47 lines
1.2 KiB
ReStructuredText
47 lines
1.2 KiB
ReStructuredText
.. _hooks:
|
|
|
|
Hooks
|
|
=====
|
|
|
|
Falcon supports both **before** and **after** hooks. You install a hook simply by
|
|
applying one of the decorators below either to an individual responder or
|
|
to an entire resource.
|
|
|
|
For example, suppose you had a hook like this:
|
|
|
|
.. code:: python
|
|
|
|
def validate_image_type(req, resp, params):
|
|
if req.content_type not in ALLOWED_IMAGE_TYPES:
|
|
msg = 'Image type not allowed. Must be PNG, JPEG, or GIF'
|
|
raise falcon.HTTPBadRequest('Bad request', msg)
|
|
|
|
You would attach the hook to an ``on_post`` responder like so:
|
|
|
|
.. code:: python
|
|
|
|
@falcon.before(validate_image_type)
|
|
def on_post(self, req, resp):
|
|
pass
|
|
|
|
Or, if you had a hook that you would like to applied to *all*
|
|
responders for a given resource, you could install the hook like this:
|
|
|
|
.. code:: python
|
|
|
|
@falcon.before(extract_project_id)
|
|
class Message(object):
|
|
pass
|
|
|
|
And you can apply hooks globally by passing them into the API class
|
|
initializer (note that this does not require the use of a decorator):
|
|
|
|
.. code:: python
|
|
|
|
falcon.API(before=[extract_project_id])
|
|
|
|
|
|
.. automodule:: falcon
|
|
:members: before, after
|
|
:undoc-members:
|