""" Serializer fields perform validation on incoming data. They are very similar to Django's form fields. """ from __future__ import unicode_literals import copy import datetime from decimal import Decimal, DecimalException import inspect import re import warnings from django.core import validators from django.core.exceptions import ValidationError from django.conf import settings from django import forms from django.forms import widgets from django.utils.encoding import is_protected_type from django.utils.translation import ugettext_lazy as _ from rest_framework import ISO_8601 from rest_framework.compat import timezone, parse_date, parse_datetime, parse_time from rest_framework.compat import BytesIO from rest_framework.compat import six from rest_framework.compat import smart_text from rest_framework.settings import api_settings def is_simple_callable(obj): """ True if the object is a callable that takes no arguments. """ function = inspect.isfunction(obj) method = inspect.ismethod(obj) if not (function or method): return False args, _, _, defaults = inspect.getargspec(obj) len_args = len(args) if function else len(args) - 1 len_defaults = len(defaults) if defaults else 0 return len_args <= len_defaults def get_component(obj, attr_name): """ Given an object, and an attribute name, return that attribute on the object. """ if isinstance(obj, dict): val = obj[attr_name] else: val = getattr(obj, attr_name) if is_simple_callable(val): return val() return val def readable_datetime_formats(formats): format = ', '.join(formats).replace(ISO_8601, 'YYYY-MM-DDThh:mm[:ss[.uuuuuu]][+HHMM|-HHMM|Z]') return humanize_strptime(format) def readable_date_formats(formats): format = ', '.join(formats).replace(ISO_8601, 'YYYY[-MM[-DD]]') return humanize_strptime(format) def readable_time_formats(formats): format = ', '.join(formats).replace(ISO_8601, 'hh:mm[:ss[.uuuuuu]]') return humanize_strptime(format) def humanize_strptime(format_string): # Note that we're missing some of the locale specific mappings that # don't really make sense. mapping = { "%Y": "YYYY", "%y": "YY", "%m": "MM", "%b": "[Jan-Dec]", "%B": "[January-December]", "%d": "DD", "%H": "hh", "%I": "hh", # Requires '%p' to differentiate from '%H'. "%M": "mm", "%S": "ss", "%f": "uuuuuu", "%a": "[Mon-Sun]", "%A": "[Monday-Sunday]", "%p": "[AM|PM]", "%z": "[+HHMM|-HHMM]" } for key, val in mapping.items(): format_string = format_string.replace(key, val) return format_string class Field(object): read_only = True creation_counter = 0 empty = '' type_name = None partial = False use_files = False form_field_class = forms.CharField def __init__(self, source=None): self.parent = None self.creation_counter = Field.creation_counter Field.creation_counter += 1 self.source = source def initialize(self, parent, field_name): """ Called to set up a field prior to field_to_native or field_from_native. parent - The parent serializer. model_field - The model field this field corresponds to, if one exists. """ self.parent = parent self.root = parent.root or parent self.context = self.root.context self.partial = self.root.partial if self.partial: self.required = False def field_from_native(self, data, files, field_name, into): """ Given a dictionary and a field name, updates the dictionary `into`, with the field and it's deserialized value. """ return def field_to_native(self, obj, field_name): """ Given and object and a field name, returns the value that should be serialized for that field. """ if obj is None: return self.empty if self.source == '*': return self.to_native(obj) source = self.source or field_name value = obj for component in source.split('.'): value = get_component(value, component) if value is None: break return self.to_native(value) def to_native(self, value): """ Converts the field's value into it's simple representation. """ if is_simple_callable(value): value = value() if is_protected_type(value): return value elif hasattr(value, '__iter__') and not isinstance(value, (dict, six.string_types)): return [self.to_native(item) for item in value] elif isinstance(value, dict): return dict(map(self.to_native, (k, v)) for k, v in value.items()) return smart_text(value) def attributes(self): """ Returns a dictionary of attributes to be used when serializing to xml. """ if self.type_name: return {'type': self.type_name} return {} class WritableField(Field): """ Base for read/write fields. """ default_validators = [] default_error_messages = { 'required': _('This field is required.'), 'invalid': _('Invalid value.'), } widget = widgets.TextInput default = None def __init__(self, source=None, read_only=False, required=None, validators=[], error_messages=None, widget=None, default=None, blank=None): # 'blank' is to be deprecated in favor of 'required' if blank is not None: warnings.warn('The `blank` keyword argument is due to deprecated. ' 'Use the `required` keyword argument instead.', PendingDeprecationWarning, stacklevel=2) required = not(blank) super(WritableField, self).