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mobile-demo-set / lib / wtforms / fields.py

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import datetime
import decimal
import itertools
import time

from wtforms import widgets
from wtforms.validators import StopValidation


__all__ = (
    'BooleanField', 'DecimalField', 'DateField', 'DateTimeField', 'FieldList',
    'FileField', 'FloatField', 'FormField', 'HiddenField', 'IntegerField',
    'PasswordField', 'RadioField', 'SelectField', 'SelectMultipleField',
    'SubmitField', 'TextField', 'TextAreaField',
)


_unset_value = object()


class DummyTranslations(object):
    def gettext(self, string):
        return string

    def ngettext(self, singular, plural, n):
        if n == 1:
            return singular

        return plural


class Field(object):
    """
    Field base class
    """
    widget = None
    errors = tuple()
    process_errors = tuple()
    _formfield = True
    _translations = DummyTranslations()

    def __new__(cls, *args, **kwargs):
        if '_form' in kwargs and '_name' in kwargs:
            return super(Field, cls).__new__(cls)
        else:
            return UnboundField(cls, *args, **kwargs)

    def __init__(self, label=u'', validators=None, filters=tuple(),
                 description=u'', id=None, default=None, widget=None,
                 _form=None, _name=None, _prefix='', _translations=None):
        """
        Construct a new field.

        :param label:
            The label of the field. Available after construction through the
            `label` property.
        :param validators:
            A sequence of validators to call when `validate` is called.
        :param filters:
            A sequence of filters which are run on input data by `process`.
        :param description:
            A description for the field, typically used for help text.
        :param id:
            An id to use for the field. A reasonable default is set by the form,
            and you shouldn't need to set this manually.
        :param default:
            The default value to assign to the field, if no form or object
            input is provided. May be a callable.
        :param widget:
            If provided, overrides the widget used to render the field.
        :param _form:
            The form holding this field. It is passed by the form itself during
            construction. You should never pass this value yourself.
        :param _name:
            The name of this field, passed by the enclosing form during its
            construction. You should never pass this value yourself.
        :param _prefix:
            The prefix to prepend to the form name of this field, passed by
            the enclosing form during construction.

        If `_form` and `_name` isn't provided, an :class:`UnboundField` will be
        returned instead. Call its :func:`bind` method with a form instance and
        a name to construct the field.
        """
        self.short_name = _name
        self.name = _prefix + _name
        if _translations is not None:
            self._translations = _translations
        self.id = id or self.name
        self.label = Label(self.id, label or _name.replace('_', ' ').title())
        if validators is None:
            validators = []
        self.validators = validators
        self.filters = filters
        self.description = description
        self.type = type(self).__name__
        self.default = default
        self.raw_data = None
        if widget:
            self.widget = widget
        self.flags = Flags()
        for v in validators:
            flags = getattr(v, 'field_flags', ())
            for f in flags:
                setattr(self.flags, f, True)

    def __unicode__(self):
        """
        Returns a HTML representation of the field. For more powerful rendering,
        see the `__call__` method.
        """
        return self()

    def __str__(self):
        """
        Returns a HTML representation of the field. For more powerful rendering,
        see the `__call__` method.
        """
        return self()

    def __html__(self):
        """
        Returns a HTML representation of the field. For more powerful rendering,
        see the `__call__` method.
        """
        return self()

    def __call__(self, **kwargs):
        """
        Render this field as HTML, using keyword args as additional attributes.

        Any HTML attribute passed to the method will be added to the tag
        and entity-escaped properly.
        """
        return self.widget(self, **kwargs)

    def gettext(self, string):
        return self._translations.gettext(string)

    def ngettext(self, singular, plural, n):
        return self._translations.ngettext(singular, plural, n)

    def validate(self, form, extra_validators=tuple()):
        """
        Validates the field and returns True or False. `self.errors` will
        contain any errors raised during validation. This is usually only
        called by `Form.validate`.

        Subfields shouldn't override this, but rather override either
        `pre_validate`, `post_validate` or both, depending on needs.

