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author | Sebastian Silva <sebastian@sugarlabs.org> | 2011-11-16 07:56:19 (GMT) |
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committer | Sebastian Silva <sebastian@sugarlabs.org> | 2011-11-16 07:56:19 (GMT) |
commit | 82511a6fe2d29d50c1cdca4b2abb23ff681a1943 (patch) | |
tree | ff6359d68287417abfaaf49e492e2630239e60c9 /app/static/doc/flask-docs/_sources/shell.txt | |
parent | 61517139f02df2ce417f465dfabdbf5dbe8f4063 (diff) |
Major improvements in IDE usability.
Diffstat (limited to 'app/static/doc/flask-docs/_sources/shell.txt')
-rw-r--r-- | app/static/doc/flask-docs/_sources/shell.txt | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/app/static/doc/flask-docs/_sources/shell.txt b/app/static/doc/flask-docs/_sources/shell.txt new file mode 100644 index 0000000..61b9dc0 --- /dev/null +++ b/app/static/doc/flask-docs/_sources/shell.txt @@ -0,0 +1,93 @@ +.. _shell: + +Working with the Shell +====================== + +.. versionadded:: 0.3 + +One of the reasons everybody loves Python is the interactive shell. It +basically allows you to execute Python commands in real time and +immediately get results back. Flask itself does not come with an +interactive shell, because it does not require any specific setup upfront, +just import your application and start playing around. + +There are however some handy helpers to make playing around in the shell a +more pleasant experience. The main issue with interactive console +sessions is that you're not triggering a request like a browser does which +means that :data:`~flask.g`, :data:`~flask.request` and others are not +available. But the code you want to test might depend on them, so what +can you do? + +This is where some helper functions come in handy. Keep in mind however +that these functions are not only there for interactive shell usage, but +also for unittesting and other situations that require a faked request +context. + +Generally it's recommended that you read the :ref:`request-context` +chapter of the documentation first. + +Creating a Request Context +-------------------------- + +The easiest way to create a proper request context from the shell is by +using the :attr:`~flask.Flask.test_request_context` method which creates +us a :class:`~flask.ctx.RequestContext`: + +>>> ctx = app.test_request_context() + +Normally you would use the `with` statement to make this request object +active, but in the shell it's easier to use the +:meth:`~flask.ctx.RequestContext.push` and +:meth:`~flask.ctx.RequestContext.pop` methods by hand: + +>>> ctx.push() + +From that point onwards you can work with the request object until you +call `pop`: + +>>> ctx.pop() + +Firing Before/After Request +--------------------------- + +By just creating a request context, you still don't have run the code that +is normally run before a request. This might result in your database +being unavailable if you are connecting to the database in a +before-request callback or the current user not being stored on the +:data:`~flask.g` object etc. + +This however can easily be done yourself. Just call +:meth:`~flask.Flask.preprocess_request`: + +>>> ctx = app.test_request_context() +>>> ctx.push() +>>> app.preprocess_request() + +Keep in mind that the :meth:`~flask.Flask.preprocess_request` function +might return a response object, in that case just ignore it. + +To shutdown a request, you need to trick a bit before the after request +functions (triggered by :meth:`~flask.Flask.process_response`) operate on +a response object: + +>>> app.process_response(app.response_class()) +<Response 0 bytes [200 OK]> +>>> ctx.pop() + +The functions registered as :meth:`~flask.Flask.teardown_request` are +automatically called when the context is popped. So this is the perfect +place to automatically tear down resources that were needed by the request +context (such as database connections). + + +Further Improving the Shell Experience +-------------------------------------- + +If you like the idea of experimenting in a shell, create yourself a module +with stuff you want to star import into your interactive session. There +you could also define some more helper methods for common things such as +initializing the database, dropping tables etc. + +Just put them into a module (like `shelltools` and import from there): + +>>> from shelltools import * |