django-rest-framework/rest_framework/compat.py

260 lines
8.3 KiB
Python

"""
The `compat` module provides support for backwards compatibility with older
versions of django/python, and compatibility wrappers around optional packages.
"""
# flake8: noqa
from __future__ import unicode_literals
import inspect
import django
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.db import connection, transaction
from django.forms import FilePathField as DjangoFilePathField
from django.test.client import FakePayload
from django.utils import six
from django.utils.encoding import force_text
from django.utils.six.moves.urllib.parse import urlparse as _urlparse
try:
import importlib
except ImportError:
from django.utils import importlib
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 total_seconds(timedelta):
# TimeDelta.total_seconds() is only available in Python 2.7
if hasattr(timedelta, 'total_seconds'):
return timedelta.total_seconds()
else:
return (timedelta.days * 86400.0) + float(timedelta.seconds) + (timedelta.microseconds / 1000000.0)
# OrderedDict only available in Python 2.7.
# This will always be the case in Django 1.7 and above, as these versions
# no longer support Python 2.6.
# For Django <= 1.6 and Python 2.6 fall back to SortedDict.
try:
from collections import OrderedDict
except ImportError:
from django.utils.datastructures import SortedDict as OrderedDict
# HttpResponseBase only exists from 1.5 onwards
try:
from django.http.response import HttpResponseBase
except ImportError:
from django.http import HttpResponse as HttpResponseBase
# contrib.postgres only supported from 1.8 onwards.
try:
from django.contrib.postgres import fields as postgres_fields
except ImportError:
postgres_fields = None
# request only provides `resolver_match` from 1.5 onwards.
def get_resolver_match(request):
try:
return request.resolver_match
except AttributeError:
# Django < 1.5
from django.core.urlresolvers import resolve
return resolve(request.path_info)
# django-filter is optional
try:
import django_filters
except ImportError:
django_filters = None
if django.VERSION >= (1, 6):
def clean_manytomany_helptext(text):
return text
else:
# Up to version 1.5 many to many fields automatically suffix
# the `help_text` attribute with hardcoded text.
def clean_manytomany_helptext(text):
if text.endswith(' Hold down "Control", or "Command" on a Mac, to select more than one.'):
text = text[:-69]
return text
# 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
if 'guardian' in settings.INSTALLED_APPS:
try:
import guardian
import guardian.shortcuts # Fixes #1624
except ImportError:
pass
def get_model_name(model_cls):
try:
return model_cls._meta.model_name
except AttributeError:
# < 1.6 used module_name instead of model_name
return model_cls._meta.module_name
# Support custom user models in Django 1.5+
try:
from django.contrib.auth import get_user_model
except ImportError:
from django.contrib.auth.models import User
get_user_model = lambda: User
# View._allowed_methods only present from 1.5 onwards
if django.VERSION >= (1, 5):
from django.views.generic import View
else:
from django.views.generic import View as DjangoView
class View(DjangoView):
def _allowed_methods(self):
return [m.upper() for m in self.http_method_names if hasattr(self, m)]
# MinValueValidator, MaxValueValidator et al. only accept `message` in 1.8+
if django.VERSION >= (1, 8):
from django.core.validators import MinValueValidator, MaxValueValidator
from django.core.validators import MinLengthValidator, MaxLengthValidator
else:
from django.core.validators import MinValueValidator as DjangoMinValueValidator
from django.core.validators import MaxValueValidator as DjangoMaxValueValidator
from django.core.validators import MinLengthValidator as DjangoMinLengthValidator
from django.core.validators import MaxLengthValidator as DjangoMaxLengthValidator
class MinValueValidator(DjangoMinValueValidator):
def __init__(self, *args, **kwargs):
self.message = kwargs.pop('message', self.message)
super(MinValueValidator, self).__init__(*args, **kwargs)
class MaxValueValidator(DjangoMaxValueValidator):
def __init__(self, *args, **kwargs):
self.message = kwargs.pop('message', self.message)
super(MaxValueValidator, self).__init__(*args, **kwargs)
class MinLengthValidator(DjangoMinLengthValidator):
def __init__(self, *args, **kwargs):
self.message = kwargs.pop('message', self.message)
super(MinLengthValidator, self).__init__(*args, **kwargs)
class MaxLengthValidator(DjangoMaxLengthValidator):
def __init__(self, *args, **kwargs):
self.message = kwargs.pop('message', self.message)
super(MaxLengthValidator, self).__init__(*args, **kwargs)
# URLValidator only accepts `message` in 1.6+
if django.VERSION >= (1, 6):
from django.core.validators import URLValidator
else:
from django.core.validators import URLValidator as DjangoURLValidator
class URLValidator(DjangoURLValidator):
def __init__(self, *args, **kwargs):
self.message = kwargs.pop('message', self.message)
super(URLValidator, self).__init__(*args, **kwargs)
# EmailValidator requires explicit regex prior to 1.6+
if django.VERSION >= (1, 6):
from django.core.validators import EmailValidator
else:
from django.core.validators import EmailValidator as DjangoEmailValidator
from django.core.validators import email_re
class EmailValidator(DjangoEmailValidator):
def __init__(self, *args, **kwargs):
super(EmailValidator, self).__init__(email_re, *args, **kwargs)
# 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
def apply_markdown(text):
"""
Simple wrapper around :func:`markdown.markdown` to set the base level
of '#' style headers to <h2>.
"""
extensions = ['headerid(level=2)']
safe_mode = False
md = markdown.Markdown(extensions=extensions, safe_mode=safe_mode)
return md.convert(text)
except ImportError:
apply_markdown = None
# `separators` argument to `json.dumps()` differs between 2.x and 3.x
# See: http://bugs.python.org/issue22767
if six.PY3:
SHORT_SEPARATORS = (',', ':')
LONG_SEPARATORS = (', ', ': ')
INDENT_SEPARATORS = (',', ': ')
else:
SHORT_SEPARATORS = (b',', b':')
LONG_SEPARATORS = (b', ', b': ')
INDENT_SEPARATORS = (b',', b': ')
if django.VERSION >= (1, 8):
from django.db.models import DurationField
from django.utils.dateparse import parse_duration
from django.utils.duration import duration_string
else:
DurationField = duration_string = parse_duration = None
def set_rollback():
if hasattr(transaction, 'set_rollback'):
if connection.settings_dict.get('ATOMIC_REQUESTS', False):
# If running in >=1.6 then mark a rollback as required,
# and allow it to be handled by Django.
if connection.in_atomic_block:
transaction.set_rollback(True)
elif transaction.is_managed():
# Otherwise handle it explicitly if in managed mode.
if transaction.is_dirty():
transaction.rollback()
transaction.leave_transaction_management()
else:
# transaction not managed
pass