django-adminLink to this heading#Aplikacje mogą rejestrować swoje własne akcje w manage.py. Na przykład mógłbyś chcieć dodać akcję manage.py dla aplikacji Django, którą udostępniasz. W tym dokumencie będziemy budować własną komendę closepoll dla aplikacji polls z samouczka.
To do this, add a management/commands directory to the application. Django\nwill register a manage.py command for each Python module in that directory\nwhose name doesn’t begin with an underscore. For example:
polls/\n __init__.py\n models.py\n management/\n __init__.py\n commands/\n __init__.py\n _private.py\n closepoll.py\n tests.py\n views.py\nW tym przykładzie komenda closepoll stanie się dostępna dla każdego projektu, który umieści aplikację polls w INSTALLED_APPS.
Moduł _private.py nie będzie dostępny jako komenda zarządzania.
Jest tylko jedno wymaganie dla closepoll.py – musi definiować klasę Command, która dziedziczy po BaseCommand lub jednej z jej podklas.
Aby zaimplementować komendę, zmień polls/management/commands/closepoll.py, aby wyglądał w ten sposób:
from django.core.management.base import BaseCommand, CommandError\nfrom polls.models import Question as Poll\n\n\nclass Command(BaseCommand):\n help = "Closes the specified poll for voting"\n\n def add_arguments(self, parser):\n parser.add_argument("poll_ids", nargs="+", type=int)\n\n def handle(self, *args, **options):\n for poll_id in options["poll_ids"]:\n try:\n poll = Poll.objects.get(pk=poll_id)\n except Poll.DoesNotExist:\n raise CommandError('Poll "%s" does not exist' % poll_id)\n\n poll.opened = False\n poll.save()\n\n self.stdout.write(\n self.style.SUCCESS('Successfully closed poll "%s"' % poll_id)\n )\nThe new custom command can be called using python manage.py closepoll\n<poll_ids>.
The handle() method takes one or more poll_ids and sets poll.opened\nto False for each one. If the user referenced any nonexistent polls, a\nCommandError is raised. The poll.opened attribute does not exist in\nthe tutorial and was added to\npolls.models.Question for this example.
The same closepoll could be easily modified to delete a given poll instead\nof closing it by accepting additional command line options. These custom\noptions can be added in the add_arguments() method like this:
class Command(BaseCommand):\n def add_arguments(self, parser):\n # Positional arguments\n parser.add_argument("poll_ids", nargs="+", type=int)\n\n # Named (optional) arguments\n parser.add_argument(\n "--delete",\n action="store_true",\n help="Delete poll instead of closing it",\n )\n\n def handle(self, *args, **options):\n # ...\n if options["delete"]:\n poll.delete()\n # ...\nThe option (delete in our example) is available in the options dict\nparameter of the handle method. See the argparse Python documentation\nfor more about add_argument usage.
In addition to being able to add custom command line options, all\nmanagement commands can accept some default options\nsuch as --verbosity and --traceback.
By default, management commands are executed with the current active locale.
\nIf, for some reason, your custom management command must run without an active\nlocale (for example, to prevent translated content from being inserted into\nthe database), deactivate translations using the @no_translations\ndecorator on your handle() method:
from django.core.management.base import BaseCommand, no_translations\n\n\nclass Command(BaseCommand):\n ...\n\n @no_translations\n def handle(self, *args, **options):\n ...\nSince translation deactivation requires access to configured settings, the\ndecorator can’t be used for commands that work without configured settings.
\nInformation on how to test custom management commands can be found in the\ntesting docs.
\nDjango registers the built-in commands and then searches for commands in\nINSTALLED_APPS in reverse. During the search, if a command name\nduplicates an already registered command, the newly discovered command\noverrides the first.
In other words, to override a command, the new command must have the same name\nand its app must be before the overridden command’s app in\nINSTALLED_APPS.
Management commands from third-party apps that have been unintentionally\noverridden can be made available under a new name by creating a new command in\none of your project’s apps (ordered before the third-party app in\nINSTALLED_APPS) which imports the Command of the overridden\ncommand.
The base class from which all management commands ultimately derive.