__init__(source=source) self.read_only = read_only if required is None: self.required = not(read_only) else: assert not (read_only and required), "Cannot set required=True and read_only=True" self.required = required messages = {} for c in reversed(self.__class__.__mro__): messages.update(getattr(c, 'default_error_messages', {})) messages.update(error_messages or {}) self.error_messages = messages self.validators = self.default_validators + validators self.default = default if default is not None else self.default # Widgets are ony used for HTML forms. widget = widget or self.widget if isinstance(widget, type): widget = widget() self.widget = widget def validate(self, value): if value in validators.EMPTY_VALUES and self.required: raise ValidationError(self.error_messages['required']) def run_validators(self, value): if value in validators.EMPTY_VALUES: return errors = [] for v in self.validators: try: v(value) except ValidationError as e: if hasattr(e, 'code') and e.code in self.error_messages: message = self.error_messages[e.code] if e.params: message = message % e.params errors.append(message) else: errors.extend(e.messages) if errors: raise ValidationError(errors) def field_from_native(self, data, files, field_name, into): """ Given a dictionary and a field name, updates the dictionary `into`, with the field and it's deserialized value. """ if self.read_only: return try: if self.use_files: files = files or {} native = files[field_name] else: native = data[field_name] except KeyError: if self.default is not None and not self.partial: # Note: partial updates shouldn't set defaults native = self.default else: if self.required: raise ValidationError(self.error_messages['required']) return value = self.from_native(native) if self.source == '*': if value: into.update(value) else: self.validate(value) self.run_validators(value) into[self.source or field_name] = value def from_native(self, value): """ Reverts a simple representation back to the field's value. """ return value class ModelField(WritableField): """ A generic field that can be used against an arbitrary model field. """ def __init__(self, *args, **kwargs): try: self.model_field = kwargs.pop('model_field') except KeyError: raise ValueError("ModelField requires 'model_field' kwarg") self.min_length = kwargs.pop('min_length', getattr(self.model_field, 'min_length', None)) self.max_length = kwargs.pop('max_length', getattr(self.model_field, 'max_length', None)) super(ModelField, self).__init__(*args, **kwargs) if self.min_length is not None: self.validators.append(validators.MinLengthValidator(self.min_length)) if self.max_length is not None: self.validators.append(validators.MaxLengthValidator(self.max_length)) def from_native(self, value): rel = getattr(self.model_field, "rel", None) if rel is not None: return rel.to._meta.get_field(rel.field_name).to_python(value) else: return self.model_field.to_python(value) def field_to_native(self, obj, field_name): value = self.model_field._get_val_from_obj(obj) if is_protected_type(value): return value return self.model_field.value_to_string(obj) def attributes(self): return { "type": self.model_field.get_internal_type() } ##### Typed Fields ##### class BooleanField(WritableField): type_name = 'BooleanField' form_field_class = forms.BooleanField widget = widgets.CheckboxInput default_error_messages = { 'invalid': _("'%s' value must be either True or False."), } empty = False # Note: we set default to `False` in order to fill in missing value not # supplied by html form. TODO: Fix so that only html form input gets # this behavior. default = False def from_native(self, value): if value in ('true', 't', 'True', '1'): return True if value in ('false', 'f', 'False', '0'): return False return bool(value) class CharField(WritableField): type_name = 'CharField' form_field_class = forms.CharField def __init__(self, max_length=None, min_length=None, *args, **kwargs): self.max_length, self.min_length = max_length, min_length super(CharField, self).__init__(*args, **kwargs) if min_length is not None: self.validators.append(validators.MinLengthValidator(min_length)) if max_length is not None: self.validators.append(validators.MaxLengthValidator(max_length)) def from_native(self, value): if isinstance(value, six.string_types) or value is None: return value return smart_text(value) class URLField(CharField): type_name = 'URLField' def __init__(self, **kwargs): kwargs['max_length'] = kwargs.get('max_length', 200) kwargs['validators'] = [validators.URLValidator()] super(URLField, self).__init__(**kwargs) class SlugField(CharField): type_name = 'SlugField' def __init__(self, *args, **kwargs): kwargs['max_length'] = kwargs.get('max_length', 50) super(SlugField, self).__init__(*args, **kwargs) class ChoiceField(WritableField): type_name = 'ChoiceField' form_field_class = forms.ChoiceField widget = widgets.Select default_error_messages = { 'invalid_choice': _('Select a valid choice. %(value)s is not one of ' 'the available choices.'), } def __init__(self, choices=(), *args, **kwargs): super(ChoiceField, self).