Add custom HTTP method in falcon?

Question

As many as HTTP frameworks support using the custom method and custom HTTP status code to be used inside the codes, I wonder that is it possible to do the same thing with Falcon?

I tried:

class MyResource:
    def on_obtain(self, req, resp):
        # do some thing

and I also add it to the API routes, but when I call this API I get HTTP/1.1 400 Bad Request with this body:

{"title":"Bad request","description":"Invalid HTTP method"}

my question is that is it possible to define obtain on this resource?

Answer 1

I think you need to use Custom Routers. Just an example:

class Resource:

    def on_get(self, req, resp):
        resp.body = req.method
        resp.status = falcon.HTTP_200

    def on_example(self, req, resp):
        resp.body = req.method
        resp.status = falcon.HTTP_200

class MyRouter(routing.DefaultRouter):
    # this is just demonstration that my solution works
    # I added request method into method_map
    def add_route(self, uri_template, method_map, resource):
        super().add_route(uri_template, method_map, resource)
        method_map['EXAMPLE'] = resource.on_example

    def find(self, uri, req=None):
        return super().find(uri, req)

api = falcon.API(router=MyRouter())  # just set your router
test = Resource()
api.add_route('/test', test)

Let's check:

curl -X EXAMPLE http://127.0.0.1:8000/test
EXAMPLE⏎
curl http://127.0.0.1:8000/test
GET⏎

So, all what you need is just create Router and implement add_route() / find() methods. Hope you understand what I mean.

Answer 2

Falcon 3 has built-in support for custom HTTP methods.

You can either

• use the environment variable FALCON_CUSTOM_HTTP_METHODS which is a comma-delimited list of custom methods:

  export FALCON_CUSTOM_HTTP_METHODS=EXAMPLE,PURGE
  

• or add it programmatically to the COMBINED_METHODS constant:

  import falcon.constants
  falcon.constants.COMBINED_METHODS += ['EXAMPLE', 'PURGE']