root/django/branches/newforms-admin/django/newforms/fields.py

"""
Field classes.
"""

import copy
import datetime
import os
import re
import time
try:
    from cStringIO import StringIO
except ImportError:
    from StringIO import StringIO

# Python 2.3 fallbacks
try:
    from decimal import Decimal, DecimalException
except ImportError:
    from django.utils._decimal import Decimal, DecimalException
try:
    set
except NameError:
    from sets import Set as set

from django.utils.translation import ugettext_lazy as _
from django.utils.encoding import StrAndUnicode, smart_unicode, smart_str

from util import ErrorList, ValidationError
from widgets import TextInput, PasswordInput, HiddenInput, MultipleHiddenInput, FileInput, CheckboxInput, Select, NullBooleanSelect, SelectMultiple, DateTimeInput
from django.core.files.uploadedfile import SimpleUploadedFile as UploadedFile

__all__ = (
    'Field', 'CharField', 'IntegerField',
    'DEFAULT_DATE_INPUT_FORMATS', 'DateField',
    'DEFAULT_TIME_INPUT_FORMATS', 'TimeField',
    'DEFAULT_DATETIME_INPUT_FORMATS', 'DateTimeField',
    'RegexField', 'EmailField', 'FileField', 'ImageField', 'URLField',
    'BooleanField', 'NullBooleanField', 'ChoiceField', 'MultipleChoiceField',
    'ComboField', 'MultiValueField', 'FloatField', 'DecimalField',
    'SplitDateTimeField', 'IPAddressField', 'FilePathField',
)

# These values, if given to to_python(), will trigger the self.required check.
EMPTY_VALUES = (None, '')


class Field(object):
    widget = TextInput # Default widget to use when rendering this type of Field.
    hidden_widget = HiddenInput # Default widget to use when rendering this as "hidden".
    default_error_messages = {
        'required': _(u'This field is required.'),
        'invalid': _(u'Enter a valid value.'),
    }

    # Tracks each time a Field instance is created. Used to retain order.
    creation_counter = 0

    def __init__(self, required=True, widget=None, label=None, initial=None,
                 help_text=None, error_messages=None):
        # required -- Boolean that specifies whether the field is required.
        #             True by default.
        # widget -- A Widget class, or instance of a Widget class, that should
        #           be used for this Field when displaying it. Each Field has a
        #           default Widget that it'll use if you don't specify this. In
        #           most cases, the default widget is TextInput.
        # label -- A verbose name for this field, for use in displaying this
        #          field in a form. By default, Django will use a "pretty"
        #          version of the form field name, if the Field is part of a
        #          Form.
        # initial -- A value to use in this Field's initial display. This value
        #            is *not* used as a fallback if data isn't given.
        # help_text -- An optional string to use as "help text" for this Field.
        if label is not None:
            label = smart_unicode(label)
        self.required, self.label, self.initial = required, label, initial
        self.help_text = smart_unicode(help_text or '')
        widget = widget or self.widget
        if isinstance(widget, type):
            widget = widget()

        # Hook into self.widget_attrs() for any Field-specific HTML attributes.
        extra_attrs = self.widget_attrs(widget)
        if extra_attrs:
            widget.attrs.update(extra_attrs)

        self.widget = widget

        # Increase the creation counter, and save our local copy.
        self.creation_counter = Field.creation_counter
        Field.creation_counter += 1

        def set_class_error_messages(messages, klass):
            for base_class in klass.__bases__:
                set_class_error_messages(messages, base_class)
            messages.update(getattr(klass, 'default_error_messages', {}))

        messages = {}
        set_class_error_messages(messages, self.__class__)
        messages.update(error_messages or {})
        self.error_messages = messages

    def clean(self, value):
        """
        Validates the given value and returns its "cleaned" value as an
        appropriate Python object.

