django-rest-framework/rest_framework/compat.py
2020-08-17 13:26:56 -07:00

160 lines
4.3 KiB
Python

"""
The `compat` module provides support for backwards compatibility with older
versions of Django/Python, and compatibility wrappers around optional packages.
"""
from django.conf import settings
from django.views.generic import View
def unicode_http_header(value):
# Coerce HTTP header value to unicode.
if isinstance(value, bytes):
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()
# django.contrib.postgres requires psycopg2
try:
from django.contrib.postgres import fields as postgres_fields
except ImportError:
postgres_fields = None
# coreapi is required for CoreAPI schema generation
try:
import coreapi
except ImportError:
coreapi = None
# uritemplate is required for OpenAPI and CoreAPI schema generation
try:
import uritemplate
except ImportError:
uritemplate = None
# coreschema is optional
try:
import coreschema
except ImportError:
coreschema = None
# pyyaml is optional
try:
import yaml
except ImportError:
yaml = None
# requests is optional
try:
import requests
except ImportError:
requests = None
# 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 (version 3.0+ required)
try:
import markdown
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 <h2>.
"""
extensions = [HEADERID_EXT_PATH]
extension_configs = {
HEADERID_EXT_PATH: {
LEVEL_PARAM: '2'
}
}
md = markdown.Markdown(
extensions=extensions, extension_configs=extension_configs
)
md_filter_add_syntax_highlight(md)
return md.convert(text)
except ImportError:
apply_markdown = None
markdown = None
try:
import pygments
from pygments.formatters import HtmlFormatter
from pygments.lexers import TextLexer, get_lexer_by_name
def pygments_highlight(text, lang, style):
lexer = get_lexer_by_name(lang, stripall=False)
formatter = HtmlFormatter(nowrap=True, style=style)
return pygments.highlight(text, lexer, formatter)
def pygments_css(style):
formatter = HtmlFormatter(style=style)
return formatter.get_style_defs('.highlight')
except ImportError:
pygments = None
def pygments_highlight(text, lang, style):
return text
def pygments_css(style):
return None
if markdown is not None and pygments is not None:
# starting from this blogpost and modified to support current markdown extensions API
# https://zerokspot.com/weblog/2008/06/18/syntax-highlighting-in-markdown-with-pygments/
import re
from markdown.preprocessors import Preprocessor
class CodeBlockPreprocessor(Preprocessor):
pattern = re.compile(
r'^\s*``` *([^\n]+)\n(.+?)^\s*```', re.M | re.S)
formatter = HtmlFormatter()
def run(self, lines):
def repl(m):
try:
lexer = get_lexer_by_name(m.group(1))
except (ValueError, NameError):
lexer = TextLexer()
code = m.group(2).replace('\t', ' ')
code = pygments.highlight(code, lexer, self.formatter)
code = code.replace('\n\n', '\n&nbsp;\n').replace('\n', '<br />').replace('\\@', '@')
return '\n\n%s\n\n' % code
ret = self.pattern.sub(repl, "\n".join(lines))
return ret.split("\n")
def md_filter_add_syntax_highlight(md):
md.preprocessors.register(CodeBlockPreprocessor(), 'highlight', 40)
return True
else:
def md_filter_add_syntax_highlight(md):
return False
# `separators` argument to `json.dumps()` differs between 2.x and 3.x
# See: https://bugs.python.org/issue22767
SHORT_SEPARATORS = (',', ':')
LONG_SEPARATORS = (', ', ': ')
INDENT_SEPARATORS = (',', ': ')