|
|
|
7
|
|
|
from jsons import JsonSerializable, dump, load, loads, loadb, dumps, dumpb |
|
8
|
|
|
from jsons.exceptions import InvalidDecorationError |
|
9
|
|
|
|
|
10
|
|
|
|
|
11
|
|
|
def loaded( |
|
12
|
|
|
parameters=True, |
|
13
|
|
|
returnvalue=True, |
|
14
|
|
|
fork_inst=JsonSerializable, |
|
15
|
|
|
loader=load, |
|
16
|
|
|
**kwargs): |
|
17
|
|
|
""" |
|
18
|
|
|
Return a decorator that can call `jsons.load` upon all parameters and the |
|
19
|
|
|
return value of the decorated function. |
|
20
|
|
|
|
|
21
|
|
|
|
|
22
|
|
|
**Example**: |
|
23
|
|
|
|
|
24
|
|
|
>>> from datetime import datetime |
|
25
|
|
|
>>> @loaded() |
|
26
|
|
|
... def func(arg: datetime) -> datetime: |
|
27
|
|
|
... # arg is now of type datetime. |
|
28
|
|
|
... return '2018-10-04T21:57:00Z' # This will become a datetime. |
|
29
|
|
|
>>> res = func('2018-10-04T21:57:00Z') |
|
30
|
|
|
>>> type(res).__name__ |
|
31
|
|
|
'datetime' |
|
32
|
|
|
|
|
33
|
|
|
:param parameters: determines whether parameters should be taken into |
|
34
|
|
|
account. |
|
35
|
|
|
:param returnvalue: determines whether the return value should be taken |
|
36
|
|
|
into account. |
|
37
|
|
|
:param fork_inst: if given, it uses this fork of ``JsonSerializable``. |
|
38
|
|
|
:param kwargs: any keyword arguments that should be passed on to |
|
39
|
|
|
`jsons.load` |
|
40
|
|
|
:param loader: the load function which must be one of (``load``, |
|
41
|
|
|
``loads``, ``loadb``) |
|
42
|
|
|
:return: a decorator that can be placed on a function. |
|
43
|
|
|
""" |
|
44
|
|
|
if loader not in (load, loads, loadb): |
|
45
|
|
|
raise InvalidDecorationError("The 'loader' argument must be one of: " |
|
46
|
|
|
"jsons.load, jsons.loads, jsons.loadb") |
|
47
|
|
|
return _get_decorator(parameters, returnvalue, fork_inst, loader, kwargs) |
|
48
|
|
|
|
|
49
|
|
|
|
|
50
|
|
|
def dumped( |
|
51
|
|
|
parameters=True, |
|
52
|
|
|
returnvalue=True, |
|
53
|
|
|
fork_inst=JsonSerializable, |
|
54
|
|
|
dumper=dump, |
|
55
|
|
|
**kwargs): |
|
56
|
|
|
""" |
|
57
|
|
|
Return a decorator that can call `jsons.dump` upon all parameters and the |
|
58
|
|
|
return value of the decorated function. |
|
59
|
|
|
|
|
60
|
|
|
|
|
61
|
|
|
**Example**: |
|
62
|
|
|
|
|
63
|
|
|
>>> from datetime import datetime |
|
64
|
|
|
>>> @dumped() |
|
65
|
|
|
... def func(arg): |
|
66
|
|
|
... # arg is now of type str. |
|
67
|
|
|
... return datetime.now() |
|
68
|
|
|
>>> res = func(datetime.now()) |
|
69
|
|
|
>>> type(res).__name__ |
|
70
|
|
|
'str' |
|
71
|
|
|
|
|
72
|
|
|
:param parameters: determines whether parameters should be taken into |
|
73
|
|
|
account. |
|
74
|
|
|
:param returnvalue: determines whether the return value should be taken |
|
75
|
|
|
into account. |
|
76
|
|
|
:param fork_inst: if given, it uses this fork of ``JsonSerializable``. |
|
77
|
|
|
:param kwargs: any keyword arguments that should be passed on to |
|
78
|
|
|
`jsons.dump` |
|
79
|
|
|
:param dumper: the dump function which must be one of (``dump``, |
|
80
|
|
|
``dumps``, ``dumpb``) |
|
81
|
|
|
:return: a decorator that can be placed on a function. |
|
82
|
|
|
""" |
|
83
|
|
|
if dumper not in (dump, dumps, dumpb): |
|
84
|
|
|
raise InvalidDecorationError("The 'dumper' argument must be one of: " |
|
85
|
|
|
"jsons.dump, jsons.dumps, jsons.dumpb") |
|
86
|
|
|
return _get_decorator(parameters, returnvalue, fork_inst, dumper, kwargs) |
|
87
|
|
|
|
|
88
|
|
|
|
|
89
|
|
|
def _get_decorator(parameters, returnvalue, fork_inst, mapper, mapper_kwargs): |
|
90
|
|
|
def _decorator(decorated): |
|
91
|
|
|
_validate_decoration(decorated, fork_inst) |
|
92
|
|
|
args = [decorated, parameters, returnvalue, |
|
93
|
|
|
fork_inst, mapper, mapper_kwargs] |
|
94
|
|
|
wrapper = (_get_async_wrapper(*args) if iscoroutinefunction(decorated) |
|
95
|
|
|