        Raises ValidationError for any errors.
        """
        if self.required and value in EMPTY_VALUES:
            raise ValidationError(self.error_messages['required'])
        return value

    def widget_attrs(self, widget):
        """
        Given a Widget instance (*not* a Widget class), returns a dictionary of
        any HTML attributes that should be added to the Widget, based on this
        Field.
        """
        return {}

    def __deepcopy__(self, memo):
        result = copy.copy(self)
        memo[id(self)] = result
        result.widget = copy.deepcopy(self.widget, memo)
        return result

class CharField(Field):
    default_error_messages = {
        'max_length': _(u'Ensure this value has at most %(max)d characters (it has %(length)d).'),
        'min_length': _(u'Ensure this value has at least %(min)d characters (it has %(length)d).'),
    }

    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)

    def clean(self, value):
        "Validates max_length and min_length. Returns a Unicode object."
        super(CharField, self).clean(value)
        if value in EMPTY_VALUES:
            return u''
        value = smart_unicode(value)
        value_length = len(value)
        if self.max_length is not None and value_length > self.max_length:
            raise ValidationError(self.error_messages['max_length'] % {'max': self.max_length, 'length': value_length})
        if self.min_length is not None and value_length < self.min_length:
            raise ValidationError(self.error_messages['min_length'] % {'min': self.min_length, 'length': value_length})
        return value

    def widget_attrs(self, widget):
        if self.max_length is not None and isinstance(widget, (TextInput, PasswordInput)):
            # The HTML attribute is maxlength, not max_length.
            return {'maxlength': str(self.max_length)}

class IntegerField(Field):
    default_error_messages = {
        'invalid': _(u'Enter a whole number.'),
        'max_value': _(u'Ensure this value is less than or equal to %s.'),
        'min_value': _(u'Ensure this value is greater than or equal to %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)

    def clean(self, value):
        """
        Validates that int() can be called on the input. Returns the result
        of int(). Returns None for empty values.
        """
        super(IntegerField, self).clean(value)
        if value in EMPTY_VALUES:
            return None
        try:
            value = int(str(value))
        except (ValueError, TypeError):
            raise ValidationError(self.error_messages['invalid'])
        if self.max_value is not None and value > self.max_value:
            raise ValidationError(self.error_messages['max_value'] % self.max_value)
        if self.min_value is not None and value < self.min_value:
            raise ValidationError(self.error_messages['min_value'] % self.min_value)
        return value

class FloatField(Field):
    default_error_messages = {
        'invalid': _(u'Enter a number.'),
        'max_value': _(u'Ensure this value is less than or equal to %s.'),
        'min_value': _(u'Ensure this value is greater than or equal to %s.'),
    }

    def __init__(self, max_value=None, min_value=None, *args, **kwargs):
        self.max_value, self.min_value = max_value, min_value
        Field.__init__(self, *args, **kwargs)

    def clean(self, value):
        """
        Validates that float() can be called on the input. Returns a float.
        Returns None for empty values.
        """
        super(FloatField, self).clean(value)
        if not self.required and value in EMPTY_VALUES:
            return None
        try:
            value = float(value)
        except (ValueError, TypeError):
            raise ValidationError(self.error_messages['invalid'])
        if self.max_value is not None and value > self.max_value:
            raise ValidationError(self.error_messages['max_value'] % self.max_value)
        if self.min_value is not None and value < self.min_value:
            raise ValidationError(self.error_messages['min_value'] % self.min_value)
        return value

class DecimalField(Field):
    default_error_messages = {
        'invalid': _(u'Enter a number.'),
        'max_value': _(u'Ensure this value is less than or equal to %s.'),
        'min_value': _(u'Ensure this value is greater than or equal to %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
        Field.__init__(self, *args, **kwargs)

    def clean(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.
        """
        super(DecimalField, self).clean(value)
        if not self.required and value in EMPTY_VALUES:
            return None
        value = smart_str(value).strip()
        try:
            value = Decimal(value)
        except DecimalException:
            raise ValidationError(self.error_messages['invalid'])
        pieces = str(value).lstrip("-").split('.')
        decimals = (len(pieces) == 2) and len(pieces[1]) or 0
        digits = len(pieces[0])
        if self.max_value is not None and value > self.max_value:
            raise ValidationError(self.error_messages['max_value'] % self.max_value)
        if self.min_value is not None and value < self.min_value:
            raise ValidationError(self.error_messages['min_value'] % self.min_value)
        if self.max_digits is not None and (digits + decimals) > 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 digits > (self.max_digits - self.decimal_places):
            raise ValidationError(self.error_messages['max_whole_digits'] % (self.max_digits - self.decimal_places))
        return value

