Current File : //snap/core20/2434/lib/python3/dist-packages/jinja2/utils.py
# -*- coding: utf-8 -*-
"""
jinja2.utils
~~~~~~~~~~~~
Utility functions.
:copyright: (c) 2017 by the Jinja Team.
:license: BSD, see LICENSE for more details.
"""
import re
import json
import errno
try:
from collections.abc import deque
except:
from collections import deque
from threading import Lock
from jinja2._compat import text_type, string_types, implements_iterator, \
url_quote
from string import ascii_letters as _letters
from string import digits as _digits
# special singleton representing missing values for the runtime
missing = type('MissingType', (), {'__repr__': lambda x: 'missing'})()
# internal code
internal_code = set()
concat = u''.join
_slash_escape = '\\/' not in json.dumps('/')
def contextfunction(f):
"""This decorator can be used to mark a function or method context callable.
A context callable is passed the active :class:`Context` as first argument when
called from the template. This is useful if a function wants to get access
to the context or functions provided on the context object. For example
a function that returns a sorted list of template variables the current
template exports could look like this::
@contextfunction
def get_exported_names(context):
return sorted(context.exported_vars)
"""
f.contextfunction = True
return f
def evalcontextfunction(f):
"""This decorator can be used to mark a function or method as an eval
context callable. This is similar to the :func:`contextfunction`
but instead of passing the context, an evaluation context object is
passed. For more information about the eval context, see
:ref:`eval-context`.
.. versionadded:: 2.4
"""
f.evalcontextfunction = True
return f
def environmentfunction(f):
"""This decorator can be used to mark a function or method as environment
callable. This decorator works exactly like the :func:`contextfunction`
decorator just that the first argument is the active :class:`Environment`
and not context.
"""
f.environmentfunction = True
return f
def internalcode(f):
"""Marks the function as internally used"""
internal_code.add(f.__code__)
return f
def is_undefined(obj):
"""Check if the object passed is undefined. This does nothing more than
performing an instance check against :class:`Undefined` but looks nicer.
This can be used for custom filters or tests that want to react to
undefined variables. For example a custom default filter can look like
this::
def default(var, default=''):
if is_undefined(var):
return default
return var
"""
from jinja2.runtime import Undefined
return isinstance(obj, Undefined)
def consume(iterable):
"""Consumes an iterable without doing anything with it."""
for event in iterable:
pass
def clear_caches():
"""Jinja2 keeps internal caches for environments and lexers. These are
used so that Jinja2 doesn't have to recreate environments and lexers all
the time. Normally you don't have to care about that but if you are
measuring memory consumption you may want to clean the caches.
"""
from jinja2.environment import _spontaneous_environments
from jinja2.lexer import _lexer_cache
_spontaneous_environments.clear()
_lexer_cache.clear()
def import_string(import_name, silent=False):
"""Imports an object based on a string. This is useful if you want to
use import paths as endpoints or something similar. An import path can
be specified either in dotted notation (``xml.sax.saxutils.escape``)
or with a colon as object delimiter (``xml.sax.saxutils:escape``).
If the `silent` is True the return value will be `None` if the import
fails.
:return: imported object
"""
try:
if ':' in import_name:
module, obj = import_name.split(':', 1)
elif '.' in import_name:
items = import_name.split('.')
module = '.'.join(items[:-1])
obj = items[-1]
else:
return __import__(import_name)
return getattr(__import__(module, None, None, [obj]), obj)
except (ImportError, AttributeError):
if not silent:
raise
def open_if_exists(filename, mode='rb'):
"""Returns a file descriptor for the filename if that file exists,
otherwise `None`.
"""
try:
return open(filename, mode)
except IOError as e:
if e.errno not in (errno.ENOENT, errno.EISDIR, errno.EINVAL):
raise
def object_type_repr(obj):
"""Returns the name of the object's type. For some recognized
singletons the name of the object is returned instead. (For
example for `None` and `Ellipsis`).
"""
if obj is None:
return 'None'
elif obj is Ellipsis:
return 'Ellipsis'
# __builtin__ in 2.x, builtins in 3.x
if obj.__class__.__module__ in ('__builtin__', 'builtins'):
name = obj.__class__.__name__
else:
name = obj.__class__.__module__ + '.' + obj.__class__.__name__
return '%s object' % name
def pformat(obj, verbose=False):
"""Prettyprint an object. Either use the `pretty` library or the
builtin `pprint`.
