# -*- coding: utf-8 -*-
"""
jinja2.filters
~~~~~~~~~~~~~~
Bundled jinja filters.
:copyright: (c) 2010 by the Jinja Team.
:license: BSD, see LICENSE for more details.
"""
import re
import math
from random import choice
from operator import itemgetter
from itertools import imap, groupby
from jinja2.utils import Markup, escape, pformat, urlize, soft_unicode
from jinja2.runtime import Undefined
from jinja2.exceptions import FilterArgumentError, SecurityError
_word_re = re.compile(r'\w+(?u)')
def contextfilter(f):
"""Decorator for marking context dependent filters. The current
:class:`Context` will be passed as first argument.
"""
if getattr(f, 'environmentfilter', False):
raise TypeError('filter already marked as environment filter')
f.contextfilter = True
return f
def environmentfilter(f):
"""Decorator for marking evironment dependent filters. The current
:class:`Environment` is passed to the filter as first argument.
"""
if getattr(f, 'contextfilter', False):
raise TypeError('filter already marked as context filter')
f.environmentfilter = True
return f
def do_forceescape(value):
"""Enforce HTML escaping. This will probably double escape variables."""
if hasattr(value, '__html__'):
value = value.__html__()
return escape(unicode(value))
@environmentfilter
def do_replace(environment, s, old, new, count=None):
"""Return a copy of the value with all occurrences of a substring
replaced with a new one. The first argument is the substring
that should be replaced, the second is the replacement string.
If the optional third argument ``count`` is given, only the first
``count`` occurrences are replaced:
.. sourcecode:: jinja
{{ "Hello World"|replace("Hello", "Goodbye") }}
-> Goodbye World
{{ "aaaaargh"|replace("a", "d'oh, ", 2) }}
-> d'oh, d'oh, aaargh
"""
if count is None:
count = -1
if not environment.autoescape:
return unicode(s).replace(unicode(old), unicode(new), count)
if hasattr(old, '__html__') or hasattr(new, '__html__') and \
not hasattr(s, '__html__'):
s = escape(s)
else:
s = soft_unicode(s)
return s.replace(soft_unicode(old), soft_unicode(new), count)
def do_upper(s):
"""Convert a value to uppercase."""
return soft_unicode(s).upper()
def do_lower(s):
"""Convert a value to lowercase."""
return soft_unicode(s).lower()
@environmentfilter
def do_xmlattr(_environment, d, autospace=True):
"""Create an SGML/XML attribute string based on the items in a dict.
All values that are neither `none` nor `undefined` are automatically
escaped:
.. sourcecode:: html+jinja
<ul{{ {'class': 'my_list', 'missing': none,
'id': 'list-%d'|format(variable)}|xmlattr }}>
...
</ul>
Results in something like this:
.. sourcecode:: html
<ul class="my_list" id="list-42">
...
</ul>
As you can see it automatically prepends a space in front of the item
if the filter returned something unless the second parameter is false.
"""
rv = u' '.join(
u'%s="%s"' % (escape(key), escape(value))
for key, value in d.iteritems()
if value is not None and not isinstance(value, Undefined)
)
if autospace and rv:
rv = u' ' + rv
if _environment.autoescape:
rv = Markup(rv)
return rv
def do_capitalize(s):
"""Capitalize a value. The first character will be uppercase, all others
lowercase.
"""
return soft_unicode(s).capitalize()
def do_title(s):
"""Return a titlecased version of the value. I.e. words will start with
uppercase letters, all remaining characters are lowercase.
"""
return soft_unicode(s).title()
def do_dictsort(value, case_sensitive=False, by='key'):
"""Sort a dict and yield (key, value) pairs. Because python dicts are
unsorted you may want to use this function to order them by either
key or value:
.. sourcecode:: jinja
{% for item in mydict|dictsort %}
sort the dict by key, case insensitive
{% for item in mydict|dicsort(true) %}
sort the dict by key, case sensitive
{% for item in mydict|dictsort(false, 'value') %}
sort the dict by key, case insensitive, sorted
normally and ordered by value.
"""
if by == 'key':
pos = 0
elif by == 'value':
pos = 1
else:
raise FilterArgumentError('You can only sort by either '
'"key" or "value"')
def sort_func(item):
value = item[pos]
if isinstance(value, basestring) and not case_sensitive:
value = value.lower()
return value
return sorted(value.items(), key=sort_func)
def do_sort(value, case_sensitive=False):
"""Sort an iterable. If the iterable is made of strings the second
parameter can be used to control the case sensitiveness of the
comparison which is disabled by default.
.. sourcecode:: jinja
{% for item in iterable|sort %}
...
