# -*- 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(?:%s)*)(?P.*?)(?P(?:%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 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 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 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): 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, 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(text_type(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 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 = '%s' % (middle, nofollow_attr, trim_url(middle)) if middle.startswith('http://') or \ middle.startswith('https://'): middle = '%s' % (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 = '%s' % (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 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'

%s

' % escape(x) for x in result)) def unicode_urlencode(obj, charset='utf-8'): """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) return text_type(url_quote(obj)) 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 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