From fe1a1eb79bf0f1df8bbc56d2402e32061af79d06 Mon Sep 17 00:00:00 2001 From: Sebastian Silva Date: Wed, 12 Oct 2011 00:54:31 +0000 Subject: Tidy up code a bit - added documentation --- (limited to 'studio/static/doc/flask-docs/_sources/patterns/packages.txt') diff --git a/studio/static/doc/flask-docs/_sources/patterns/packages.txt b/studio/static/doc/flask-docs/_sources/patterns/packages.txt new file mode 100644 index 0000000..79fd2c5 --- /dev/null +++ b/studio/static/doc/flask-docs/_sources/patterns/packages.txt @@ -0,0 +1,115 @@ +.. _larger-applications: + +Larger Applications +=================== + +For larger applications it's a good idea to use a package instead of a +module. That is quite simple. Imagine a small application looks like +this:: + + /yourapplication + /yourapplication.py + /static + /style.css + /templates + layout.html + index.html + login.html + ... + +Simple Packages +--------------- + +To convert that into a larger one, just create a new folder +`yourapplication` inside the existing one and move everything below it. +Then rename `yourapplication.py` to `__init__.py`. (Make sure to delete +all `.pyc` files first, otherwise things would most likely break) + +You should then end up with something like that:: + + /yourapplication + /yourapplication + /__init__.py + /static + /style.css + /templates + layout.html + index.html + login.html + ... + +But how do you run your application now? The naive ``python +yourapplication/__init__.py`` will not work. Let's just say that Python +does not want modules in packages to be the startup file. But that is not +a big problem, just add a new file called `runserver.py` next to the inner +`yourapplication` folder with the following contents:: + + from yourapplication import app + app.run(debug=True) + +What did we gain from this? Now we can restructure the application a bit +into multiple modules. The only thing you have to remember is the +following quick checklist: + +1. the `Flask` application object creation has to be in the + `__init__.py` file. That way each module can import it safely and the + `__name__` variable will resolve to the correct package. +2. all the view functions (the ones with a :meth:`~flask.Flask.route` + decorator on top) have to be imported when in the `__init__.py` file. + Not the object itself, but the module it is in. Import the view module + **after the application object is created**. + +Here's an example `__init__.py`:: + + from flask import Flask + app = Flask(__name__) + + import yourapplication.views + +And this is what `views.py` would look like:: + + from yourapplication import app + + @app.route('/') + def index(): + return 'Hello World!' + +You should then end up with something like that:: + + /yourapplication + /runserver.py + /yourapplication + /__init__.py + /views.py + /static + /style.css + /templates + layout.html + index.html + login.html + ... + +.. admonition:: Circular Imports + + Every Python programmer hates them, and yet we just added some: + circular imports (That's when two modules depend on each other. In this + case `views.py` depends on `__init__.py`). Be advised that this is a + bad idea in general but here it is actually fine. The reason for this is + that we are not actually using the views in `__init__.py` and just + ensuring the module is imported and we are doing that at the bottom of + the file. + + There are still some problems with that approach but if you want to use + decorators there is no way around that. Check out the + :ref:`becomingbig` section for some inspiration how to deal with that. + + +.. _working-with-modules: + +Working with Blueprints +----------------------- + +If you have larger applications it's recommended to divide them into +smaller groups where each group is implemented with the help of a +blueprint. For a gentle introduction into this topic refer to the +:ref:`blueprints` chapter of the documentation. -- cgit v0.9.1