{% endfor %}
"""
if not case_sensitive:
def sort_func(item):
if isinstance(item, basestring):
item = item.lower()
return item
else:
sort_func = None
return sorted(seq, key=sort_func)
def do_default(value, default_value=u'', boolean=False):
"""If the value is undefined it will return the passed default value,
otherwise the value of the variable:
.. sourcecode:: jinja
{{ my_variable|default('my_variable is not defined') }}
This will output the value of ``my_variable`` if the variable was
defined, otherwise ``'my_variable is not defined'``. If you want
to use default with variables that evaluate to false you have to
set the second parameter to `true`:
.. sourcecode:: jinja
{{ ''|default('the string was empty', true) }}
"""
if (boolean and not value) or isinstance(value, Undefined):
return default_value
return value
@environmentfilter
def do_join(environment, value, d=u''):
"""Return a string which is the concatenation of the strings in the
sequence. The separator between elements is an empty string per
default, you can define it with the optional parameter:
.. sourcecode:: jinja
{{ [1, 2, 3]|join('|') }}
-> 1|2|3
{{ [1, 2, 3]|join }}
-> 123
"""
# no automatic escaping? joining is a lot eaiser then
if not environment.autoescape:
return unicode(d).join(imap(unicode, value))
# if the delimiter doesn't have an html representation we check
# if any of the items has. If yes we do a coercion to Markup
if not hasattr(d, '__html__'):
value = list(value)
do_escape = False
for idx, item in enumerate(value):
if hasattr(item, '__html__'):
do_escape = True
else:
value[idx] = unicode(item)
if do_escape:
d = escape(d)
else:
d = unicode(d)
return d.join(value)
# no html involved, to normal joining
return soft_unicode(d).join(imap(soft_unicode, value))
def do_center(value, width=80):
"""Centers the value in a field of a given width."""
return unicode(value).center(width)
@environmentfilter
def do_first(environment, seq):
"""Return the first item of a sequence."""
try:
return iter(seq).next()
except StopIteration:
return environment.undefined('No first item, sequence was empty.')
@environmentfilter
def do_last(environment, seq):
"""Return the last item of a sequence."""
try:
return iter(reversed(seq)).next()
except StopIteration:
return environment.undefined('No last item, sequence was empty.')
@environmentfilter
def do_random(environment, seq):
"""Return a random item from the sequence."""
try:
return choice(seq)
except IndexError:
return environment.undefined('No random item, sequence was empty.')
def do_filesizeformat(value, binary=False):
"""Format the value like a 'human-readable' file size (i.e. 13 KB,
4.1 MB, 102 bytes, etc). Per default decimal prefixes are used (mega,
giga, etc.), if the second parameter is set to `True` the binary
prefixes are used (mebi, gibi).
"""
bytes = float(value)
base = binary and 1024 or 1000
middle = binary and 'i' or ''
if bytes < base:
return "%d Byte%s" % (bytes, bytes != 1 and 's' or '')
elif bytes < base * base:
return "%.1f K%sB" % (bytes / base, middle)
elif bytes < base * base * base:
return "%.1f M%sB" % (bytes / (base * base), middle)
return "%.1f G%sB" % (bytes / (base * base * base), middle)
def do_pprint(value, verbose=False):
"""Pretty print a variable. Useful for debugging.
With Jinja 1.2 onwards you can pass it a parameter. If this parameter
is truthy the output will be more verbose (this requires `pretty`)
"""
return pformat(value, verbose=verbose)
@environmentfilter
def do_urlize(environment, value, trim_url_limit=None, nofollow=False):
"""Converts URLs in plain text into clickable links.
If you pass the filter an additional integer it will shorten the urls
to that number. Also a third argument exists that makes the urls
"nofollow":
.. sourcecode:: jinja
{{ mytext|urlize(40, true) }}
links are shortened to 40 chars and defined with rel="nofollow"
"""
rv = urlize(value, trim_url_limit, nofollow)
if environment.autoescape:
rv = Markup(rv)
return rv
def do_indent(s, width=4, indentfirst=False):
"""Return a copy of the passed string, each line indented by
4 spaces. The first line is not indented. If you want to
change the number of spaces or indent the first line too
you can pass additional parameters to the filter:
.. sourcecode:: jinja
{{ mytext|indent(2, true) }}
indent by two spaces and indent the first line too.
