"""A simple number and datetime addition JSON API.
Run the app:
$ python examples/flaskrestful_example.py
Try the following with httpie (a cURL-like utility, http://httpie.org):
$ pip install httpie
$ http GET :5001/
$ http GET :5001/ name==Ada
$ http POST :5001/add x=40 y=2
$ http POST :5001/dateadd value=1973-04-10 addend=63
$ http POST :5001/dateadd value=2014-10-23 addend=525600 unit=minutes
"""
import datetime as dt
from flask import Flask
from flask_restful import Api, Resource
from webargs import fields, validate
from webargs.flaskparser import use_args, use_kwargs, parser, abort
app = Flask(__name__)
api = Api(app)
class IndexResource(Resource):
"""A welcome page."""
hello_args = {"name": fields.Str(missing="Friend")}
@use_args(hello_args)
def get(self, args):
return {"message": "Welcome, {}!".format(args["name"])}
class AddResource(Resource):
"""An addition endpoint."""
add_args = {"x": fields.Float(required=True), "y": fields.Float(required=True)}
@use_kwargs(add_args)
def post(self, x, y):
"""An addition endpoint."""
return {"result": x + y}
class DateAddResource(Resource):
dateadd_args = {
"value": fields.Date(required=False),
"addend": fields.Int(required=True, validate=validate.Range(min=1)),
"unit": fields.Str(
missing="days", validate=validate.OneOf(["minutes", "days"])
),
}
@use_kwargs(dateadd_args)
def post(self, value, addend, unit):
"""A date adder endpoint."""
value = value or dt.datetime.utcnow()
if unit == "minutes":
delta = dt.timedelta(minutes=addend)
else:
delta = dt.timedelta(days=addend)
result = value + delta
return {"result": result.isoformat()}
# This error handler is necessary for usage with Flask-RESTful
@parser.error_handler
def handle_request_parsing_error(err, req, schema, *, error_status_code, error_headers):
"""webargs error handler that uses Flask-RESTful's abort function to return
a JSON error response to the client.
"""
abort(error_status_code, errors=err.messages)
if __name__ == "__main__":
api.add_resource(IndexResource, "/")
api.add_resource(AddResource, "/add")
api.add_resource(DateAddResource, "/dateadd")
app.run(port=5001, debug=True)