python27/guestbook/jinja2/tests.py

   1 # -*- coding: utf-8 -*-
   2 """
   3     jinja2.tests
   4     ~~~~~~~~~~~~
   5
   6     Jinja test functions. Used with the "is" operator.
   7
   8     :copyright: (c) 2010 by the Jinja Team.
   9     :license: BSD, see LICENSE for more details.
  10 """
  11 import re
  12 from jinja2.runtime import Undefined
  13
  14 try:
  15     from collections import Mapping as MappingType
  16 except ImportError:
  17     import UserDict
  18     MappingType = (UserDict.UserDict, UserDict.DictMixin, dict)
  19
  20 # nose, nothing here to test
  21 __test__ = False
  22
  23
  24 number_re = re.compile(r'^-?\d+(\.\d+)?$')
  25 regex_type = type(number_re)
  26
  27
  28 try:
  29     test_callable = callable
  30 except NameError:
  31     def test_callable(x):
  32         return hasattr(x, '__call__')
  33
  34
  35 def test_odd(value):
  36     """Return true if the variable is odd."""
  37     return value % 2 == 1
  38
  39
  40 def test_even(value):
  41     """Return true if the variable is even."""
  42     return value % 2 == 0
  43
  44
  45 def test_divisibleby(value, num):
  46     """Check if a variable is divisible by a number."""
  47     return value % num == 0
  48
  49
  50 def test_defined(value):
  51     """Return true if the variable is defined:
  52
  53     .. sourcecode:: jinja
  54
  55         {% if variable is defined %}
  56             value of variable: {{ variable }}
  57         {% else %}
  58             variable is not defined
  59         {% endif %}
  60
  61     See the :func:`default` filter for a simple way to set undefined
  62     variables.
  63     """
  64     return not isinstance(value, Undefined)
  65
  66
  67 def test_undefined(value):
  68     """Like :func:`defined` but the other way round."""
  69     return isinstance(value, Undefined)
  70
  71
  72 def test_none(value):
  73     """Return true if the variable is none."""
  74     return value is None
  75
  76
  77 def test_lower(value):
  78     """Return true if the variable is lowercased."""
  79     return unicode(value).islower()
  80
  81
  82 def test_upper(value):
  83     """Return true if the variable is uppercased."""
  84     return unicode(value).isupper()
  85
  86
  87 def test_string(value):
  88     """Return true if the object is a string."""
  89     return isinstance(value, basestring)
  90
  91
  92 def test_mapping(value):
  93     """Return true if the object is a mapping (dict etc.).
  94
  95     .. versionadded:: 2.6
  96     """
  97     return isinstance(value, MappingType)
  98
  99
 100 def test_number(value):
 101     """Return true if the variable is a number."""
 102     return isinstance(value, (int, long, float, complex))
 103
 104
 105 def test_sequence(value):
 106     """Return true if the variable is a sequence. Sequences are variables
 107     that are iterable.
 108     """
 109     try:
 110         len(value)
 111         value.__getitem__
 112     except:
 113         return False
 114     return True
 115
 116
 117 def test_sameas(value, other):
 118     """Check if an object points to the same memory address than another
 119     object:
 120
 121     .. sourcecode:: jinja
 122
 123         {% if foo.attribute is sameas false %}
 124             the foo attribute really is the `False` singleton
 125         {% endif %}
 126     """
 127     return value is other
 128
 129
 130 def test_iterable(value):
 131     """Check if it's possible to iterate over an object."""
 132     try:
 133         iter(value)
 134     except TypeError:
 135         return False
 136     return True
 137
 138
 139 def test_escaped(value):
 140     """Check if the value is escaped."""
 141     return hasattr(value, '__html__')
 142
 143
 144 TESTS = {
 145     'odd':              test_odd,
 146     'even':             test_even,
 147     'divisibleby':      test_divisibleby,
 148     'defined':          test_defined,
 149     'undefined':        test_undefined,
 150     'none':             test_none,
 151     'lower':            test_lower,
 152     'upper':            test_upper,
 153     'string':           test_string,
 154     'mapping':          test_mapping,
 155     'number':           test_number,
 156     'sequence':         test_sequence,
 157     'iterable':         test_iterable,
 158     'callable':         test_callable,
 159     'sameas':           test_sameas,
 160     'escaped':          test_escaped
 161 }