validators.py

   1 from django.core.exceptions import ValidationError
   2 from django.utils.translation import ugettext_lazy as _
   3 from django.core.validators import RegexValidator
   4 import re
   5
   6
   7 class TreeParentValidator(object):
   8         """
   9         constructor takes instance and parent_attr, where instance is the model
  10         being validated and parent_attr is where to look on that parent for the
  11         comparison.
  12         """
  13         #message = _("A tree element can't be its own parent.")
  14         code = 'invalid'
  15
  16         def __init__(self, instance, parent_attr=None, message=None, code=None):
  17                 self.instance = instance
  18                 self.parent_attr = parent_attr
  19                 self.static_message = message
  20                 if code is not None:
  21                         self.code = code
  22
  23         def __call__(self, value):
  24                 """
  25                 Validates that the self.instance is not found in the parent tree of
  26                 the node given as value.
  27                 """
  28                 parent = value
  29
  30                 while parent:
  31                         comparison=self.get_comparison(parent)
  32                         if comparison == self.instance:
  33                                 # using (self.message, code=self.code) results in the admin interface
  34                                 # screwing with the error message and making it be 'Enter a valid value'
  35                                 raise ValidationError(self.message)
  36                         parent=parent.parent
  37
  38         def get_comparison(self, parent):
  39                 if self.parent_attr and hasattr(parent, self.parent_attr):
  40                         return getattr(parent, self.parent_attr)
  41
  42                 return parent
  43
  44         def get_message(self):
  45                 return self.static_message or _(u"A %s can't be its own parent." % self.instance.__class__.__name__)
  46         message = property(get_message)
  47
  48
  49 class TreePositionValidator(object):
  50         code = 'invalid'
  51
  52         def __init__(self, parent, slug, obj_class, message=None, code=None):
  53                 self.parent = parent
  54                 self.slug = slug
  55                 self.obj_class = obj_class
  56                 self.static_message = message
  57
  58                 if code is not None:
  59                         self.code = code
  60
  61         def __call__(self, value):
  62                 """
  63                 Validates that there is no obj of obj_class with the same position
  64                 as the compared obj (value) but a different id.
  65                 """
  66                 if not isinstance(value, self.obj_class):
  67                         raise ValidationError(_(u"The value must be an instance of %s." % self.obj_class.__name__))
  68
  69                 try:
  70                         obj = self.obj_class.objects.get(slug=self.slug, parent=self.parent)
  71
  72                         if obj.id != value.id:
  73                                 raise ValidationError(self.message)
  74
  75                 except self.obj_class.DoesNotExist:
  76                         pass
  77
  78         def get_message(self):
  79                 return self.static_message or _(u"A %s with that path (parent and slug) already exists." % self.obj_class.__name__)
  80         message = property(get_message)
  81
  82
  83 class RedirectValidator(RegexValidator):
  84         """Based loosely on the URLValidator, but no option to verify_exists"""
  85         regex = re.compile(
  86                 r'^(?:https?://' # http:// or https://
  87                 r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+[A-Z]{2,6}\.?|' #domain...
  88                 r'localhost|' #localhost...
  89                 r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})' # ...or ip
  90                 r'(?::\d+)?' # optional port
  91                 r'(?:/?|[/?#]?\S+)|'
  92                 r'[^?#\s]\S*)$',
  93                 re.IGNORECASE)
  94         message = _(u'Enter a valid absolute or relative redirect target')
  95
  96
  97 class URLLinkValidator(RegexValidator):
  98         """Based loosely on the URLValidator, but no option to verify_exists"""
  99         regex = re.compile(
 100                 r'^(?:https?://' # http:// or https://
 101                 r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+[A-Z]{2,6}\.?|' #domain...
 102                 r'localhost|' #localhost...
 103                 r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})' # ...or ip
 104                 r'(?::\d+)?' # optional port
 105                 r'|)' # also allow internal links
 106                 r'(?:/?|[/?#]?\S+)$', re.IGNORECASE)
 107         message = _(u'Enter a valid absolute or relative redirect target')