\nUse this class if you want access to all of the mechanisms which\nparse the command-line arguments and work out what code to call in\nresponse; if you don’t need to change any of that behavior,\nconsider using one of its subclasses.
\nSubclassing the BaseCommand class requires that you implement the\nhandle() method.
All attributes can be set in your derived class and can be used in\nBaseCommand’s subclasses.
A short description of the command, which will be printed in the\nhelp message when the user runs the command\npython manage.py help <command>.
If your command defines mandatory positional arguments, you can customize\nthe message error returned in the case of missing arguments. The default is\noutput by argparse („too few arguments”).
A boolean indicating whether the command outputs SQL statements; if\nTrue, the output will automatically be wrapped with BEGIN; and\nCOMMIT;. Default value is False.
A boolean; if True, the command prints a warning if the set of\nmigrations on disk don’t match the migrations in the database. A warning\ndoesn’t prevent the command from executing. Default value is False.
A list or tuple of tags, e.g. [Tags.staticfiles, Tags.models]. System\nchecks registered in the chosen tags\nwill be checked for errors prior to executing the command. The value\n'__all__' can be used to specify that all system checks should be\nperformed. Default value is '__all__'.
An instance attribute that helps create colored output when writing to\nstdout or stderr. For example:
self.stdout.write(self.style.SUCCESS("..."))\nSee Syntax coloring to learn how to modify the color palette and to\nsee the available styles (use uppercased versions of the „roles” described\nin that section).
\nIf you pass the --no-color option when running your command, all\nself.style() calls will return the original string uncolored.
The default command options to suppress in the help output. This should be\na set of option names (e.g. '--verbosity'). The default values for the\nsuppressed options are still passed.
BaseCommand has a few methods that can be overridden but only\nthe handle() method must be implemented.
Returns a CommandParser instance, which is an\nArgumentParser subclass with a few customizations for\nDjango.
You can customize the instance by overriding this method and calling\nsuper() with kwargs of ArgumentParser parameters.
Entry point to add parser arguments to handle command line arguments passed\nto the command. Custom commands should override this method to add both\npositional and optional arguments accepted by the command. Calling\nsuper() is not needed when directly subclassing BaseCommand.
Returns the Django version, which should be correct for all built-in Django\ncommands. User-supplied commands can override this method to return their\nown version.
\nTries to execute this command, performing system checks if needed (as\ncontrolled by the requires_system_checks attribute). If the command\nraises a CommandError, it’s intercepted and printed to stderr.
The actual logic of the command. Subclasses must implement this method.
\nIt may return a string which will be printed to stdout (wrapped\nby BEGIN; and COMMIT; if output_transaction is True).
Uses the system check framework to inspect the entire Django project for\npotential problems. Serious problems are raised as a CommandError;\nwarnings are output to stderr; minor notifications are output to\nstdout.
If app_configs and tags are both None, all system checks are\nperformed. tags can be a list of check tags, like compatibility or\nmodels.
BaseCommand subclassesLink to this heading#A management command which takes one or more installed application labels as\narguments, and does something with each of them.
\nRather than implementing handle(), subclasses must\nimplement handle_app_config(), which will be called once for\neach application.
Perform the command’s actions for app_config, which will be an\nAppConfig instance corresponding to an application\nlabel given on the command line.
A management command which takes one or more arbitrary arguments (labels) on\nthe command line, and does something with each of them.
\nRather than implementing handle(), subclasses must implement\nhandle_label(), which will be called once for each label.
A string describing the arbitrary arguments passed to the command. The\nstring is used in the usage text and error messages of the command.\nDefaults to 'label'.
Wykonuje działania komendy dla etykiety``label``, którą będzie łańcuch podany w linii komend.
\nKlasa wyjątków wskazująca na problem podczas wykonywania polecenia zarządzania.
\nIf this exception is raised during the execution of a management command from a\ncommand line console, it will be caught and turned into a nicely-printed error\nmessage to the appropriate output stream (i.e., stderr); as a result,\nraising this exception (with a sensible description of the error) is the\npreferred way to indicate that something has gone wrong in the execution of a\ncommand. It accepts the optional returncode argument to customize the exit\nstatus for the management command to exit with, using sys.exit().
If a management command is called from code through\ncall_command(), it’s up to you to catch the\nexception when needed.