__init__(*args, **kwargs) self.choices = choices def _get_choices(self): return self._choices def _set_choices(self, value): # Setting choices also sets the choices on the widget. # choices can be any iterable, but we call list() on it because # it will be consumed more than once. self._choices = self.widget.choices = list(value) choices = property(_get_choices, _set_choices) def validate(self, value): """ Validates that the input is in self.choices. """ super(ChoiceField, self).validate(value) if value and not self.valid_value(value): raise ValidationError(self.error_messages['invalid_choice'] % {'value': value}) def valid_value(self, value): """ Check to see if the provided value is a valid choice. """ for k, v in self.choices: if isinstance(v, (list, tuple)): # This is an optgroup, so look inside the group for options for k2, v2 in v: if value == smart_text(k2): return True else: if value == smart_text(k) or value == k: return True return False class EmailField(CharField): type_name = 'EmailField' form_field_class = forms.EmailField default_error_messages = { 'invalid': _('Enter a valid e-mail address.'), } default_validators = [validators.validate_email] def from_native(self, value): ret = super(EmailField, self).from_native(value) if ret is None: return None return ret.strip() def __deepcopy__(self, memo): result = copy.copy(self) memo[id(self)] = result #result.widget = copy.deepcopy(self.widget, memo) result.validators = self.validators[:] return result class RegexField(CharField): type_name = 'RegexField' form_field_class = forms.RegexField def __init__(self, regex, max_length=None, min_length=None, *args, **kwargs): super(RegexField, self).__init__(max_length, min_length, *args, **kwargs) self.regex = regex def _get_regex(self): return self._regex def _set_regex(self, regex): if isinstance(regex, six.string_types): regex = re.compile(regex) self._regex = regex if hasattr(self, '_regex_validator') and self._regex_validator in self.validators: self.validators.remove(self._regex_validator) self._regex_validator = validators.RegexValidator(regex=regex) self.validators.append(self._regex_validator) regex = property(_get_regex, _set_regex) def __deepcopy__(self, memo): result = copy.copy(self) memo[id(self)] = result result.validators = self.validators[:] return result class DateField(WritableField): type_name = 'DateField' widget = widgets.DateInput form_field_class = forms.DateField default_error_messages = { 'invalid': _("Date has wrong format. Use one of these formats instead: %s"), } empty = None input_formats = api_settings.DATE_INPUT_FORMATS format = None def __init__(self, input_formats=None, format=None, *args, **kwargs): self.input_formats = input_formats if input_formats is not None else self.input_formats self.format = format if format is not None else self.format super(DateField, self).__init__(*args, **kwargs) def from_native(self, value): if value in validators.EMPTY_VALUES: return None if isinstance(value, datetime.datetime): if timezone and settings.USE_TZ and timezone.is_aware(value): # Convert aware datetimes to the default time zone # before casting them to dates (#17742). default_timezone = timezone.get_default_timezone() value = timezone.make_naive(value, default_timezone) return value.date() if isinstance(value, datetime.date): return value for format in self.input_formats: if format.lower() == ISO_8601: try: parsed = parse_date(value) except (ValueError, TypeError): pass else: if parsed is not None: return parsed else: try: parsed = datetime.datetime.strptime(value, format) except (ValueError, TypeError): pass else: return parsed.date() msg = self.error_messages['invalid'] % readable_date_formats(self.input_formats) raise ValidationError(msg) def to_native(self, value): if value is None or self.format is None: return value if isinstance(value, datetime.datetime): value = value.date() if self.format.lower() == ISO_8601: return value.isoformat() return value.strftime(self.format) class DateTimeField(WritableField): type_name = 'DateTimeField' widget = widgets.DateTimeInput form_field_class = forms.DateTimeField default_error_messages = { 'invalid': _("Datetime has wrong format. Use one of these formats instead: %s"), } empty = None input_formats = api_settings.DATETIME_INPUT_FORMATS format = None def __init__(self, input_formats=None, format=None, *args, **kwargs): self.input_formats = input_formats if input_formats is not None else self.input_formats self.format = format if format is not None else self.format super(DateTimeField, self).