a1e1a925e7
Misc. tweaks to the docs in preparation for 0.2.0rc1, including:
* Edit middleware docs for clarity and correctness
* Use Warning or Tip headers instead of Note, where appropriate
* Update sphinx config regarding author and copyright
50 lines
1.3 KiB
ReStructuredText
50 lines
1.3 KiB
ReStructuredText
.. _hooks:
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Hooks
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=====
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Falcon supports *before* and *after* hooks. You install a hook simply by
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applying one of the decorators below, either to an individual responder or
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to an entire resource.
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For example, consider this hook that validates a POST request for
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an image resource:
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.. code:: python
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def validate_image_type(req, resp, resource, params):
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if req.content_type not in ALLOWED_IMAGE_TYPES:
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msg = 'Image type not allowed. Must be PNG, JPEG, or GIF'
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raise falcon.HTTPBadRequest('Bad request', msg)
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You would attach this hook to an ``on_post`` responder like so:
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.. code:: python
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@falcon.before(validate_image_type)
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def on_post(self, req, resp):
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pass
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Or, suppose you had a hook that you would like to apply to *all*
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responders for a given resource. In that case, you would simply
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decorate the resource class:
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.. code:: python
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@falcon.before(extract_project_id)
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class Message(object):
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def on_post(self, req, resp):
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pass
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def on_get(self, req, resp):
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pass
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Falcon :ref:`middleware components <middleware>` can also be used to insert
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logic before and after requests. However, unlike hooks,
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:ref:`middleware components <middleware>` are triggered **globally** for all
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requests.
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.. automodule:: falcon
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:members: before, after
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:undoc-members:
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