Utility functions.
- :copyright: 2008 by Armin Ronacher.
+ :copyright: (c) 2010 by the Jinja Team.
:license: BSD, see LICENSE for more details.
"""
+import re
+import sys
+import errno
+try:
+ from thread import allocate_lock
+except ImportError:
+ from dummy_thread import allocate_lock
+from collections import deque
+from itertools import imap
-def escape(obj, attribute=False):
- """HTML escape an object."""
- if hasattr(obj, '__html__'):
- return obj.__html__()
- return unicode(obj) \
- .replace('&', '&') \
- .replace('>', '>') \
- .replace('<', '<') \
- .replace('"', '"')
+_word_split_re = re.compile(r'(\s+)')
+_punctuation_re = re.compile(
+ '^(?P<lead>(?:%s)*)(?P<middle>.*?)(?P<trail>(?:%s)*)$' % (
+ '|'.join(imap(re.escape, ('(', '<', '<'))),
+ '|'.join(imap(re.escape, ('.', ',', ')', '>', '\n', '>')))
+ )
+)
+_simple_email_re = re.compile(r'^\S+@[a-zA-Z0-9._-]+\.[a-zA-Z0-9._-]+$')
+_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'})()
-def pformat(obj, verbose=False):
+# internal code
+internal_code = set()
+
+
+# concatenate a list of strings and convert them to unicode.
+# unfortunately there is a bug in python 2.4 and lower that causes
+# unicode.join trash the traceback.
+_concat = u''.join
+try:
+ def _test_gen_bug():
+ raise TypeError(_test_gen_bug)
+ yield None
+ _concat(_test_gen_bug())
+except TypeError, _error:
+ if not _error.args or _error.args[0] is not _test_gen_bug:
+ def concat(gen):
+ try:
+ return _concat(list(gen))
+ except Exception:
+ # this hack is needed so that the current frame
+ # does not show up in the traceback.
+ exc_type, exc_value, tb = sys.exc_info()
+ raise exc_type, exc_value, tb.tb_next
+ else:
+ concat = _concat
+ del _test_gen_bug, _error
+
+
+# for python 2.x we create outselves a next() function that does the
+# basics without exception catching.
+try:
+ next = next
+except NameError:
+ def next(x):
+ return x.next()
+
+
+# if this python version is unable to deal with unicode filenames
+# when passed to encode we let this function encode it properly.
+# This is used in a couple of places. As far as Jinja is concerned
+# filenames are unicode *or* bytestrings in 2.x and unicode only in
+# 3.x because compile cannot handle bytes
+if sys.version_info < (3, 0):
+ def _encode_filename(filename):
+ if isinstance(filename, unicode):
+ return filename.encode('utf-8')
+ return filename
+else:
+ def _encode_filename(filename):
+ assert filename is None or isinstance(filename, str), \
+ 'filenames must be strings'
+ return filename
+
+from keyword import iskeyword as is_python_keyword
+
+
+# common types. These do exist in the special types module too which however
+# does not exist in IronPython out of the box. Also that way we don't have
+# to deal with implementation specific stuff here
+class _C(object):
+ def method(self): pass
+def _func():
+ yield None
+FunctionType = type(_func)
+GeneratorType = type(_func())
+MethodType = type(_C.method)
+CodeType = type(_C.method.func_code)
+try:
+ raise TypeError()
+except TypeError:
+ _tb = sys.exc_info()[2]
+ TracebackType = type(_tb)
+ FrameType = type(_tb.tb_frame)
+del _C, _tb, _func
+
+
+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 decoraotr 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.func_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
"""
- Prettyprint an object. Either use the `pretty` library or the
+ 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
+ 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()
+
+
+def import_string(import_name, silent=False):
+ """Imports an object based on a string. This use 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, e:
+ if e.errno not in (errno.ENOENT, errno.EISDIR):
+ 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:
except ImportError:
from pprint import pformat
return pformat(obj)
+
+
+def urlize(text, trim_url_limit=None, nofollow=False):
+ """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.
+ """
+ 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(unicode(escape(text)))
+ nofollow_attr = nofollow and ' rel="nofollow"' 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
+ 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</a>' % (middle,
+ nofollow_attr, trim_url(middle))
+ if middle.startswith('http://') or \
+ middle.startswith('https://'):
+ middle = '<a href="%s"%s>%s</a>' % (middle,
+ nofollow_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 impsum for the template."""
+ from jinja2.constants import LOREM_IPSUM_WORDS
+ from random import choice, randrange
+ words = LOREM_IPSUM_WORDS.split()
+ result = []
+
+ for _ in xrange(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(xrange(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))
+
+
+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
+ if hasattr(self._queue, 'remove'):
+ self._remove = self._queue.remove
+ self._wlock = allocate_lock()
+ self._append = self._queue.append
+
+ def _remove(self, obj):
+ """Python 2.4 compatibility."""
+ for idx, item in enumerate(self._queue):
+ if item == obj:
+ del self._queue[idx]
+ break
+
+ 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 an 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.
+ """
+ try:
+ return self[key]
+ except KeyError:
+ self[key] = default
+ return default
+
+ 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 an `KeyError` if it does not exist.
+ """
+ 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
+
+ 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:
+ try:
+ self._remove(key)
+ except ValueError:
+ # __getitem__ is not locked, it might happen
+ pass
+ 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 an `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 import MutableMapping
+ MutableMapping.register(LRUCache)
+except ImportError:
+ pass
+
+
+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
+
+
+# try markupsafe first, if that fails go with Jinja2's bundled version
+# of markupsafe. Markupsafe was previously Jinja2's implementation of
+# the Markup object but was moved into a separate package in a patchleve
+# release
+try:
+ from markupsafe import Markup, escape, soft_unicode
+except ImportError:
+ from jinja2._markupsafe import Markup, escape, soft_unicode
+
+
+# partials
+try:
+ from functools import partial
+except ImportError:
+ class partial(object):
+ def __init__(self, _func, *args, **kwargs):
+ self._func = _func
+ self._args = args
+ self._kwargs = kwargs
+ def __call__(self, *args, **kwargs):
+ kwargs.update(self._kwargs)
+ return self._func(*(self._args + args), **kwargs)
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