sanic/docs/sanic/routing.md

Routing

Routing allows the user to specify handler functions for different URL endpoints.

A basic route looks like the following, where app is an instance of the Sanic class:

from sanic.response import json

@app.route("/")
async def test(request):
    return json({ "hello": "world" })

When the url http://server.url/ is accessed (the base url of the server), the final / is matched by the router to the handler function, test, which then returns a JSON object.

Sanic handler functions must be defined using the async def syntax, as they are asynchronous functions.

Request parameters

Sanic comes with a basic router that supports request parameters.

To specify a parameter, surround it with angle quotes like so: <PARAM>. Request parameters will be passed to the route handler functions as keyword arguments.

from sanic.response import text

@app.route('/tag/<tag>')
async def tag_handler(request, tag):
	return text('Tag - {}'.format(tag))

To specify a type for the parameter, add a :type after the parameter name, inside the quotes. If the parameter does not match the specified type, Sanic will throw a NotFound exception, resulting in a 404: Page not found error on the URL.

from sanic.response import text

@app.route('/number/<integer_arg:int>')
async def integer_handler(request, integer_arg):
	return text('Integer - {}'.format(integer_arg))

@app.route('/number/<number_arg:number>')
async def number_handler(request, number_arg):
	return text('Number - {}'.format(number_arg))

@app.route('/person/<name:[A-z]>')
async def person_handler(request, name):
	return text('Person - {}'.format(name))

@app.route('/folder/<folder_id:[A-z0-9]{0,4}>')
async def folder_handler(request, folder_id):
	return text('Folder - {}'.format(folder_id))

HTTP request types

By default, a route defined on a URL will be used for all requests to that URL. However, the @app.route decorator accepts an optional parameter, methods, which restricts the handler function to the HTTP methods in the given list.

from sanic.response import text

@app.route('/post')
async def post_handler(request, methods=['POST']):
	return text('POST request - {}'.format(request.json))

@app.route('/get')
async def GET_handler(request, methods=['GET']):
	return text('GET request - {}'.format(request.args))

The add_route method

As we have seen, routes are often specified using the @app.route decorator. However, this decorator is really just a wrapper for the app.add_route method, which is used as follows:

from sanic.response import text

# Define the handler functions
async def handler1(request):
	return text('OK')

async def handler2(request, name):
	return text('Folder - {}'.format(name))

async def person_handler2(request, name):
	return text('Person - {}'.format(name))

# Add each handler function as a route
app.add_route(handler1, '/test')
app.add_route(handler2, '/folder/<name>')
app.add_route(person_handler2, '/person/<name:[A-z]>', methods=['GET'])