django-micro 1.8.0
Django as a microframework
License: BSD
Keywords: django microframework

============
Django Micro
============

.. image::
    https://img.shields.io/pypi/v/django-micro.svg
    :target: https://pypi.python.org/pypi/django-micro

.. image::
    https://img.shields.io/badge/status-stable-brightgreen.svg

Django Micro is lightweight wrapper around Django that turns it to the microframework for writing small applications in a single file.

**tl;dr:** See the example_ of full-featured application.


What works
==========

- `Configuration`_
- `Views and routes`_
- `Models and migrations`_
- `Management commands`_
- `Custom template tags`_
- `Testing`_
- `Admin interface`_
- Third party apps


Installation
============

.. code-block::

    $ pip install django-micro


Quick start
===========

Create ``app.py`` file with following content.

.. code-block:: python

    from django_micro import configure, route, run
    from django.http import HttpResponse

    DEBUG = True
    configure(locals())


    @route('', name='homepage')
    def homepage(request):
        name = request.GET.get('name', 'World')
        return HttpResponse('Hello, {}!'.format(name))


    application = run()

Run the application.

.. code-block::

    $ python app.py runserver

**Note:** Parent directory of the ``app.py`` file must have a valid python module name. Under the hood, Micro adds that directory to ``INSTALLED_APPS`` and uses it as a regular Django application.


Compatibility
=============

The latest relase of django-micro supports only the latest stable release of Django. This is the only way to keep codebase of django-micro clean, without hacks for different versions of Django.

- **Django version:** >=2.0, <2.1
- **Python version:** >=3.4


Run and deployment
==================

On the localhost the application runs with the built-in ``runserver`` command and deploys as a standard WSGI application.

.. code-block::

    $ python app.py runserver
    $ gunicorn example.app --bind localhost:8000
    $ uwsgi --module example.app --http localhost:8000

This behaviour is provided by the single string: ``application = run()`` which actually just a shortcut for the following code.

.. code-block:: python

    if __name__ == '__main__':
        from django.core.management import execute_from_command_line
        execute_from_command_line(sys.argv)
    else:
        from django.core.wsgi import get_wsgi_application
        application = get_wsgi_application()


Configuration
=============

The call of the ``configure`` function must be placed at the top of your application above the definition of views, models, and imports of other modules. It may violate PEP8, but this is the only way to make it works. You can’t define models or import models from another application until Django is configured.

I recommend to define all the configuration in the global namespace and call ``configure`` with ``locals()`` argument. Don’t worry, configure takes only *UPPERCASE* variables.

.. code-block:: python

    from django_micro import configure

    DEBUG = True

    configure(locals())


Views and routes
================

Routing is wrapped in a single function ``route``. You can use it as a decorator.

.. code-block:: python

    from django_micro import route

    @route('blog/<int:year>/', name='year_archive')
    def year_archive(request, year):
        return HttpResponse('hello')

Or as a regular function.

.. code-block:: python

    def year_archive(request):
        return HttpResponse('hello')

    route('blog/<int:year>/', year_archive, name='year_archive')

Also ``route`` may be used with class-based views.

.. code-block:: python

    @route('blog/<int:year>/', name='year_archive')
    class YearArchiveView(View):
        def get(request, year):
            return HttpResponse('hello')

    # or directly
    route('blog/<int:year>/', YearArchiveView.as_view(), name='year_archive')

Micro uses the new simplified routing syntax which was introduced in Django 2.0. But if you’d like to use the regex-based routing syntax, just add ``regex=True`` to the decorator.

.. code-block:: python

    @route(r'^articles/(?P<year>[0-9]{4})/$', regex=True)
    def year_archive(request, year):
        return HttpResponse('hello')

You always can access the ``urlpatterns`` for the use low-level API.