"""
indention = u' ' * width
rv = (u'\n' + indention).join(s.splitlines())
if indentfirst:
rv = indention + rv
return rv
def do_truncate(s, length=255, killwords=False, end='...'):
"""Return a truncated copy of the string. The length is specified
with the first parameter which defaults to ``255``. If the second
parameter is ``true`` the filter will cut the text at length. Otherwise
it will try to save the last word. If the text was in fact
truncated it will append an ellipsis sign (``"..."``). If you want a
different ellipsis sign than ``"..."`` you can specify it using the
third parameter.
.. sourcecode jinja::
{{ mytext|truncate(300, false, '»') }}
truncate mytext to 300 chars, don't split up words, use a
right pointing double arrow as ellipsis sign.
"""
if len(s) <= length:
return s
elif killwords:
return s[:length] + end
words = s.split(' ')
result = []
m = 0
for word in words:
m += len(word) + 1
if m > length:
break
result.append(word)
result.append(end)
return u' '.join(result)
def do_wordwrap(s, width=79, break_long_words=True):
"""
Return a copy of the string passed to the filter wrapped after
``79`` characters. You can override this default using the first
parameter. If you set the second parameter to `false` Jinja will not
split words apart if they are longer than `width`.
"""
import textwrap
return u'\n'.join(textwrap.wrap(s, width=width, expand_tabs=False,
replace_whitespace=False,
break_long_words=break_long_words))
def do_wordcount(s):
"""Count the words in that string."""
return len(_word_re.findall(s))
def do_int(value, default=0):
"""Convert the value into an integer. If the
conversion doesn't work it will return ``0``. You can
override this default using the first parameter.
"""
try:
return int(value)
except (TypeError, ValueError):
# this quirk is necessary so that "42.23"|int gives 42.
try:
return int(float(value))
except (TypeError, ValueError):
return default
def do_float(value, default=0.0):
"""Convert the value into a floating point number. If the
conversion doesn't work it will return ``0.0``. You can
override this default using the first parameter.
"""
try:
return float(value)
except (TypeError, ValueError):
return default
def do_format(value, *args, **kwargs):
"""
Apply python string formatting on an object:
.. sourcecode:: jinja
{{ "%s - %s"|format("Hello?", "Foo!") }}
-> Hello? - Foo!
"""
if args and kwargs:
raise FilterArgumentError('can\'t handle positional and keyword '
'arguments at the same time')
return soft_unicode(value) % (kwargs or args)
def do_trim(value):
"""Strip leading and trailing whitespace."""
return soft_unicode(value).strip()
def do_striptags(value):
"""Strip SGML/XML tags and replace adjacent whitespace by one space.
"""
if hasattr(value, '__html__'):
value = value.__html__()
return Markup(unicode(value)).striptags()
def do_slice(value, slices, fill_with=None):
"""Slice an iterator and return a list of lists containing
those items. Useful if you want to create a div containing
three ul tags that represent columns:
.. sourcecode:: html+jinja
<div class="columwrapper">
{%- for column in items|slice(3) %}
<ul class="column-{{ loop.index }}">
{%- for item in column %}
<li>{{ item }}</li>
{%- endfor %}
</ul>
{%- endfor %}
</div>
If you pass it a second argument it's used to fill missing
values on the last iteration.
"""
seq = list(value)
length = len(seq)
items_per_slice = length // slices
slices_with_extra = length % slices
offset = 0
for slice_number in xrange(slices):
start = offset + slice_number * items_per_slice
if slice_number < slices_with_extra:
offset += 1
end = offset + (slice_number + 1) * items_per_slice
tmp = seq[start:end]
if fill_with is not None and slice_number >= slices_with_extra:
tmp.append(fill_with)
yield tmp
def do_batch(value, linecount, fill_with=None):
"""
A filter that batches items. It works pretty much like `slice`
just the other way round. It returns a list of lists with the
given number of items. If you provide a second parameter this
is used to fill missing items. See this example:
.. sourcecode:: html+jinja
<table>
{%- for row in items|batch(3, ' ') %}
<tr>
{%- for column in row %}
<td>{{ column }}</td>
{%- endfor %}
</tr>
{%- endfor %}
</table>
"""
result = []
tmp = []
for item in value:
if len(tmp) == linecount:
yield tmp
tmp = []
tmp.append(item)
if tmp:
if fill_with is not None and len(tmp) < linecount:
tmp += [fill_with] * (linecount - len(tmp))
yield tmp
def do_round(value, precision=0, method='common'):
"""Round the number to a given precision. The first
parameter specifies the precision (default is ``0``), the
second the rounding method:
- ``'common'`` rounds either up or down
- ``'ceil'`` always rounds up
- ``'floor'`` always rounds down
If you don't specify a method ``'common'`` is used.
