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
|
"""A simple number and datetime addition JSON API.
Demonstrates different strategies for parsing arguments
with the FalconParser.
Run the app:
$ pip install gunicorn
$ gunicorn examples.falcon_example:app
Try the following with httpie (a cURL-like utility, http://httpie.org):
$ pip install httpie
$ http GET :8000/
$ http GET :8000/ name==Ada
$ http POST :8000/add x=40 y=2
$ http POST :8000/dateadd value=1973-04-10 addend=63
$ http POST :8000/dateadd value=2014-10-23 addend=525600 unit=minutes
"""
import datetime as dt
import falcon
from webargs import fields, validate
from webargs.core import json
from webargs.falconparser import parser, use_args, use_kwargs
### Middleware and hooks ###
class JSONTranslator:
def process_response(self, req, resp, resource):
if "result" not in req.context:
return
resp.body = json.dumps(req.context["result"])
def add_args(argmap, **kwargs):
def hook(req, resp, params):
req.context["args"] = parser.parse(argmap, req=req, **kwargs)
return hook
### Resources ###
class HelloResource:
"""A welcome page."""
hello_args = {"name": fields.Str(load_default="Friend", location="query")}
@use_args(hello_args)
def on_get(self, req, resp, args):
req.context["result"] = {"message": "Welcome, {}!".format(args["name"])}
class AdderResource:
"""An addition endpoint."""
adder_args = {"x": fields.Float(required=True), "y": fields.Float(required=True)}
@use_kwargs(adder_args)
def on_post(self, req, resp, x, y):
req.context["result"] = {"result": x + y}
class DateAddResource:
"""A datetime adder endpoint."""
dateadd_args = {
"value": fields.Date(required=False),
"addend": fields.Int(required=True, validate=validate.Range(min=1)),
"unit": fields.Str(
load_default="days", validate=validate.OneOf(["minutes", "days"])
),
}
@falcon.before(add_args(dateadd_args))
def on_post(self, req, resp):
"""A datetime adder endpoint."""
args = req.context["args"]
value = args["value"] or dt.datetime.utcnow()
if args["unit"] == "minutes":
delta = dt.timedelta(minutes=args["addend"])
else:
delta = dt.timedelta(days=args["addend"])
result = value + delta
req.context["result"] = {"result": result.isoformat()}
app = falcon.API(middleware=[JSONTranslator()])
app.add_route("/", HelloResource())
app.add_route("/add", AdderResource())
app.add_route("/dateadd", DateAddResource())
|