.. code-block:: python

    from django.urls import path
    import django_micro as micro

    micro.urlpatterns += [
        path('', homepage, name='homepage'),
    ]


**Note:** You can include third-party apps into Micro’s ``urlpatterns``, but currently can’t use Micro as a third-party app. Micro is a singleton, and you can’t create more that one instance of it.


Models and migrations
=====================

Micro works well with models and migrations. Just define model in your ``app.py`` file. If you need migrations, create ``migrations`` directory next to the ``app.py`` and call ``python app.py makemigrations``.

.. code-block::

    blog
    ├── __init__.py
    ├── app.py
    └── migrations
        ├── __init__.py
        └── 0001_initial.py

.. code-block:: python

    from django.db import models

    class Post(models.Model):
        title = models.CharField(max_length=255)

        class Meta:
            app_label = 'blog'

**Note:** You always need to set ``app_label`` attribute in ``Meta`` of your models. For example, if application placed in ``blog/app.py``, app_label should be ``blog``.

For getting ``app_label`` you can use ``get_app_label`` shortcut.

.. code-block:: python

    from django_micro import get_app_label

    class Meta:
        app_label = get_app_label()

You also can place models separately in ``models.py`` file. In this case ``app_label`` is not required, but this is not a micro-way ;)


Management commands
===================

Now you can create any management command without creating a file in ``yourapp/management/commands``. Just defne command class in your ``app.py`` and wrap it to ``@command`` decorator.

.. code-block:: python

    from django.core.management.base import BaseCommand
    from django_micro import command

    @command('print_hello')
    class PrintHelloCommand(BaseCommand):
        def handle(self, *args, **options):
            self.stdout.write('Hello, Django!')

You also can create function-based commands.

.. code-block:: python

    from django_micro import command

    @command
    def print_hello(cmd, **options):
        cmd.stdout.write('Hello, Django!')

Unfortunately, the ``command`` decorator uses a few dirty hacks for command registration. But everything works fine if you don’t think about it ;)


Custom template tags
====================

Use ``template`` for register template tags. It works same as a ``register`` object in tag library file.

.. code-block:: python

    from django_micro import template

    @template.simple_tag
    def print_hello(name):
        return 'Hello, {}!'

    @template.filter
    def remove_spaces(value):
        return value.replace(' ', '')


You don’t need to use the ``load`` tag. All template tags are global.


Testing
=======

No magick. Use built-in test cases.

.. code-block:: python

    from django.test import TestCase

    class TestIndexView(TestCase):
        def test_success(self):
            response = self.client.get('/')
            self.assertEqual(response.status_code, 200)

To run tests which defined in app.py use the following command:

.. code-block::

    $ python app.py test __main__


Admin interface
===============

Django-admin requires lots of dependencies in apps and middlewares. We’ve realized that it’s not a simple way to add a huge list of apps to your config just to use the admin interface. So we added a shortcut ``django_admin=True`` to the ``configure`` function that automatically includes all the needed dependencies.

.. code-block:: python

    from django.contrib import admin
    from django_micro import configure

    configure(locals(), django_admin=True)


    class Post(models.Model):
        title = models.CharField(max_length=255)
        content = models.TextField(blank=True)
        create_date = models.DateTimeField(auto_now_add=True)

        class Meta:
            app_label = get_app_label()
            ordering = ('-create_date',)


    @admin.register(Post)
    class PostAdmin(admin.ModelAdmin):
        pass


    route('admin/', admin.site.urls)


Who uses django-micro
=====================

- `storagl <https://github.com/zenwalker/storagl>`_ — simple storage for screenshots and other shared files with short direct links


Related projects
================

- importd_ — Popular implementation of django-as-microframework idea, but too  magical and over-engineered in my opinion.

- djmicro_ — Good and lightweight wrapper. I’ve took a few ideas from there. But it’s an experimental, undocumented and doesn’t develop anymore.


.. _example: https://github.com/zenwalker/django-micro/tree/master/example
.. _djmicro: https://github.com/apendleton/djmicro
.. _importd: https://github.com/amitu/importd