.. sourcecode:: jinja
{{ 42.55|round }}
-> 43.0
{{ 42.55|round(1, 'floor') }}
-> 42.5
Note that even if rounded to 0 precision, a float is returned. If
you need a real integer, pipe it through `int`:
.. sourcecode:: jinja
{{ 42.55|round|int }}
-> 43
"""
if not method in ('common', 'ceil', 'floor'):
raise FilterArgumentError('method must be common, ceil or floor')
if precision < 0:
raise FilterArgumentError('precision must be a postive integer '
'or zero.')
if method == 'common':
return round(value, precision)
func = getattr(math, method)
if precision:
return func(value * 10 * precision) / (10 * precision)
else:
return func(value)
def do_sort(value, reverse=False):
"""Sort a sequence. Per default it sorts ascending, if you pass it
true as first argument it will reverse the sorting.
"""
return sorted(value, reverse=reverse)
@environmentfilter
def do_groupby(environment, value, attribute):
"""Group a sequence of objects by a common attribute.
If you for example have a list of dicts or objects that represent persons
with `gender`, `first_name` and `last_name` attributes and you want to
group all users by genders you can do something like the following
snippet:
.. sourcecode:: html+jinja
<ul>
{% for group in persons|groupby('gender') %}
<li>{{ group.grouper }}<ul>
{% for person in group.list %}
<li>{{ person.first_name }} {{ person.last_name }}</li>
{% endfor %}</ul></li>
{% endfor %}
</ul>
Additionally it's possible to use tuple unpacking for the grouper and
list:
.. sourcecode:: html+jinja
<ul>
{% for grouper, list in persons|groupby('gender') %}
...
{% endfor %}
</ul>
As you can see the item we're grouping by is stored in the `grouper`
attribute and the `list` contains all the objects that have this grouper
in common.
"""
expr = lambda x: environment.getitem(x, attribute)
return sorted(map(_GroupTuple, groupby(sorted(value, key=expr), expr)))
class _GroupTuple(tuple):
__slots__ = ()
grouper = property(itemgetter(0))
list = property(itemgetter(1))
def __new__(cls, (key, value)):
return tuple.__new__(cls, (key, list(value)))
def do_list(value):
"""Convert the value into a list. If it was a string the returned list
will be a list of characters.
"""
return list(value)
def do_mark_safe(value):
"""Mark the value as safe which means that in an environment with automatic
escaping enabled this variable will not be escaped.
"""
return Markup(value)
def do_mark_unsafe(value):
"""Mark a value as unsafe. This is the reverse operation for :func:`safe`."""
return unicode(value)
def do_reverse(value):
"""Reverse the object or return an iterator the iterates over it the other
way round.
"""
if isinstance(value, basestring):
return value[::-1]
try:
return reversed(value)
except TypeError:
try:
rv = list(value)
rv.reverse()
return rv
except TypeError:
raise FilterArgumentError('argument must be iterable')
@environmentfilter
def do_attr(environment, obj, name):
"""Get an attribute of an object. ``foo|attr("bar")`` works like
``foo["bar"]`` just that always an attribute is returned and items are not
looked up.
See :ref:`Notes on subscriptions <notes-on-subscriptions>` for more details.
"""
try:
name = str(name)
except UnicodeError:
pass
else:
try:
value = getattr(obj, name)
except AttributeError:
pass
else:
if environment.sandboxed and not \
environment.is_safe_attribute(obj, name, value):
return environment.unsafe_undefined(obj, name)
return value
return environment.undefined(obj=obj, name=name)
FILTERS = {
'attr': do_attr,
'replace': do_replace,
'upper': do_upper,
'lower': do_lower,
'escape': escape,
'e': escape,
'forceescape': do_forceescape,
'capitalize': do_capitalize,
'title': do_title,
'default': do_default,
'd': do_default,
'join': do_join,
'count': len,
'dictsort': do_dictsort,
'sort': do_sort,
'length': len,
'reverse': do_reverse,
'center': do_center,
'indent': do_indent,
'title': do_title,
'capitalize': do_capitalize,
'first': do_first,
'last': do_last,
'random': do_random,
'filesizeformat': do_filesizeformat,
'pprint': do_pprint,
'truncate': do_truncate,
'wordwrap': do_wordwrap,
'wordcount': do_wordcount,
'int': do_int,
'float': do_float,
'string': soft_unicode,
'list': do_list,
'urlize': do_urlize,
'format': do_format,
'trim': do_trim,
'striptags': do_striptags,
'slice': do_slice,
'batch': do_batch,
'sum': sum,
'abs': abs,
'round': do_round,
'sort': do_sort,
'groupby': do_groupby,
'safe': do_mark_safe,
'xmlattr': do_xmlattr
}