__init__(*args, **kwargs) def from_native(self, value): if value in validators.EMPTY_VALUES: return None if isinstance(value, datetime.datetime): return value if isinstance(value, datetime.date): value = datetime.datetime(value.year, value.month, value.day) if settings.USE_TZ: # For backwards compatibility, interpret naive datetimes in # local time. This won't work during DST change, but we can't # do much about it, so we let the exceptions percolate up the # call stack. warnings.warn("DateTimeField received a naive datetime (%s)" " while time zone support is active." % value, RuntimeWarning) default_timezone = timezone.get_default_timezone() value = timezone.make_aware(value, default_timezone) return value for format in self.input_formats: if format.lower() == ISO_8601: try: parsed = parse_datetime(value) except (ValueError, TypeError): pass else: if parsed is not None: return parsed else: try: parsed = datetime.datetime.strptime(value, format) except (ValueError, TypeError): pass else: return parsed msg = self.error_messages['invalid'] % readable_datetime_formats(self.input_formats) raise ValidationError(msg) def to_native(self, value): if value is None or self.format is None: return value if self.format.lower() == ISO_8601: ret = value.isoformat() if ret.endswith('+00:00'): ret = ret[:-6] + 'Z' return ret return value.strftime(self.format) class TimeField(WritableField): type_name = 'TimeField' widget = widgets.TimeInput form_field_class = forms.TimeField default_error_messages = { 'invalid': _("Time has wrong format. Use one of these formats instead: %s"), } empty = None input_formats = api_settings.TIME_INPUT_FORMATS format = None def __init__(self, input_formats=None, format=None, *args, **kwargs): self.input_formats = input_formats if input_formats is not None else self.input_formats self.format = format if format is not None else self.format super(TimeField, self).__init__(*args, **kwargs) def from_native(self, value): if value in validators.EMPTY_VALUES: return None if isinstance(value, datetime.time): return value for format in self.input_formats: if format.lower() == ISO_8601: try: parsed = parse_time(value) except (ValueError, TypeError): pass else: if parsed is not None: return parsed else: try: parsed = datetime.datetime.strptime(value, format) except (ValueError, TypeError): pass else: return parsed.time() msg = self.error_messages['invalid'] % readable_time_formats(self.input_formats) raise ValidationError(msg) def to_native(self, value): if value is None or self.format is None: return value if isinstance(value, datetime.datetime): value = value.time() if self.format.lower() == ISO_8601: return value.isoformat() return value.strftime(self.format) class IntegerField(WritableField): type_name = 'IntegerField' form_field_class = forms.IntegerField default_error_messages = { 'invalid': _('Enter a whole number.'), 'max_value': _('Ensure this value is less than or equal to %(limit_value)s.'), 'min_value': _('Ensure this value is greater than or equal to %(limit_value)s.'), } def __init__(self, max_value=None, min_value=None, *args, **kwargs): self.max_value, self.min_value = max_value, min_value super(IntegerField, self).__init__(*args, **kwargs) if max_value is not None: self.validators.append(validators.MaxValueValidator(max_value)) if min_value is not None: self.validators.append(validators.MinValueValidator(min_value)) def from_native(self, value): if value in validators.EMPTY_VALUES: return None try: value = int(str(value)) except (ValueError, TypeError): raise ValidationError(self.error_messages['invalid']) return value class FloatField(WritableField): type_name = 'FloatField' form_field_class = forms.FloatField default_error_messages = { 'invalid': _("'%s' value must be a float."), } def from_native(self, value): if value in validators.EMPTY_VALUES: return None try: return float(value) except (TypeError, ValueError): msg = self.error_messages['invalid'] % value raise ValidationError(msg) class DecimalField(WritableField): type_name = 'DecimalField' form_field_class = forms.DecimalField default_error_messages = { 'invalid': _('Enter a number.'), 'max_value': _('Ensure this value is less than or equal to %(limit_value)s.'), 'min_value': _('Ensure this value is greater than or equal to %(limit_value)s.'), 'max_digits': _('Ensure that there are no more than %s digits in total.'), 'max_decimal_places': _('Ensure that there are no more than %s decimal places.'), 'max_whole_digits': _('Ensure that there are no more than %s digits before the decimal point.') } def __init__(self, max_value=None, min_value=None, max_digits=None, decimal_places=None, *args, **kwargs): self.max_value, self.min_value = max_value, min_value self.max_digits, self.decimal_places = max_digits, decimal_places super(DecimalField, self).