"""
try:
from pretty import pretty
return pretty(obj, verbose=verbose)
except ImportError:
from pprint import pformat
return pformat(obj)
def urlize(text, trim_url_limit=None, rel=None, target=None):
"""Converts any URLs in text into clickable links. Works on http://,
https:// and www. links. Links can have trailing punctuation (periods,
commas, close-parens) and leading punctuation (opening parens) and
it'll still do the right thing.
If trim_url_limit is not None, the URLs in link text will be limited
to trim_url_limit characters.
If nofollow is True, the URLs in link text will get a rel="nofollow"
attribute.
If target is not None, a target attribute will be added to the link.
"""
trim_url = lambda x, limit=trim_url_limit: limit is not None \
and (x[:limit] + (len(x) >=limit and '...'
or '')) or x
words = re.split(r"(\s+)", text_type(escape(text)))
rel_attr = rel and ' rel="%s"' % text_type(escape(rel)) or ''
target_attr = target and ' target="%s"' % escape(target) or ''
for i, word in enumerate(words):
head, middle, tail = "", word, ""
match = re.match(r"^([(<]|<)+", middle)
if match:
head = match.group()
middle = middle[match.end() :]
# Unlike lead, which is anchored to the start of the string,
# need to check that the string ends with any of the characters
# before trying to match all of them, to avoid backtracking.
if middle.endswith((")", ">", ".", ",", "\n", ">")):
match = re.search(r"([)>.,\n]|>)+$", middle)
if match:
tail = match.group()
middle = middle[: match.start()]
if middle.startswith("www.") or (
"@" not in middle
and not middle.startswith("http://")
and not middle.startswith("https://")
and len(middle) > 0
and middle[0] in _letters + _digits
and (
middle.endswith(".org")
or middle.endswith(".net")
or middle.endswith(".com")
)
):
middle = '<a href="http://%s"%s%s>%s</a>' % (
middle,
rel_attr,
target_attr,
trim_url(middle),
)
if middle.startswith("http://") or middle.startswith("https://"):
middle = '<a href="%s"%s%s>%s</a>' % (
middle,
rel_attr,
target_attr,
trim_url(middle),
)
if (
"@" in middle
and not middle.startswith("www.")
and ":" not in middle
and re.match(r"^\S+@\w[\w.-]*\.\w+$", middle)
):
middle = '<a href="mailto:%s">%s</a>' % (middle, middle)
words[i] = head + middle + tail
return u''.join(words)
def generate_lorem_ipsum(n=5, html=True, min=20, max=100):
"""Generate some lorem ipsum for the template."""
from jinja2.constants import LOREM_IPSUM_WORDS
from random import choice, randrange
words = LOREM_IPSUM_WORDS.split()
result = []
for _ in range(n):
next_capitalized = True
last_comma = last_fullstop = 0
word = None
last = None
p = []
# each paragraph contains out of 20 to 100 words.
for idx, _ in enumerate(range(randrange(min, max))):
while True:
word = choice(words)
if word != last:
last = word
break
if next_capitalized:
word = word.capitalize()
next_capitalized = False
# add commas
if idx - randrange(3, 8) > last_comma:
last_comma = idx
last_fullstop += 2
word += ','
# add end of sentences
if idx - randrange(10, 20) > last_fullstop:
last_comma = last_fullstop = idx
word += '.'
next_capitalized = True
p.append(word)
# ensure that the paragraph ends with a dot.
p = u' '.join(p)
if p.endswith(','):
p = p[:-1] + '.'
elif not p.endswith('.'):
p += '.'
result.append(p)
if not html:
return u'\n\n'.join(result)
return Markup(u'\n'.join(u'<p>%s</p>' % escape(x) for x in result))
def unicode_urlencode(obj, charset='utf-8', for_qs=False):
"""URL escapes a single bytestring or unicode string with the
given charset if applicable to URL safe quoting under all rules
that need to be considered under all supported Python versions.
If non strings are provided they are converted to their unicode
representation first.
