Python django.utils.functional.lazy() Examples

def csrf(request):
    """
    Context processor that provides a CSRF token, or the string 'NOTPROVIDED' if
    it has not been provided by either a view decorator or the middleware
    """
    def _get_val():
        token = get_token(request)
        if token is None:
            # In order to be able to provide debugging info in the
            # case of misconfiguration, we use a sentinel value
            # instead of returning an empty dict.
            return 'NOTPROVIDED'
        else:
            return smart_text(token)
    _get_val = lazy(_get_val, six.text_type)

    return {'csrf_token': _get_val()} 

def csrf(request):
    """
    Context processor that provides a CSRF token, or the string 'NOTPROVIDED' if
    it has not been provided by either a view decorator or the middleware
    """
    def _get_val():
        token = get_token(request)
        if token is None:
            # In order to be able to provide debugging info in the
            # case of misconfiguration, we use a sentinel value
            # instead of returning an empty dict.
            return 'NOTPROVIDED'
        else:
            return smart_text(token)
    _get_val = lazy(_get_val, six.text_type)

    return {'csrf_token': _get_val() } 

def __init__(self, **kwargs):
        self.allow_blank = kwargs.pop('allow_blank', False)
        self.trim_whitespace = kwargs.pop('trim_whitespace', True)
        self.max_length = kwargs.pop('max_length', None)
        self.min_length = kwargs.pop('min_length', None)
        super(CharField, self).__init__(**kwargs)
        if self.max_length is not None:
            message = lazy(
                self.error_messages['max_length'].format,
                six.text_type)(max_length=self.max_length)
            self.validators.append(
                MaxLengthValidator(self.max_length, message=message))
        if self.min_length is not None:
            message = lazy(
                self.error_messages['min_length'].format,
                six.text_type)(min_length=self.min_length)
            self.validators.append(
                MinLengthValidator(self.min_length, message=message)) 

def __init__(self, **kwargs):
        self.max_value = kwargs.pop('max_value', None)
        self.min_value = kwargs.pop('min_value', None)
        super(IntegerField, self).__init__(**kwargs)
        if self.max_value is not None:
            message = lazy(
                self.error_messages['max_value'].format,
                six.text_type)(max_value=self.max_value)
            self.validators.append(
                MaxValueValidator(self.max_value, message=message))
        if self.min_value is not None:
            message = lazy(
                self.error_messages['min_value'].format,
                six.text_type)(min_value=self.min_value)
            self.validators.append(
                MinValueValidator(self.min_value, message=message)) 

def __init__(self, **kwargs):
        self.max_value = kwargs.pop('max_value', None)
        self.min_value = kwargs.pop('min_value', None)
        super(FloatField, self).__init__(**kwargs)
        if self.max_value is not None:
            message = lazy(
                self.error_messages['max_value'].format,
                six.text_type)(max_value=self.max_value)
            self.validators.append(
                MaxValueValidator(self.max_value, message=message))
        if self.min_value is not None:
            message = lazy(
                self.error_messages['min_value'].format,
                six.text_type)(min_value=self.min_value)
            self.validators.append(
                MinValueValidator(self.min_value, message=message)) 

def lazy_number(func, resultclass, number=None, **kwargs):
    if isinstance(number, six.integer_types):
        kwargs['number'] = number
        proxy = lazy(func, resultclass)(**kwargs)
    else:
        class NumberAwareString(resultclass):
            def __mod__(self, rhs):
                if isinstance(rhs, dict) and number:
                    try:
                        number_value = rhs[number]
                    except KeyError:
                        raise KeyError('Your dictionary lacks key \'%s\'. '
                            'Please provide it, because it is required to '
                            'determine whether string is singular or plural.'
                            % number)
                else:
                    number_value = rhs
                kwargs['number'] = number_value
                translated = func(**kwargs)
                try:
                    translated = translated % rhs
                except TypeError:
                    # String doesn't contain a placeholder for the number
                    pass
                return translated

        proxy = lazy(lambda **kwargs: NumberAwareString(), NumberAwareString)(**kwargs)
    return proxy 

def test_CharField(self):
        lazy_func = lazy(lambda: '', str)
        self.assertIsInstance(CharField().get_prep_value(lazy_func()), str)
        lazy_func = lazy(lambda: 0, int)
        self.assertIsInstance(CharField().get_prep_value(lazy_func()), str) 

def test_DateField(self):
        lazy_func = lazy(lambda: datetime.date.today(), datetime.date)
        self.assertIsInstance(DateField().get_prep_value(lazy_func()), datetime.date) 

def test_AutoField(self):
        lazy_func = lazy(lambda: 1, int)
        self.assertIsInstance(AutoField(primary_key=True).get_prep_value(lazy_func()), int) 