        :param form: The form the field belongs to.
        :param extra_validators: A list of extra validators to run.
        """
        self.errors = list(self.process_errors)
        stop_validation = False

        # Call pre_validate
        try:
            self.pre_validate(form)
        except StopValidation, e:
            if e.args and e.args[0]:
                self.errors.append(e.args[0])
            stop_validation = True
        except ValueError, e:
            self.errors.append(e.args[0])

        # Run validators
        if not stop_validation:
            for validator in itertools.chain(self.validators, extra_validators):
                try:
                    validator(form, self)
                except StopValidation, e:
                    if e.args and e.args[0]:
                        self.errors.append(e.args[0])
                    stop_validation = True
                    break
                except ValueError, e:
                    self.errors.append(e.args[0])

        # Call post_validate
        try:
            self.post_validate(form, stop_validation)
        except ValueError, e:
            self.errors.append(e.args[0])

        return len(self.errors) == 0

    def pre_validate(self, form):
        """
        Override if you need field-level validation. Runs before any other
        validators.

        :param form: The form the field belongs to.
        """
        pass

    def post_validate(self, form, validation_stopped):
        """
        Override if you need to run any field-level validation tasks after
        normal validation. This shouldn't be needed in most cases.

        :param form: The form the field belongs to.
        :param validation_stopped:
            `True` if any validator raised StopValidation.
        """
        pass

    def process(self, formdata, data=_unset_value):
        """
        Process incoming data, calling process_data, process_formdata as needed,
        and run filters.

        If `data` is not provided, process_data will be called on the field's
        default.

        Field subclasses usually won't override this, instead overriding the
        process_formdata and process_data methods. Only override this for
        special advanced processing, such as when a field encapsulates many
        inputs.
        """
        self.process_errors = []
        if data is _unset_value:
            try:
                data = self.default()
            except TypeError:
                data = self.default
        try:
            self.process_data(data)
        except ValueError, e:
            self.process_errors.append(e.args[0])

        if formdata:
            try:
                if self.name in formdata:
                    self.raw_data = formdata.getlist(self.name)
                else:
                    self.raw_data = []
                self.process_formdata(self.raw_data)
            except ValueError, e:
                self.process_errors.append(e.args[0])

        for filter in self.filters:
            try:
                self.data = filter(self.data)
            except ValueError, e:
                self.process_errors.append(e.args[0])

    def process_data(self, value):
        """
        Process the Python data applied to this field and store the result.

        This will be called during form construction by the form's `kwargs` or
        `obj` argument.

        :param value: The python object containing the value to process.
        """
        self.data = value

    def process_formdata(self, valuelist):
        """
        Process data received over the wire from a form.

        This will be called during form construction with data supplied
        through the `formdata` argument.

        :param valuelist: A list of strings to process.
        """
        if valuelist:
            self.data = valuelist[0]

    def populate_obj(self, obj, name):
        """
        Populates `obj.<name>` with the field's data.

        :note: This is a destructive operation. If `obj.<name>` already exists,
               it will be overridden. Use with caution.
        """
        setattr(obj, name, self.data)


class UnboundField(object):
    _formfield = True
    creation_counter = 0

    def __init__(self, field_class, *args, **kwargs):
        UnboundField.creation_counter += 1
        self.field_class = field_class
        self.args = args
        self.kwargs = kwargs
        self.creation_counter = UnboundField.creation_counter

    def bind(self, form, name, prefix='', translations=None, **kwargs):
        return self.field_class(_form=form, _prefix=prefix, _name=name, _translations=translations, *self.args, **dict(self.kwargs, **kwargs))

    def __repr__(self):
        return '<UnboundField(%s, %r, %r)>' % (self.field_class.__name__, self.args, self.kwargs)


class Flags(object):
    """
    Holds a set of boolean flags as attributes.

