third_party/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 from jinja2._compat import text_type, string_types, mapping_types
  14
  15
  16 number_re = re.compile(r'^-?\d+(\.\d+)?$')
  17 regex_type = type(number_re)
  18
  19
  20 test_callable = callable
  21
  22
  23 def test_odd(value):
  24     """Return true if the variable is odd."""
  25     return value % 2 == 1
  26
  27
  28 def test_even(value):
  29     """Return true if the variable is even."""
  30     return value % 2 == 0
  31
  32
  33 def test_divisibleby(value, num):
  34     """Check if a variable is divisible by a number."""
  35     return value % num == 0
  36
  37
  38 def test_defined(value):
  39     """Return true if the variable is defined:
  40
  41     .. sourcecode:: jinja
  42
  43         {% if variable is defined %}
  44             value of variable: {{ variable }}
  45         {% else %}
  46             variable is not defined
  47         {% endif %}
  48
  49     See the :func:`default` filter for a simple way to set undefined
  50     variables.
  51     """
  52     return not isinstance(value, Undefined)
  53
  54
  55 def test_undefined(value):
  56     """Like :func:`defined` but the other way round."""
  57     return isinstance(value, Undefined)
  58
  59
  60 def test_none(value):
  61     """Return true if the variable is none."""
  62     return value is None
  63
  64
  65 def test_lower(value):
  66     """Return true if the variable is lowercased."""
  67     return text_type(value).islower()
  68
  69
  70 def test_upper(value):
  71     """Return true if the variable is uppercased."""
  72     return text_type(value).isupper()
  73
  74
  75 def test_string(value):
  76     """Return true if the object is a string."""
  77     return isinstance(value, string_types)
  78
  79
  80 def test_mapping(value):
  81     """Return true if the object is a mapping (dict etc.).
  82
  83     .. versionadded:: 2.6
  84     """
  85     return isinstance(value, mapping_types)
  86
  87
  88 def test_number(value):
  89     """Return true if the variable is a number."""
  90     return isinstance(value, (int, float, complex))
  91
  92
  93 def test_sequence(value):
  94     """Return true if the variable is a sequence. Sequences are variables
  95     that are iterable.
  96     """
  97     try:
  98         len(value)
  99         value.__getitem__
 100     except:
 101         return False
 102     return True
 103
 104
 105 def test_sameas(value, other):
 106     """Check if an object points to the same memory address than another
 107     object:
 108
 109     .. sourcecode:: jinja
 110
 111         {% if foo.attribute is sameas false %}
 112             the foo attribute really is the `False` singleton
 113         {% endif %}
 114     """
 115     return value is other
 116
 117
 118 def test_iterable(value):
 119     """Check if it's possible to iterate over an object."""
 120     try:
 121         iter(value)
 122     except TypeError:
 123         return False
 124     return True
 125
 126
 127 def test_escaped(value):
 128     """Check if the value is escaped."""
 129     return hasattr(value, '__html__')
 130
 131
 132 TESTS = {
 133     'odd':              test_odd,
 134     'even':             test_even,
 135     'divisibleby':      test_divisibleby,
 136     'defined':          test_defined,
 137     'undefined':        test_undefined,
 138     'none':             test_none,
 139     'lower':            test_lower,
 140     'upper':            test_upper,
 141     'string':           test_string,
 142     'mapping':          test_mapping,
 143     'number':           test_number,
 144     'sequence':         test_sequence,
 145     'iterable':         test_iterable,
 146     'callable':         test_callable,
 147     'sameas':           test_sameas,
 148     'escaped':          test_escaped
 149 }