# -*- 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
from collections import deque
from threading import Lock
from jinja2._compat import text_type, string_types, implements_iterator, \
url_quote, abc
_word_split_re = re.compile(r'(\s+)')
_punctuation_re = re.compile(
'^(?P<lead>(?:%s)*)(?P<middle>.*?)(?P<trail>(?:%s)*)$' % (
'|'.join(map(re.escape, ('(', '<', '<'))),
'|'.join(map(re.escape, ('.', ',', ')', '>', '\n', '>')))
)
)
_simple_email_re = re.compile(r'^\S+@[a-zA-Z0-9._-]+\.[a-zA-Z0-9._-]+$')
_striptags_re = re.compile(r'(<!--.*?-->|<[^>]*>)')
_entity_re = re.compile(r'&([^;]+);')
_letters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
_digits = '0123456789'
# 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 = _word_split_re.split(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):
match = _punctuation_re.match(word)
if match:
lead, middle, trail = match.groups()
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 _simple_email_re.match(middle):
middle = '<a href="mailto:%s">%s</a>' % (middle, middle)
if lead + middle + trail != word:
words[i] = lead + middle + trail
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)
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