else _get_wrapper(*args)) |
|
96
|
|
|
return wrapper |
|
97
|
|
|
|
|
98
|
|
|
return _decorator |
|
99
|
|
|
|
|
100
|
|
|
|
|
101
|
|
|
def _get_wrapper( |
|
102
|
|
|
decorated, |
|
103
|
|
|
parameters, |
|
104
|
|
|
returnvalue, |
|
105
|
|
|
fork_inst, |
|
106
|
|
|
mapper, |
|
107
|
|
|
mapper_kwargs): |
|
108
|
|
|
def _wrapper(*args, **kwargs): |
|
109
|
|
|
result = _run_decorated(decorated, mapper if parameters else None, |
|
110
|
|
|
fork_inst, args, kwargs, mapper_kwargs) |
|
111
|
|
|
if returnvalue: |
|
112
|
|
|
result = _map_returnvalue(result, decorated, fork_inst, mapper, |
|
113
|
|
|
mapper_kwargs) |
|
114
|
|
|
return result |
|
115
|
|
|
|
|
116
|
|
|
return _wrapper |
|
117
|
|
|
|
|
118
|
|
|
|
|
119
|
|
|
def _get_async_wrapper( |
|
120
|
|
|
decorated, |
|
121
|
|
|
parameters, |
|
122
|
|
|
returnvalue, |
|
123
|
|
|
fork_inst, |
|
124
|
|
|
mapper, |
|
125
|
|
|
mapper_kwargs): |
|
126
|
|
|
async def _async_wrapper(*args, **kwargs): |
|
127
|
|
|
result = _run_decorated(decorated, mapper if parameters else None, |
|
128
|
|
|
fork_inst, args, kwargs, mapper_kwargs) |
|
129
|
|
|
if isawaitable(result): |
|
130
|
|
|
result = await result |
|
131
|
|
|
if returnvalue: |
|
132
|
|
|
result = _map_returnvalue(result, decorated, fork_inst, mapper, |
|
133
|
|
|
mapper_kwargs) |
|
134
|
|
|
return result |
|
135
|
|
|
|
|
136
|
|
|
return _async_wrapper |
|
137
|
|
|
|
|
138
|
|
|
|
|
139
|
|
|
def _get_params_sig(args, func): |
|
140
|
|
|
sig = signature(func) |
|
141
|
|
|
params = sig.parameters |
|
142
|
|
|
param_names = [param_name for param_name in params] |
|
143
|
|
|
result = [(args[i], params[param_names[i]]) for i in range(len(args))] |
|
144
|
|
|
return result |
|
145
|
|
|
|
|
146
|
|
|
|
|
147
|
|
|
def _map_args(args, decorated, fork_inst, mapper, mapper_kwargs): |
|
148
|
|
|
params_sig = _get_params_sig(args, decorated) |
|
149
|
|
|
new_args = [] |
|
150
|
|
|
for arg, sig in params_sig: |
|
151
|
|
|
if sig.name in ('self', 'cls') and hasattr(arg, decorated.__name__): |
|
152
|
|
|
# `decorated` is a method and arg is either `self` or `cls`. |
|
153
|
|
|
new_arg = arg |
|
154
|
|
|
else: |
|
155
|
|
|
cls = sig.annotation if sig.annotation != Parameter.empty else None |
|
156
|
|
|
new_arg = mapper(arg, cls=cls, fork_inst=fork_inst, |
|
157
|
|
|
**mapper_kwargs) |
|
158
|
|
|
|
|
159
|
|
|
new_args.append(new_arg) |
|
160
|
|
|
return new_args |
|
161
|
|
|
|
|
162
|
|
|
|
|
163
|
|
|
def _map_returnvalue(returnvalue, decorated, fork_inst, mapper, mapper_kwargs): |
|
164
|
|
|
return_annotation = signature(decorated).return_annotation |
|
165
|
|
|
cls = return_annotation if return_annotation != Parameter.empty else None |
|
166
|
|
|
result = mapper(returnvalue, cls=cls, fork_inst=fork_inst, **mapper_kwargs) |
|
167
|
|
|
return result |
|
168
|
|
|
|
|
169
|
|
|
|
|
170
|
|
|
def _run_decorated(decorated, mapper, fork_inst, args, kwargs, mapper_kwargs): |
|
171
|
|
|
new_args = args |
|
172
|
|
|
if mapper: |
|
173
|
|
|
new_args = _map_args(args, decorated, fork_inst, mapper, mapper_kwargs) |
|
174
|
|
|
result = decorated(*new_args, **kwargs) |
|
175
|
|
|
return result |
|
176
|
|
|
|
|
177
|
|
|
|
|
178
|
|
|
def _validate_decoration(decorated, fork_inst): |
|
179
|
|
|
if isinstance(decorated, staticmethod): |
|
180
|
|
|
fork_inst._warn('You cannot decorate a static- or classmethod. ' |
|
181
|
|
|
'You can still obtain the desired behavior by ' |
|
182
|
|
|
'decorating your method first and then place ' |
|
183
|
|
|
'@staticmethod/@classmethod on top (switching the ' |
|
184
|
|
|
'order).', 'decorated-static') |
|
185
|
|
|
raise InvalidDecorationError( |
|
186
|
|
|
'Cannot decorate a static- or classmethod.') |
|
187
|
|
|
if isinstance(decorated, type): |
|
188
|
|
|
raise InvalidDecorationError('Cannot decorate a class.') |
|
189
|
|
|
|