Allows multiple apps to override the same management command in Django
© 2014-2015 Thomas Khyn
MCMO stands for 'Management Command Multiple Override'. This django app allows multiple apps to override the same management command without evicting any.
Supports Django 1.4 to 1.8 and matching Python 2 and 3 versions.
As straightforward as it can be, using pip:
pip install django-mcmo
In your manage.py
file, replace the line:
from django.core import management
by:
from mcmo import management
You can now use applications that concurrently define overrides for
django.core management
commands. Both commands will be called.
For example, if you are using djinga and django-extra_keywords, which
both override Django's makemessages
management command, both commands from
both applications will be called subsequently.
The first command which will be called will be the one relative to the
application in the latest position in the INSTALLED_APPS
.
In your manage.py is automatically generated (e.g. if you are using buildout with djangorecipebook or djangorecipe), simply make sure that the statement:
import mcmo
is executed before calling django.management.execute_from_command_line
.
Importing the package patches the django.core.management
module, which
functions are then enabled for multiple-override support.
The same-name overrides should all derive from the same command class, or at
least from on of Django's base command classes (AppCommand
,
LabelCommand
or NoArgsCommand
).
django-mcmo
will raise a warning (but the execution will carry on) in case
of subclassing inconsistencies. For example, if the command cmd
in app1
inherits from AppCommand
and the command cmd
in app2
inherits from
NoArgsCommand
. Indeed, as only one command is likely to be executed in that
situation, the obtained results may not be consistent as it will depend on the
relative position of the apps in INSTALLED_APPS
or raise an exception
regarding arguments presence, absence or type.
In practice, same-name commands will only be met when two 3rd party apps override a Django core management command. They will therefore derive from the same Command base class, and cause no issue in 99.9% of the cases.
django-mcmo
may also emit warning messages if the same option is
explicitly added in the same command of two distinct apps with command classes
not being subclasses of each other.