# -*- coding: utf-8 -*-
"""
jinja2.utils
~~~~~~~~~~~~
Utility functions.
:copyright: (c) 2010 by the Jinja Team.
:license: BSD, see LICENSE for more details.
"""
import re
import errno
from collections import deque
from threading import Lock
from jinja2._compat import text_type, string_types, implements_iterator, \
url_quote
_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
[docs]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
[docs]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
[docs]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
[docs]def internalcode(f):
"""Marks the function as internally used"""
internal_code.add(f.__code__)
return f
[docs]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)
[docs]def consume(iterable):
"""Consumes an iterable without doing anything with it."""
for event in iterable:
pass
[docs]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
messuring 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()
[docs]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
[docs]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
[docs]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, nofollow=False, 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)))
nofollow_attr = nofollow and ' rel="nofollow"' or ''
if target is not None and isinstance(target, string_types):
target_attr = ' target="%s"' % target
else:
target_attr = ''
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,
nofollow_attr, target_attr, trim_url(middle))
if middle.startswith('http://') or \
middle.startswith('https://'):
middle = '<a href="%s"%s%s>%s</a>' % (middle,
nofollow_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 = for_qs and b'' or b'/'
rv = text_type(url_quote(obj, safe))
if for_qs:
rv = rv.replace('%20', '+')
return rv
[docs]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.
[docs] 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,)
[docs] 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
[docs] def get(self, key, default=None):
"""Return an item from the cache dict or `default`"""
try:
return self[key]
except KeyError:
return default
[docs] 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()
[docs] 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()
[docs] def items(self):
"""Return a list of items."""
result = [(key, self._mapping[key]) for key in list(self._queue)]
result.reverse()
return result
[docs] def iteritems(self):
"""Iterate over all items."""
return iter(self.items())
[docs] def values(self):
"""Return a list of all values."""
return [x[1] for x in self.items()]
[docs] def itervalue(self):
"""Iterate over all values."""
return iter(self.values())
[docs] def keys(self):
"""Return a list of all keys ordered by most recent usage."""
return list(self)
[docs] 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 import MutableMapping
MutableMapping.register(LRUCache)
except ImportError:
pass
@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
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
# Imported here because that's where it was in the past
from markupsafe import Markup, escape, soft_unicode