    Accessing a non-existing attribute returns False for its value.
    """
    def __getattr__(self, name):
        return False

    def __contains__(self, name):
        return getattr(self, name)

    def __repr__(self):
        flags = (name for name in dir(self) if not name.startswith('_'))
        return '<wtforms.fields.Flags: {%s}>' % ', '.join(flags)


class Label(object):
    """
    An HTML form label.
    """
    def __init__(self, field_id, text):
        self.field_id = field_id
        self.text = text

    def __str__(self):
        return self()

    def __unicode__(self):
        return self()

    def __html__(self):
        return self()

    def __call__(self, text=None, **kwargs):
        kwargs['for'] = self.field_id
        attributes = widgets.html_params(**kwargs)
        return widgets.HTMLString(u'<label %s>%s</label>' % (attributes, text or self.text))

    def __repr__(self):
        return 'Label(%r, %r)' % (self.field_id, self.text)


class SelectFieldBase(Field):
    option_widget = widgets.Option()

    """
    Base class for fields which can be iterated to produce options.

    This isn't a field, but an abstract base class for fields which want to
    provide this functionality.
    """
    def __init__(self, label=u'', validators=None, option_widget=None, **kwargs):
        super(SelectFieldBase, self).__init__(label, validators, **kwargs)

        if option_widget is not None:
            self.option_widget = option_widget

    def iter_choices(self):
        """
        Provides data for choice widget rendering. Must return a sequence or
        iterable of (value, label, selected) tuples.
        """
        raise NotImplementedError()

    def __iter__(self):
        opts = dict(widget=self.option_widget, _name=self.name, _form=None)
        for i, (value, label, checked) in enumerate(self.iter_choices()):
            opt = self._Option(label=label, id=u'%s-%d' % (self.id, i), **opts)
            opt.process(None, value)
            opt.checked = checked
            yield opt

    class _Option(Field):
        checked = False

        def _value(self):
            return self.data


class SelectField(SelectFieldBase):
    widget = widgets.Select()

    def __init__(self, label=u'', validators=None, coerce=unicode, choices=None, **kwargs):
        super(SelectField, self).__init__(label, validators, **kwargs)
        self.coerce = coerce
        self.choices = choices

    def iter_choices(self):
        for value, label in self.choices:
            yield (value, label, self.coerce(value) == self.data)

    def process_data(self, value):
        try:
            self.data = self.coerce(value)
        except (ValueError, TypeError):
            self.data = None

    def process_formdata(self, valuelist):
        if valuelist:
            try:
                self.data = self.coerce(valuelist[0])
            except ValueError:
                raise ValueError(self.gettext(u'Invalid Choice: could not coerce'))

    def pre_validate(self, form):
        for v, _ in self.choices:
            if self.data == v:
                break
        else:
            raise ValueError(self.gettext(u'Not a valid choice'))


class SelectMultipleField(SelectField):
    """
    No different from a normal select field, except this one can take (and
    validate) multiple choices.  You'll need to specify the HTML `rows`
    attribute to the select field when rendering.
    """
    widget = widgets.Select(multiple=True)

    def iter_choices(self):
        for value, label in self.choices:
            selected = self.data is not None and self.coerce(value) in self.data
            yield (value, label, selected)

    def process_data(self, value):
        try:
            self.data = list(self.coerce(v) for v in value)
        except (ValueError, TypeError):
            self.data = None

    def process_formdata(self, valuelist):
        try:
            self.data = list(self.coerce(x) for x in valuelist)
        except ValueError:
            raise ValueError(self.gettext(u'Invalid choice(s): one or more data inputs could not be coerced'))

    def pre_validate(self, form):
        if self.data:
            values = list(c[0] for c in self.choices)
            for d in self.data:
                if d not in values:
                    raise ValueError(self.gettext(u"'%(value)s' is not a valid choice for this field") % dict(value=d))


class RadioField(SelectField):
    """
    Like a SelectField, except displays a list of radio buttons.

