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Injector-enabled Python application microframework

Project description

Build status

Cask is Injector-enabled, Python application microframework modelled after Flask.

It’s purpose is to make the amount of boilerplate you need to write when developing your application smaller. Here’s a simple example:

>>> from cask import Cask
>>> from injector import inject
>>>
>>> def configure(binder):
...     binder.bind(str, to='ABC')
...
>>> @Cask.run_main(modules=[configure])
... @inject(s=str)
... def main(s):
...     print(s)
...
ABC

Cask.run_main (it works both as class and instance method, see below) does the if __name__ == '__main__' check for you. So this

>>> app = Cask()
>>> @app.run_main
... def main():
...     print(111)
...
111

is shorter version of

>>> app = Cask()
>>> @app.main
... def main():
...     print(222)
...
>>> if __name__ == '__main__':
...     app.run()
...
222

Construction

Cask constructor and Cask.run_main class method accept the following optional keyword arguments:

  • modules - iterable of Injector modules, defaults to empty sequence
  • injector- instance of Injector to configure and use, by default new instance will be created for you

Hooks

Cask instance provides the following decorators allowing you to register hooks (note that you can inject into registered functions):

  • Cask.before_main - should expect no parameters, if non-None value is returned application execution main function won’t be executed

  • Cask.after_main - should expect single result parameter and return processed result (modified or not)

  • Cask.exception_handler(ExceptionCLass) - will handle exception raised during the application execution, should expect single argument called e and containing exception value:

    >>> app = Cask()
    >>> @app.exception_handler(Exception)
    ... def handle(e):
    ...     print('got exception %s' % (e,))
    ...
    >>> @app.run_main
    ... def main():
    ...     raise Exception(123)
    ...
    got exception 123
    
  • Cask.main - main function should expect no arguments and may return something

You can, of course, register more than one callable for hooks other than main.

Note

Only first matching exception_handler hook will be called, if any.

Execution

This is what happens when you run Cask-based application:

  1. Injector is configured using provided modules
  2. before_main hooks are called
  3. If before_main hooks didn’t return value different than None, main hook is executed
  4. after_main hooks are called

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Filename, size & hash SHA256 hash help File type Python version Upload date
cask-0.1.1.tar.gz (3.6 kB) Copy SHA256 hash SHA256 Source None Aug 21, 2013

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