""" The `compat` module provides support for backwards compatibility with older versions of Django/Python, and compatibility wrappers around optional packages. """ from __future__ import unicode_literals import inspect import django from django.apps import apps from django.conf import settings from django.core import validators from django.core.exceptions import ImproperlyConfigured from django.db import models from django.utils import six from django.views.generic import View try: from django.urls import ( # noqa URLPattern, URLResolver, ) except ImportError: # Will be removed in Django 2.0 from django.urls import ( # noqa RegexURLPattern as URLPattern, RegexURLResolver as URLResolver, ) def get_regex_pattern(urlpattern): if hasattr(urlpattern, 'pattern'): # Django 2.0 return urlpattern.pattern.regex.pattern else: # Django < 2.0 return urlpattern.regex.pattern def make_url_resolver(regex, urlpatterns): try: # Django 2.0 from django.urls.resolvers import RegexPattern return URLResolver(RegexPattern(regex), urlpatterns) except ImportError: # Django < 2.0 return URLResolver(regex, urlpatterns) def unicode_repr(instance): # Get the repr of an instance, but ensure it is a unicode string # on both python 3 (already the case) and 2 (not the case). if six.PY2: return repr(instance).decode('utf-8') return repr(instance) def unicode_to_repr(value): # Coerce a unicode string to the correct repr return type, depending on # the Python version. We wrap all our `__repr__` implementations with # this and then use unicode throughout internally. if six.PY2: return value.encode('utf-8') return value def unicode_http_header(value): # Coerce HTTP header value to unicode. if isinstance(value, six.binary_type): return value.decode('iso-8859-1') return value def distinct(queryset, base): if settings.DATABASES[queryset.db]["ENGINE"] == "django.db.backends.oracle": # distinct analogue for Oracle users return base.filter(pk__in=set(queryset.values_list('pk', flat=True))) return queryset.distinct() def _resolve_model(obj): """ Resolve supplied `obj` to a Django model class. `obj` must be a Django model class itself, or a string representation of one. Useful in situations like GH #1225 where Django may not have resolved a string-based reference to a model in another model's foreign key definition. String representations should have the format: 'appname.ModelName' """ if isinstance(obj, six.string_types) and len(obj.split('.')) == 2: app_name, model_name = obj.split('.') resolved_model = apps.get_model(app_name, model_name) if resolved_model is None: msg = "Django did not return a model for {0}.{1}" raise ImproperlyConfigured(msg.format(app_name, model_name)) return resolved_model elif inspect.isclass(obj) and issubclass(obj, models.Model): return obj raise ValueError("{0} is not a Django model".format(obj)) # django.contrib.postgres requires psycopg2 try: from django.contrib.postgres import fields as postgres_fields except ImportError: postgres_fields = None # coreapi is optional (Note that uritemplate is a dependency of coreapi) try: import coreapi import uritemplate except (ImportError, SyntaxError): # SyntaxError is possible under python 3.2 coreapi = None uritemplate = None # coreschema is optional try: import coreschema except ImportError: coreschema = None # django-crispy-forms is optional try: import crispy_forms except ImportError: crispy_forms = None # requests is optional try: import requests except ImportError: requests = None # Django-guardian is optional. Import only if guardian is in INSTALLED_APPS # Fixes (#1712). We keep the try/except for the test suite. guardian = None try: if 'guardian' in settings.INSTALLED_APPS: import guardian # noqa except ImportError: pass # PATCH method is not implemented by Django if 'patch' not in View.http_method_names: View.http_method_names = View.http_method_names + ['patch'] # Markdown is optional try: import markdown if markdown.version <= '2.2': HEADERID_EXT_PATH = 'headerid' LEVEL_PARAM = 'level' elif markdown.version < '2.6': HEADERID_EXT_PATH = 'markdown.extensions.headerid' LEVEL_PARAM = 'level' else: HEADERID_EXT_PATH = 'markdown.extensions.toc' LEVEL_PARAM = 'baselevel' def apply_markdown(text): """ Simple wrapper around :func:`markdown.markdown` to set the base level of '#' style headers to