    Iterating the field will produce subfields (each containing a label as
    well) in order to allow custom rendering of the individual radio fields.
    """
    widget = widgets.ListWidget(prefix_label=False)
    option_widget = widgets.RadioInput()


class TextField(Field):
    """
    This field is the base for most of the more complicated fields, and
    represents an ``<input type="text">``.
    """
    widget = widgets.TextInput()

    def process_formdata(self, valuelist):
        if valuelist:
            self.data = valuelist[0]
        else:
            self.data = u''

    def _value(self):
        return self.data is not None and unicode(self.data) or u''


class HiddenField(TextField):
    """
    Represents an ``<input type="hidden">``.
    """
    widget = widgets.HiddenInput()


class TextAreaField(TextField):
    """
    This field represents an HTML ``<textarea>`` and can be used to take
    multi-line input.
    """
    widget = widgets.TextArea()


class PasswordField(TextField):
    """
    Represents an ``<input type="password">``.
    """
    widget = widgets.PasswordInput()


class FileField(TextField):
    """
    Can render a file-upload field.  Will take any passed filename value, if
    any is sent by the browser in the post params.  This field will NOT
    actually handle the file upload portion, as wtforms does not deal with
    individual frameworks' file handling capabilities.
    """
    widget = widgets.FileInput()


class IntegerField(TextField):
    """
    A text field, except all input is coerced to an integer.  Erroneous input
    is ignored and will not be accepted as a value.
    """
    def __init__(self, label=u'', validators=None, **kwargs):
        super(IntegerField, self).__init__(label, validators, **kwargs)

    def _value(self):
        if self.raw_data:
            return self.raw_data[0]
        elif self.data is not None:
            return unicode(self.data)
        else:
            return u''

    def process_formdata(self, valuelist):
        if valuelist:
            try:
                self.data = int(valuelist[0])
            except ValueError:
                raise ValueError(self.gettext(u'Not a valid integer value'))


class DecimalField(TextField):
    """
    A text field which displays and coerces data of the `decimal.Decimal` type.

    :param places:
        How many decimal places to quantize the value to for display on form.
        If None, does not quantize value.
    :param rounding:
        How to round the value during quantize, for example
        `decimal.ROUND_UP`. If unset, uses the rounding value from the
        current thread's context.
    """

    def __init__(self, label=u'', validators=None, places=2, rounding=None, **kwargs):
        super(DecimalField, self).__init__(label, validators, **kwargs)
        self.places = places
        self.rounding = rounding

    def _value(self):
        if self.raw_data:
            return self.raw_data[0]
        elif self.data is not None:
            if self.places is not None:
                if hasattr(self.data, 'quantize'):
                    exp = decimal.Decimal('.1') ** self.places
                    quantized = self.data.quantize(exp, rounding=self.rounding)
                    return unicode(quantized)
                else:
                    # If for some reason, data is a float or int, then format
                    # as we would for floats using string formatting.
                    format = u'%%0.%df' % self.places
                    return format % self.data
            else:
                return unicode(self.data)
        else:
            return u''

    def process_formdata(self, valuelist):
        if valuelist:
            try:
                self.data = decimal.Decimal(valuelist[0])
            except (decimal.InvalidOperation, ValueError):
                raise ValueError(self.gettext(u'Not a valid decimal value'))


class FloatField(TextField):
    """
    A text field, except all input is coerced to an float.  Erroneous input
    is ignored and will not be accepted as a value.
    """
    def __init__(self, label=u'', validators=None, **kwargs):
        super(FloatField, self).__init__(label, validators, **kwargs)

    def _value(self):
        if self.raw_data:
            return self.raw_data[0]
        elif self.data is not None:
            return unicode(self.data)
        else:
            return u''

    def process_formdata(self, valuelist):
        if valuelist:
            try:
                self.data = float(valuelist[0])
            except ValueError:
                raise ValueError(self.gettext(u'Not a valid float value'))


class BooleanField(Field):
    """
    Represents an ``<input type="checkbox">``.
    """
    widget = widgets.CheckboxInput()

    def __init__(self, label=u'', validators=None, **kwargs):
        super(BooleanField, self).__init__(label, validators, **kwargs)