__init__(*args, **kwargs) if max_value is not None: self.validators.append(validators.MaxValueValidator(max_value)) if min_value is not None: self.validators.append(validators.MinValueValidator(min_value)) def from_native(self, value): """ Validates that the input is a decimal number. Returns a Decimal instance. Returns None for empty values. Ensures that there are no more than max_digits in the number, and no more than decimal_places digits after the decimal point. """ if value in validators.EMPTY_VALUES: return None value = smart_text(value).strip() try: value = Decimal(value) except DecimalException: raise ValidationError(self.error_messages['invalid']) return value def validate(self, value): super(DecimalField, self).validate(value) if value in validators.EMPTY_VALUES: return # Check for NaN, Inf and -Inf values. We can't compare directly for NaN, # since it is never equal to itself. However, NaN is the only value that # isn't equal to itself, so we can use this to identify NaN if value != value or value == Decimal("Inf") or value == Decimal("-Inf"): raise ValidationError(self.error_messages['invalid']) sign, digittuple, exponent = value.as_tuple() decimals = abs(exponent) # digittuple doesn't include any leading zeros. digits = len(digittuple) if decimals > digits: # We have leading zeros up to or past the decimal point. Count # everything past the decimal point as a digit. We do not count # 0 before the decimal point as a digit since that would mean # we would not allow max_digits = decimal_places. digits = decimals whole_digits = digits - decimals if self.max_digits is not None and digits > self.max_digits: raise ValidationError(self.error_messages['max_digits'] % self.max_digits) if self.decimal_places is not None and decimals > self.decimal_places: raise ValidationError(self.error_messages['max_decimal_places'] % self.decimal_places) if self.max_digits is not None and self.decimal_places is not None and whole_digits > (self.max_digits - self.decimal_places): raise ValidationError(self.error_messages['max_whole_digits'] % (self.max_digits - self.decimal_places)) return value class FileField(WritableField): use_files = True type_name = 'FileField' form_field_class = forms.FileField widget = widgets.FileInput default_error_messages = { 'invalid': _("No file was submitted. Check the encoding type on the form."), 'missing': _("No file was submitted."), 'empty': _("The submitted file is empty."), 'max_length': _('Ensure this filename has at most %(max)d characters (it has %(length)d).'), 'contradiction': _('Please either submit a file or check the clear checkbox, not both.') } def __init__(self, *args, **kwargs): self.max_length = kwargs.pop('max_length', None) self.allow_empty_file = kwargs.pop('allow_empty_file', False) super(FileField, self).__init__(*args, **kwargs) def from_native(self, data): if data in validators.EMPTY_VALUES: return None # UploadedFile objects should have name and size attributes. try: file_name = data.name file_size = data.size except AttributeError: raise ValidationError(self.error_messages['invalid']) if self.max_length is not None and len(file_name) > self.max_length: error_values = {'max': self.max_length, 'length': len(file_name)} raise ValidationError(self.error_messages['max_length'] % error_values) if not file_name: raise ValidationError(self.error_messages['invalid']) if not self.allow_empty_file and not file_size: raise ValidationError(self.error_messages['empty']) return data def to_native(self, value): return value.name class ImageField(FileField): use_files = True form_field_class = forms.ImageField default_error_messages = { 'invalid_image': _("Upload a valid image. The file you uploaded was " "either not an image or a corrupted image."), } def from_native(self, data): """ Checks that the file-upload field data contains a valid image (GIF, JPG, PNG, possibly others -- whatever the Python Imaging Library supports). """ f = super(ImageField, self).from_native(data) if f is None: return None from compat import Image assert Image is not None, 'PIL must be installed for ImageField support' # We need to get a file object for PIL. We might have a path or we might # have to read the data into memory. if hasattr(data, 'temporary_file_path'): file = data.temporary_file_path() else: if hasattr(data, 'read'): file = BytesIO(data.read()) else: file = BytesIO(data['content']) try: # load() could spot a truncated JPEG, but it loads the entire # image in memory, which is a DoS vector. See #3848 and #18520. # verify() must be called immediately after the constructor. Image.open(file).verify() except ImportError: # Under PyPy, it is possible to import PIL. However, the underlying # _imaging C module isn't available, so an ImportError will be # raised. Catch and re-raise. raise except Exception: # Python Imaging Library doesn't recognize it as an image raise ValidationError(self.error_messages['invalid_image']) if hasattr(f, 'seek') and callable(f.seek): f.seek(0) return f class SerializerMethodField(Field): """ A field that gets its value by calling a method on the serializer it's attached to. """ def __init__(self, method_name): self.method_name = method_name super(SerializerMethodField, self).__init__() def field_to_native(self, obj, field_name): value = getattr(self.parent, self.method_name)(obj) return self.to_native(value)