DEFAULT_DATE_INPUT_FORMATS = (
    '%Y-%m-%d', '%m/%d/%Y', '%m/%d/%y', # '2006-10-25', '10/25/2006', '10/25/06'
    '%b %d %Y', '%b %d, %Y',            # 'Oct 25 2006', 'Oct 25, 2006'
    '%d %b %Y', '%d %b, %Y',            # '25 Oct 2006', '25 Oct, 2006'
    '%B %d %Y', '%B %d, %Y',            # 'October 25 2006', 'October 25, 2006'
    '%d %B %Y', '%d %B, %Y',            # '25 October 2006', '25 October, 2006'
)

class DateField(Field):
    default_error_messages = {
        'invalid': _(u'Enter a valid date.'),
    }

    def __init__(self, input_formats=None, *args, **kwargs):
        super(DateField, self).__init__(*args, **kwargs)
        self.input_formats = input_formats or DEFAULT_DATE_INPUT_FORMATS

    def clean(self, value):
        """
        Validates that the input can be converted to a date. Returns a Python
        datetime.date object.
        """
        super(DateField, self).clean(value)
        if value in EMPTY_VALUES:
            return None
        if isinstance(value, datetime.datetime):
            return value.date()
        if isinstance(value, datetime.date):
            return value
        for format in self.input_formats:
            try:
                return datetime.date(*time.strptime(value, format)[:3])
            except ValueError:
                continue
        raise ValidationError(self.error_messages['invalid'])

DEFAULT_TIME_INPUT_FORMATS = (
    '%H:%M:%S',     # '14:30:59'
    '%H:%M',        # '14:30'
)

class TimeField(Field):
    default_error_messages = {
        'invalid': _(u'Enter a valid time.')
    }

    def __init__(self, input_formats=None, *args, **kwargs):
        super(TimeField, self).__init__(*args, **kwargs)
        self.input_formats = input_formats or DEFAULT_TIME_INPUT_FORMATS

    def clean(self, value):
        """
        Validates that the input can be converted to a time. Returns a Python
        datetime.time object.
        """
        super(TimeField, self).clean(value)
        if value in EMPTY_VALUES:
            return None
        if isinstance(value, datetime.time):
            return value
        for format in self.input_formats:
            try:
                return datetime.time(*time.strptime(value, format)[3:6])
            except ValueError:
                continue
        raise ValidationError(self.error_messages['invalid'])

DEFAULT_DATETIME_INPUT_FORMATS = (
    '%Y-%m-%d %H:%M:%S',     # '2006-10-25 14:30:59'
    '%Y-%m-%d %H:%M',        # '2006-10-25 14:30'
    '%Y-%m-%d',              # '2006-10-25'
    '%m/%d/%Y %H:%M:%S',     # '10/25/2006 14:30:59'
    '%m/%d/%Y %H:%M',        # '10/25/2006 14:30'
    '%m/%d/%Y',              # '10/25/2006'
    '%m/%d/%y %H:%M:%S',     # '10/25/06 14:30:59'
    '%m/%d/%y %H:%M',        # '10/25/06 14:30'
    '%m/%d/%y',              # '10/25/06'
)

class DateTimeField(Field):
    widget = DateTimeInput
    default_error_messages = {
        'invalid': _(u'Enter a valid date/time.'),
    }

    def __init__(self, input_formats=None, *args, **kwargs):
        super(DateTimeField, self).__init__(*args, **kwargs)
        self.input_formats = input_formats or DEFAULT_DATETIME_INPUT_FORMATS

    def clean(self, value):
        """
        Validates that the input can be converted to a datetime. Returns a
        Python datetime.datetime object.
        """
        super(DateTimeField, self).clean(value)
        if value in EMPTY_VALUES:
            return None
        if isinstance(value, datetime.datetime):
            return value
        if isinstance(value, datetime.date):
            return datetime.datetime(value.year, value.month, value.day)
        if isinstance(value, list):
            # Input comes from a SplitDateTimeWidget, for example. So, it's two
            # components: date and time.
            if len(value) != 2:
                raise ValidationError(self.error_messages['invalid'])
            value = '%s %s' % tuple(value)
        for format in self.input_formats:
            try:
                return datetime.datetime(*time.strptime(value, format)[:6])
            except ValueError:
                continue
        raise ValidationError(self.error_messages['invalid'])