def test_lazy_strings_not_evaluated(self):
        lazy_func = lazy(lambda x: 0 / 0, int)  # raises ZeroDivisionError if evaluated.
        f = models.CharField(choices=[(lazy_func('group'), (('a', 'A'), ('b', 'B')))])
        self.assertEqual(f.get_choices(include_blank=True)[0], ('', '---------')) 

def test_lazy_repr_bytes(self):
        original_object = b'J\xc3\xbcst a str\xc3\xadng'
        lazy_obj = lazy(lambda: original_object, bytes)
        self.assertEqual(repr(original_object), repr(lazy_obj())) 

def test_lazy_repr_int(self):
        original_object = 15
        lazy_obj = lazy(lambda: original_object, int)
        self.assertEqual(repr(original_object), repr(lazy_obj())) 

def test_BooleanField(self):
        lazy_func = lazy(lambda: True, bool)
        self.assertIsInstance(BooleanField().get_prep_value(lazy_func()), bool) 

def test_URLField(self):
        lazy_func = lazy(lambda: 'http://domain.com', str)
        self.assertIsInstance(URLField().get_prep_value(lazy_func()), str) 

def test_TimeField(self):
        lazy_func = lazy(lambda: datetime.datetime.now().time(), datetime.time)
        self.assertIsInstance(TimeField().get_prep_value(lazy_func()), datetime.time) 

def test_TextField(self):
        lazy_func = lazy(lambda: 'Abc', str)
        self.assertIsInstance(TextField().get_prep_value(lazy_func()), str)
        lazy_func = lazy(lambda: 0, int)
        self.assertIsInstance(TextField().get_prep_value(lazy_func()), str) 

def test_SmallIntegerField(self):
        lazy_func = lazy(lambda: 1, int)
        self.assertIsInstance(SmallIntegerField().get_prep_value(lazy_func()), int) 

def test_SlugField(self):
        lazy_func = lazy(lambda: 'slug', str)
        self.assertIsInstance(SlugField().get_prep_value(lazy_func()), str)
        lazy_func = lazy(lambda: 0, int)
        self.assertIsInstance(SlugField().get_prep_value(lazy_func()), str) 

def test_PositiveIntegerField(self):
        lazy_func = lazy(lambda: 1, int)
        self.assertIsInstance(PositiveIntegerField().get_prep_value(lazy_func()), int) 

def test_NullBooleanField(self):
        lazy_func = lazy(lambda: True, bool)
        self.assertIsInstance(NullBooleanField().get_prep_value(lazy_func()), bool) 

def test_GenericIPAddressField(self):
        lazy_func = lazy(lambda: '127.0.0.1', str)
        self.assertIsInstance(GenericIPAddressField().get_prep_value(lazy_func()), str)
        lazy_func = lazy(lambda: 0, int)
        self.assertIsInstance(GenericIPAddressField().get_prep_value(lazy_func()), str) 

def test_IPAddressField(self):
        lazy_func = lazy(lambda: '127.0.0.1', str)
        self.assertIsInstance(IPAddressField().get_prep_value(lazy_func()), str)
        lazy_func = lazy(lambda: 0, int)
        self.assertIsInstance(IPAddressField().get_prep_value(lazy_func()), str) 

def test_IntegerField(self):
        lazy_func = lazy(lambda: 1, int)
        self.assertIsInstance(IntegerField().get_prep_value(lazy_func()), int) 

def test_FloatField(self):
        lazy_func = lazy(lambda: 1.2, float)
        self.assertIsInstance(FloatField().get_prep_value(lazy_func()), float) 

def test_FilePathField(self):
        lazy_func = lazy(lambda: 'tests.py', str)
        self.assertIsInstance(FilePathField().get_prep_value(lazy_func()), str)
        lazy_func = lazy(lambda: 0, int)
        self.assertIsInstance(FilePathField().get_prep_value(lazy_func()), str) 

def test_FileField(self):
        lazy_func = lazy(lambda: 'filename.ext', str)
        self.assertIsInstance(FileField().get_prep_value(lazy_func()), str)
        lazy_func = lazy(lambda: 0, int)
        self.assertIsInstance(FileField().get_prep_value(lazy_func()), str) 

def test_EmailField(self):
        lazy_func = lazy(lambda: 'mailbox@domain.com', str)
        self.assertIsInstance(EmailField().get_prep_value(lazy_func()), str) 

def test_DecimalField(self):
        lazy_func = lazy(lambda: Decimal('1.2'), Decimal)
        self.assertIsInstance(DecimalField().get_prep_value(lazy_func()), Decimal) 

def test_DateField(self):
        lazy_func = lazy(lambda: datetime.date.today(), datetime.date)
        self.assertIsInstance(DateField().get_prep_value(lazy_func()), datetime.date) 

def test_DecimalField(self):
        lazy_func = lazy(lambda: Decimal('1.2'), Decimal)
        self.assertIsInstance(DecimalField().get_prep_value(lazy_func()), Decimal)