    def process_data(self, value):
        self.data = bool(value)

    def process_formdata(self, valuelist):
        self.data = bool(valuelist)

    def _value(self):
        if self.raw_data:
            return unicode(self.raw_data[0])
        else:
            return u'y'


class DateTimeField(Field):
    """
    A text field which stores a `datetime.datetime` matching a format.
    """
    widget = widgets.TextInput()

    def __init__(self, label=u'', validators=None, format='%Y-%m-%d %H:%M:%S', **kwargs):
        super(DateTimeField, self).__init__(label, validators, **kwargs)
        self.format = format

    def _value(self):
        if self.raw_data:
            return u' '.join(self.raw_data)
        else:
            return self.data and self.data.strftime(self.format) or u''

    def process_formdata(self, valuelist):
        if valuelist:
            date_str = u' '.join(valuelist)
            try:
                timetuple = time.strptime(date_str, self.format)
                self.data = datetime.datetime(*timetuple[:6])
            except ValueError:
                self.data = None
                raise


class DateField(DateTimeField):
    """
    Same as DateTimeField, except stores a `datetime.date`.
    """
    def __init__(self, label=u'', validators=None, format='%Y-%m-%d', **kwargs):
        super(DateField, self).__init__(label, validators, format, **kwargs)

    def process_formdata(self, valuelist):
        if valuelist:
            date_str = u' '.join(valuelist)
            try:
                timetuple = time.strptime(date_str, self.format)
                self.data = datetime.date(*timetuple[:3])
            except ValueError:
                self.data = None
                raise


class SubmitField(BooleanField):
    """
    Represents an ``<input type="submit">``.  This allows checking if a given
    submit button has been pressed.
    """
    widget = widgets.SubmitInput()


class FormField(Field):
    """
    Encapsulate a form as a field in another form.

    :param form_class:
        A subclass of Form that will be encapsulated.
    :param separator:
        A string which will be suffixed to this field's name to create the
        prefix to enclosed fields. The default is fine for most uses.
    """
    widget = widgets.TableWidget()

    def __init__(self, form_class, label=u'', validators=None, separator='-', **kwargs):
        super(FormField, self).__init__(label, validators, **kwargs)
        self.form_class = form_class
        self.separator = separator
        self._obj = None
        if self.filters:
            raise TypeError('FormField cannot take filters, as the encapsulated data is not mutable.')
        if validators:
            raise TypeError('FormField does not accept any validators. Instead, define them on the enclosed form.')

    def process(self, formdata, data=_unset_value):
        if data is _unset_value:
            try:
                data = self.default()
            except TypeError:
                data = self.default
            self._obj = data

        prefix = self.name + self.separator
        if isinstance(data, dict):
            self.form = self.form_class(formdata=formdata, prefix=prefix, **data)
        else:
            self.form = self.form_class(formdata=formdata, obj=data, prefix=prefix)

    def validate(self, form, extra_validators=tuple()):
        if extra_validators:
            raise TypeError('FormField does not accept in-line validators, as it gets errors from the enclosed form.')
        return self.form.validate()

    def populate_obj(self, obj, name):
        candidate = getattr(obj, name, None)
        if candidate is None:
            if self._obj is None:
                raise TypeError('populate_obj: cannot find a value to populate from the provided obj or input data/defaults')
            candidate = self._obj
            setattr(obj, name, candidate)

        self.form.populate_obj(candidate)

    def __iter__(self):
        return iter(self.form)

    def __getitem__(self, name):
        return self.form[name]

    def __getattr__(self, name):
        return getattr(self.form, name)

    @property
    def data(self):
        return self.form.data

    @property
    def errors(self):
        return self.form.errors


class FieldList(Field):
    """
    Encapsulate an ordered list of multiple instances of the same field type,
    keeping data as a list.

