aio.web.server 0.0.3

Detailed documentation
**********************

aio.web.server
==============

Web server for the aio_ asyncio framework

.. _aio: https://github.com/phlax/aio



Build status
------------

.. image:: https://travis-ci.org/phlax/aio.web.server.svg?branch=master
:target: https://travis-ci.org/phlax/aio.web.server


Installation
------------
Install with:

.. code:: bash

pip install aio.web.server


Configuration
-------------

Example configuration for a hello world web page

.. code:: ini

[server/test]
factory = aio.web.server.factory
port = 8080

[web/test/page]
match = /
route = my.example.handler

And the corresponding route handler

.. code:: python

import asyncio
import aiohttp

@asyncio.coroutine
def handler(request):
return aiohttp.web.Response(body=b"Hello, web world")


Running
-------

Run with the aio command

.. code:: bash

aio run



aio.web.server usage
-------------


Configuration
-------------

Let's create a config defining a factory method and using the aio.web.server.protocol for the protocol

In the following configuration example a server named "example-1" is set up.

Any sections that start with "web/example-1/" will be treated as route definitions.

The route definition should provide a "match" and a "route" at a minimum.

The route is given a name derived from the section name. In this case "homepage"

>>> web_server_config = """
... [aio]
... log_level: ERROR
...
... [server/example]
... factory = aio.web.server.factory
... port = 7070
...
... [web/example/homepage]
... match = /
... route = aio.web.server.tests._example_handler
... """

>>> import asyncio
>>> import aiohttp
>>> import aio.web.server.tests
>>> from aio.app.runner import runner
>>> from aio.testing import aiofuturetest

>>> @asyncio.coroutine
... def handler(request):
... return aiohttp.web.Response(body=b"Hello, web world")

>>> aio.web.server.tests._example_handler = handler

>>> @aiofuturetest(sleep=1)
... def run_web_server(config, request_page="http://localhost:7070"):
... yield from runner(['run'], config_string=config)
...
... @asyncio.coroutine
... def call_web_server():
... result = yield from (
... yield from aiohttp.request(
... "GET", request_page)).read()
...
... print(result.decode())
...
... return call_web_server

>>> run_web_server(web_server_config)
Hello, web world


Accessing web apps
------------------

You can access a webapp by name

>>> import aio.web.server
>>> aio.web.server.apps['example']
<Application>

>>> aio.web.server.apps['example']['name']
'example'

Let's clear the web apps, this will also call aio.app.clear()

>>> aio.web.server.clear()
>>> aio.web.server.apps
{}

>>> print(aio.app.config, aio.app.signals)
None None


Static directory
----------------

The "web/" section takes a static_url and a static_dir option for hosting static files

>>> config_static = """
... [aio]
... log_level: ERROR
...
... [server/test]
... factory: aio.web.server.factory
... port: 7070
...
... [web/test]
... static_url: /static
... static_dir: %s
... """

>>> import os
>>> import tempfile

>>> with tempfile.TemporaryDirectory() as tmp:
... with open(os.path.join(tmp, "test.css"), 'w') as cssfile:
... res = cssfile.write("body {}")
...
... run_web_server(
... config_static % tmp,
... request_page="http://localhost:7070/static/test.css")
body {}

And clear up...

>>> aio.web.server.clear()


Routes, templates and fragments
-------------------------------

aio.web.server uses jinja2 templates under the hood

On setup aio searches the paths of modules listed in the aio:modules option for folders named "templates" and loads any templates it finds from there

>>> config_template = """
... [aio]
... modules = aio.web.server.tests
... log_level: ERROR
...
... [server/example-2]
... factory: aio.web.server.factory
... port: 7070
...
... [web/example-2/homepage]
... match = /
... route = aio.web.server.tests._example_route_handler
... """


Routes
~~~~~~

By decorating a function with @aio.web.server.route, the function is called with the request and the configuration for the route that is being handled

>>> @aio.web.server.route("test_template.html")
... def route_handler(request, config):
... return {
... 'message': 'Hello, world'}

>>> aio.web.server.tests._example_route_handler = route_handler

>>> run_web_server(config_template)
<html>
<body>
Hello, world
</body>
</html>

>>> aio.web.server.clear()

Templates
~~~~~~~~~

A route handler can defer to other templates, for example according to the path.

The @aio.web.server.route decorator does not require a template, but in that case the decorated function must return an aiohttp.web.StreamResponse object

A route always takes 2 arguments - request and config, a template can take any arguments that it requires

While you can use an @aio.web.template as a route handler, doing so would bypass the normal logging and request handling operations

>>> example_config = """
... [aio]
... modules = aio.web.server.tests
... log_level: ERROR
...
... [server/example-3]
... factory: aio.web.server.factory
... port: 7070
...
... [web/example-3/paths]
... match = /{path:.*}
... route = aio.web.server.tests._example_route_handler
... """

>>> @aio.web.server.template("test_template.html")
... def template_handler_1(request):
... return {'message': "Hello, world from template handler 1"}

>>> @aio.web.server.template("test_template.html")
... def template_handler_2(request):
... return {'message': "Hello, world from template handler 2"}

>>> @aio.web.server.route
... def route_handler(request, config):
...
... if request.path == "/path1":
... return (yield from template_handler_1(request))
...
... elif request.path == "/path2":
... return (yield from template_handler_2(request))

>>> aio.web.server.tests._example_route_handler = route_handler

>>> run_web_server(
... example_config,
... request_page="http://localhost:7070/path1")
<html>
<body>
Hello, world from template handler 1
</body>
</html>

>>> aio.web.server.clear()

>>> run_web_server(
... example_config,
... request_page="http://localhost:7070/path2")
<html>
<body>
Hello, world from template handler 2
</body>
</html>

>>> aio.web.server.clear()

Fragments
~~~~~~~~~

Both routes and templates are expected to return a full html page, or an html response object.

Fragments render a snippet of code, and are not expected to return a full page.

Fragments cannot return an html response object, but can raise an html error if required

>>> example_config = """
... [aio]
... modules = aio.web.server.tests
... log_level: ERROR
...
... [server/example-3]
... factory: aio.web.server.factory
... port: 7070
...
... [web/example-3/paths]
... match = /
... route = aio.web.server.tests._example_route_handler
... """

>>> @aio.web.server.fragment("fragments/test_fragment.html")
... def fragment_handler(request, test_list):
... return {'test_list': test_list}

>>> @aio.web.server.template("test_template.html")
... def template_handler(request, test_list):
... return {'message': (yield from fragment_handler(request, test_list))}

>>> @aio.web.server.route
... def route_handler(request, config):
...
... return (yield from template_handler(request, ["foo", "bar", "baz"]))

>>> aio.web.server.tests._example_route_handler = route_handler

>>> run_web_server(
... example_config,
... request_page="http://localhost:7070/")
<html>
<body>
<ul>
<li>foo</li><li>bar</li><li>baz</li>
</ul>
</body>
</html>