"""
if not isinstance(obj, string_types):
obj = text_type(obj)
if isinstance(obj, text_type):
obj = obj.encode(charset)
safe = not for_qs and b'/' or b''
rv = text_type(url_quote(obj, safe))
if for_qs:
rv = rv.replace('%20', '+')
return rv
class LRUCache(object):
"""A simple LRU Cache implementation."""
# this is fast for small capacities (something below 1000) but doesn't
# scale. But as long as it's only used as storage for templates this
# won't do any harm.
def __init__(self, capacity):
self.capacity = capacity
self._mapping = {}
self._queue = deque()
self._postinit()
def _postinit(self):
# alias all queue methods for faster lookup
self._popleft = self._queue.popleft
self._pop = self._queue.pop
self._remove = self._queue.remove
self._wlock = Lock()
self._append = self._queue.append
def __getstate__(self):
return {
'capacity': self.capacity,
'_mapping': self._mapping,
'_queue': self._queue
}
def __setstate__(self, d):
self.__dict__.update(d)
self._postinit()
def __getnewargs__(self):
return (self.capacity,)
def copy(self):
"""Return a shallow copy of the instance."""
rv = self.__class__(self.capacity)
rv._mapping.update(self._mapping)
rv._queue = deque(self._queue)
return rv
def get(self, key, default=None):
"""Return an item from the cache dict or `default`"""
try:
return self[key]
except KeyError:
return default
def setdefault(self, key, default=None):
"""Set `default` if the key is not in the cache otherwise
leave unchanged. Return the value of this key.
"""
self._wlock.acquire()
try:
try:
return self[key]
except KeyError:
self[key] = default
return default
finally:
self._wlock.release()
def clear(self):
"""Clear the cache."""
self._wlock.acquire()
try:
self._mapping.clear()
self._queue.clear()
finally:
self._wlock.release()
def __contains__(self, key):
"""Check if a key exists in this cache."""
return key in self._mapping
def __len__(self):
"""Return the current size of the cache."""
return len(self._mapping)
def __repr__(self):
return '<%s %r>' % (
self.__class__.__name__,
self._mapping
)
def __getitem__(self, key):
"""Get an item from the cache. Moves the item up so that it has the
highest priority then.
Raise a `KeyError` if it does not exist.
"""
self._wlock.acquire()
try:
rv = self._mapping[key]
if self._queue[-1] != key:
try:
self._remove(key)
except ValueError:
# if something removed the key from the container
# when we read, ignore the ValueError that we would
# get otherwise.
pass
self._append(key)
return rv
finally:
self._wlock.release()
def __setitem__(self, key, value):
"""Sets the value for an item. Moves the item up so that it
has the highest priority then.
"""
self._wlock.acquire()
try:
if key in self._mapping:
self._remove(key)
elif len(self._mapping) == self.capacity:
del self._mapping[self._popleft()]
self._append(key)
self._mapping[key] = value
finally:
self._wlock.release()
def __delitem__(self, key):
"""Remove an item from the cache dict.
Raise a `KeyError` if it does not exist.
"""
self._wlock.acquire()
try:
del self._mapping[key]
try:
self._remove(key)
except ValueError:
# __getitem__ is not locked, it might happen
pass
finally:
self._wlock.release()
def items(self):
"""Return a list of items."""
result = [(key, self._mapping[key]) for key in list(self._queue)]
result.reverse()
return result
def iteritems(self):
"""Iterate over all items."""
return iter(self.items())
def values(self):
"""Return a list of all values."""
return [x[1] for x in self.items()]
def itervalue(self):
"""Iterate over all values."""
return iter(self.values())
def keys(self):
"""Return a list of all keys ordered by most recent usage."""
return list(self)
def iterkeys(self):
"""Iterate over all keys in the cache dict, ordered by
the most recent usage.
"""
return reversed(tuple(self._queue))
__iter__ = iterkeys
def __reversed__(self):
"""Iterate over the values in the cache dict, oldest items
coming first.