    >>> authors = FieldList(TextField('Name', [validators.required()]))

    :param unbound_field:
        A partially-instantiated field definition, just like that would be
        defined on a form directly.
    :param min_entries:
        if provided, always have at least this many entries on the field,
        creating blank ones if the provided input does not specify a sufficient
        amount.
    :param max_entries:
        accept no more than this many entries as input, even if more exist in
        formdata.
    """
    widget=widgets.ListWidget()

    def __init__(self, unbound_field, label=u'', validators=None, min_entries=0,
                 max_entries=None, default=tuple(), **kwargs):
        super(FieldList, self).__init__(label, validators, default=default, **kwargs)
        if self.filters:
            raise TypeError('FieldList does not accept any filters. Instead, define them on the enclosed field.')
        if validators:
            raise TypeError('FieldList does not accept any validators. Instead, define them on the enclosed field.')
        assert isinstance(unbound_field, UnboundField), 'Field must be unbound, not a field class'
        self.unbound_field = unbound_field
        self.min_entries = min_entries
        self.max_entries = max_entries
        self.last_index = -1
        self._prefix = kwargs.get('_prefix', '')

    def process(self, formdata, data=_unset_value):
        self.entries = []
        if data is _unset_value or not data:
            try:
                data = self.default()
            except TypeError:
                data = self.default

        if formdata:
            indices = sorted(set(self._extract_indices(self.name, formdata)))
            if self.max_entries:
                indices = indices[:self.max_entries]

            idata = iter(data)
            for index in indices:
                try:
                    obj_data = idata.next()
                except StopIteration:
                    obj_data = _unset_value
                self._add_entry(formdata, obj_data, index=index)
        else:
            for obj_data in data:
                self._add_entry(formdata, obj_data)

        while len(self.entries) < self.min_entries:
            self._add_entry(formdata)

    def _extract_indices(self, prefix, formdata):
        """
        Yield indices of any keys with given prefix.

        formdata must be an object which will produce keys when iterated.  For
        example, if field 'foo' contains keys 'foo-0-bar', 'foo-1-baz', then
        the numbers 0 and 1 will be yielded, but not neccesarily in order.
        """
        offset = len(prefix) + 1
        for k in formdata:
            if k.startswith(prefix):
                k = k[offset:].split('-', 1)[0]
                if k.isdigit():
                    yield int(k)

    def validate(self, form, extra_validators=tuple()):
        self.errors = []
        success = True
        for subfield in self.entries:
            if not subfield.validate(form):
                success = False
                self.errors.append(subfield.errors)
        return success

    def populate_obj(self, obj, name):
        values = getattr(obj, name, None)
        try:
            ivalues = iter(values)
        except TypeError:
            ivalues = iter([])

        candidates = itertools.chain(ivalues, itertools.repeat(None))
        _fake = type('_fake', (object, ), {})
        output = []
        for field, data in itertools.izip(self.entries, candidates):
            fake_obj = _fake()
            fake_obj.data = data
            field.populate_obj(fake_obj, 'data')
            output.append(fake_obj.data)

        setattr(obj, name, output)

    def _add_entry(self, formdata=None, data=_unset_value, index=None):
        assert not self.max_entries or len(self.entries) < self.max_entries, \
            'You cannot have more than max_entries entries in this FieldList'
        new_index = self.last_index = index or (self.last_index + 1)
        name = '%s-%d' % (self.short_name, new_index)
        id   = '%s-%d' % (self.id, new_index)
        field = self.unbound_field.bind(form=None, name=name, prefix=self._prefix, id=id)
        field.process(formdata, data)
        self.entries.append(field)
        return field

    def append_entry(self, data=_unset_value):
        """
        Create a new entry with optional default data.

        Entries added in this way will *not* receive formdata however, and can
        only receive object data.
        """
        return self._add_entry(data=data)

    def pop_entry(self):
        """ Removes the last entry from the list and returns it. """
        entry = self.entries.pop()
        self.last_index -= 1
        return entry

    def __iter__(self):
        return iter(self.entries)

    def __len__(self):
        return len(self.entries)

    def __getitem__(self, index):
        return self.entries[index]

    @property
    def data(self):
        return [f.data for f in self.entries]