api.py

import logging
from tornado import gen, ioloop, web
import queries


class WidgetRequestHandler(web.RequestHandler):

    def initialize(self):
        self.session = queries.TornadoSession()

    @gen.coroutine
    def post(self, *args, **kwargs):
        if 'sku' not in kwargs:
            raise web.HTTPError(404, 'Missing SKU')

        name = self.get_argument('name')
        qty = self.get_argument('qty')
        try:
            yield self.session.query("UPDATE widgets SET name=%(name)s, qty=%(qty)s WHERE sku=%(sku)s",
                                     {'sku': kwargs['sku'], 'name': name, 'qty': qty})
        except queries.IntegrityError as error:
            self.set_status(409)
            if 'duplicate key' in str(error):
                self.finish({'error': "Can not add the same SKU again."})
            else:
                self.finish({'error': str(error)})
        else:
            self.set_status(201)
            self.finish()

    @gen.coroutine
    def get(self, *args, **kwargs):
        data = yield self.session.query("SELECT * FROM widgets WHERE sku=%(sku)s",
                                        {'sku': kwargs['sku']})
        if not data:
            self.set_status(404)
            self.finish({'error': 'widget not found'})
        else:
            self.finish(data[0])

    @gen.coroutine
    def post(self, *args, **kwargs):
        self.finish()

    @gen.coroutine
    def put(self, *args, **kwargs):
        sku = self.get_argument('sku')
        name = self.get_argument('name')
        qty = self.get_argument('qty')
        try:
            yield self.session.query("INSERT INTO widgets VALUES (%s, %s, %s)",
                                     [sku, name, qty])
        except queries.IntegrityError as error:
            self.set_status(409)
            if 'duplicate key' in str(error):
                self.finish({'error': "Can not add the same SKU again."})
            else:
                self.finish({'error': str(error)})
        else:
            self.set_status(201)
            self.finish()


class WidgetsRequestHandler(web.RequestHandler):

    def initialize(self):
        self.session = queries.TornadoSession()

    @gen.coroutine
    def get(self, *args, **kwargs):
        data = yield self.session.query("SELECT * FROM widgets ORDER BY sku")
        self.finish({'widgets': data})


if __name__ == "__main__":
    logging.basicConfig(level=logging.DEBUG)
    application = web.Application([
        (r"/widget", WidgetRequestHandler),
        (r"/widget/(?P<sku>[a-z0-9]{10})", WidgetRequestHandler),
        (r"/widgets", WidgetsRequestHandler)
    ]).listen(8888)
    ioloop.IOLoop.instance().start()