"""
return iter(tuple(self._queue))
__copy__ = copy
# register the LRU cache as mutable mapping if possible
try:
from collections.abc import MutableMapping
MutableMapping.register(LRUCache)
except ImportError:
try:
from collections import MutableMapping
MutableMapping.register(LRUCache)
except ImportError:
pass
def select_autoescape(enabled_extensions=('html', 'htm', 'xml'),
disabled_extensions=(),
default_for_string=True,
default=False):
"""Intelligently sets the initial value of autoescaping based on the
filename of the template. This is the recommended way to configure
autoescaping if you do not want to write a custom function yourself.
If you want to enable it for all templates created from strings or
for all templates with `.html` and `.xml` extensions::
from jinja2 import Environment, select_autoescape
env = Environment(autoescape=select_autoescape(
enabled_extensions=('html', 'xml'),
default_for_string=True,
))
Example configuration to turn it on at all times except if the template
ends with `.txt`::
from jinja2 import Environment, select_autoescape
env = Environment(autoescape=select_autoescape(
disabled_extensions=('txt',),
default_for_string=True,
default=True,
))
The `enabled_extensions` is an iterable of all the extensions that
autoescaping should be enabled for. Likewise `disabled_extensions` is
a list of all templates it should be disabled for. If a template is
loaded from a string then the default from `default_for_string` is used.
If nothing matches then the initial value of autoescaping is set to the
value of `default`.
For security reasons this function operates case insensitive.
.. versionadded:: 2.9
"""
enabled_patterns = tuple('.' + x.lstrip('.').lower()
for x in enabled_extensions)
disabled_patterns = tuple('.' + x.lstrip('.').lower()
for x in disabled_extensions)
def autoescape(template_name):
if template_name is None:
return default_for_string
template_name = template_name.lower()
if template_name.endswith(enabled_patterns):
return True
if template_name.endswith(disabled_patterns):
return False
return default
return autoescape
def htmlsafe_json_dumps(obj, dumper=None, **kwargs):
"""Works exactly like :func:`dumps` but is safe for use in ``<script>``
tags. It accepts the same arguments and returns a JSON string. Note that
this is available in templates through the ``|tojson`` filter which will
also mark the result as safe. Due to how this function escapes certain
characters this is safe even if used outside of ``<script>`` tags.
The following characters are escaped in strings:
- ``<``
- ``>``
- ``&``
- ``'``
This makes it safe to embed such strings in any place in HTML with the
notable exception of double quoted attributes. In that case single
quote your attributes or HTML escape it in addition.
"""
if dumper is None:
dumper = json.dumps
rv = dumper(obj, **kwargs) \
.replace(u'<', u'\\u003c') \
.replace(u'>', u'\\u003e') \
.replace(u'&', u'\\u0026') \
.replace(u"'", u'\\u0027')
return Markup(rv)
@implements_iterator
class Cycler(object):
"""A cycle helper for templates."""
def __init__(self, *items):
if not items:
raise RuntimeError('at least one item has to be provided')
self.items = items
self.reset()
def reset(self):
"""Resets the cycle."""
self.pos = 0
@property
def current(self):
"""Returns the current item."""
return self.items[self.pos]
def next(self):
"""Goes one item ahead and returns it."""
rv = self.current
self.pos = (self.pos + 1) % len(self.items)
return rv
__next__ = next
class Joiner(object):
"""A joining helper for templates."""
def __init__(self, sep=u', '):
self.sep = sep
self.used = False
def __call__(self):
if not self.used:
self.used = True
return u''
return self.sep
class Namespace(object):
"""A namespace object that can hold arbitrary attributes. It may be
initialized from a dictionary or with keyword argments."""
def __init__(*args, **kwargs):
self, args = args[0], args[1:]
self.__attrs = dict(*args, **kwargs)
def __getattribute__(self, name):
if name == '_Namespace__attrs':
return object.__getattribute__(self, name)
try:
return self.__attrs[name]
except KeyError:
raise AttributeError(name)
def __setitem__(self, name, value):
self.__attrs[name] = value
def __repr__(self):
return '<Namespace %r>' % self.__attrs
# does this python version support async for in and async generators?
try:
exec('async def _():\n async for _ in ():\n yield _')
have_async_gen = True
except SyntaxError:
have_async_gen = False
# Imported here because that's where it was in the past
from markupsafe import Markup, escape, soft_unicode
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