class RegexField(CharField):
    def __init__(self, regex, max_length=None, min_length=None, error_message=None, *args, **kwargs):
        """
        regex can be either a string or a compiled regular expression object.
        error_message is an optional error message to use, if
        'Enter a valid value' is too generic for you.
        """
        # error_message is just kept for backwards compatibility:
        if error_message:
            error_messages = kwargs.get('error_messages') or {}
            error_messages['invalid'] = error_message
            kwargs['error_messages'] = error_messages
        super(RegexField, self).__init__(max_length, min_length, *args, **kwargs)
        if isinstance(regex, basestring):
            regex = re.compile(regex)
        self.regex = regex

    def clean(self, value):
        """
        Validates that the input matches the regular expression. Returns a
        Unicode object.
        """
        value = super(RegexField, self).clean(value)
        if value == u'':
            return value
        if not self.regex.search(value):
            raise ValidationError(self.error_messages['invalid'])
        return value

email_re = re.compile(
    r"(^[-!#$%&'*+/=?^_`{}|~0-9A-Z]+(\.[-!#$%&'*+/=?^_`{}|~0-9A-Z]+)*"  # dot-atom
    r'|^"([\001-\010\013\014\016-\037!#-\[\]-\177]|\\[\001-011\013\014\016-\177])*"' # quoted-string
    r')@(?:[A-Z0-9-]+\.)+[A-Z]{2,6}$', re.IGNORECASE)  # domain

class EmailField(RegexField):
    default_error_messages = {
        'invalid': _(u'Enter a valid e-mail address.'),
    }

    def __init__(self, max_length=None, min_length=None, *args, **kwargs):
        RegexField.__init__(self, email_re, max_length, min_length, *args,
                            **kwargs)

try:
    from django.conf import settings
    URL_VALIDATOR_USER_AGENT = settings.URL_VALIDATOR_USER_AGENT
except ImportError:
    # It's OK if Django settings aren't configured.
    URL_VALIDATOR_USER_AGENT = 'Django (http://www.djangoproject.com/)'


class FileField(Field):
    widget = FileInput
    default_error_messages = {
        'invalid': _(u"No file was submitted. Check the encoding type on the form."),
        'missing': _(u"No file was submitted."),
        'empty': _(u"The submitted file is empty."),
    }

    def __init__(self, *args, **kwargs):
        super(FileField, self).__init__(*args, **kwargs)

    def clean(self, data, initial=None):
        super(FileField, self).clean(initial or data)
        if not self.required and data in EMPTY_VALUES:
            return None
        elif not data and initial:
            return initial

        if isinstance(data, dict):
            # We warn once, then support both ways below.
            import warnings
            warnings.warn(
                message = "Representing uploaded files as dictionaries is deprecated. Use django.core.files.uploadedfile.SimpleUploadedFile instead.",
                category = DeprecationWarning,
                stacklevel = 2
            )
            data = UploadedFile(data['filename'], data['content'])

        try:
            file_name = data.name
            file_size = data.size
        except AttributeError:
            raise ValidationError(self.error_messages['invalid'])

        if not file_name:
            raise ValidationError(self.error_messages['invalid'])
        if not file_size:
            raise ValidationError(self.error_messages['empty'])

        return data

class ImageField(FileField):
    default_error_messages = {
        'invalid_image': _(u"Upload a valid image. The file you uploaded was either not an image or a corrupted image."),
    }

    def clean(self, data, initial=None):
        """
        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).clean(data, initial)
        if f is None:
            return None
        elif not data and initial:
            return initial
        from PIL import Image

        # 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 = StringIO(data.read())
            else:
                file = StringIO(data['content'])

        try:
            # load() is the only method that can spot a truncated JPEG,
            #  but it cannot be called sanely after verify()
            trial_image = Image.open(file)