1# These comments let tutorial-asyncio.rst include this code in sections.
2# -- setup-start --
3import asyncio
4
5from aiohttp import web
6from motor.motor_asyncio import AsyncIOMotorClient
7
8
9@asyncio.coroutine
10def setup_db():
11    db = AsyncIOMotorClient().test
12    yield from db.pages.drop()
13    html = '<html><body>{}</body></html>'
14    yield from db.pages.insert_one({'_id': 'page-one',
15                                    'body': html.format('Hello!')})
16
17    yield from db.pages.insert_one({'_id': 'page-two',
18                                    'body': html.format('Goodbye.')})
19
20    return db
21# -- setup-end --
22
23
24# -- handler-start --
25@asyncio.coroutine
26def page_handler(request):
27    # If the visitor gets "/pages/page-one", then page_name is "page-one".
28    page_name = request.match_info.get('page_name')
29
30    # Retrieve the long-lived database handle.
31    db = request.app['db']
32
33    # Find the page by its unique id.
34    document = yield from db.pages.find_one(page_name)
35
36    if not document:
37        return web.HTTPNotFound(text='No page named {!r}'.format(page_name))
38
39    return web.Response(body=document['body'].encode(),
40                        content_type='text/html')
41# -- handler-end --
42
43# -- main-start --
44loop = asyncio.get_event_loop()
45db = loop.run_until_complete(setup_db())
46app = web.Application()
47app['db'] = db
48# Route requests to the page_handler() coroutine.
49app.router.add_get('/pages/{page_name}', page_handler)
50web.run_app(app)
51# -- main-end --
52