class MultiValueField

from django.forms import MultiValueField
    Aggregate the logic of multiple Fields.

    Its clean() method takes a "decompressed" list of values, which are then
    cleaned into a single value according to self.fields. Each value in
    this list is cleaned by the corresponding field -- the first value is
    cleaned by the first field, the second value is cleaned by the second
    field, etc. Once all fields are cleaned, the list of clean values is
    "compressed" into a single value.

    Subclasses should not have to implement clean(). Instead, they must
    implement compress(), which takes a list of valid values and returns a
    "compressed" version of those values -- a single value.

    You'll probably want to use this with MultiWidget.
    

Ancestors (MRO)

  1. MultiValueField
  2. Field

Descendants

Attributes

  Defined in
default_error_messages = {'invalid': 'Enter a list of values.', 'incomplete': 'Enter a complete value.'} MultiValueField
default_error_messages = {'required': 'This field is required.'} Field
default_validators = [] Field
empty_values = [None, '', [], (), {}] Field
Expand Collapse

Methods

def bound_data(self, data, initial): Field

        Return the value that should be shown for this field on render of a
        bound form, given the submitted POST data for the field and the initial
        data, if any.

        For most fields, this will simply be data; FileFields need to handle it
        a bit differently.
        
    def bound_data(self, data, initial):
        """
        Return the value that should be shown for this field on render of a
        bound form, given the submitted POST data for the field and the initial
        data, if any.

        For most fields, this will simply be data; FileFields need to handle it
        a bit differently.
        """
        if self.disabled:
            return initial
        return data

def clean(self, value):

MultiValueField

        Validate every value in the given list. A value is validated against
        the corresponding Field in self.fields.

        For example, if this MultiValueField was instantiated with
        fields=(DateField(), TimeField()), clean() would call
        DateField.clean(value[0]) and TimeField.clean(value[1]).
        
    def clean(self, value):
        """
        Validate every value in the given list. A value is validated against
        the corresponding Field in self.fields.

        For example, if this MultiValueField was instantiated with
        fields=(DateField(), TimeField()), clean() would call
        DateField.clean(value[0]) and TimeField.clean(value[1]).
        """
        clean_data = []
        errors = []
        if not value or isinstance(value, (list, tuple)):
            if not value or not [v for v in value if v not in self.empty_values]:
                if self.required:
                    raise ValidationError(self.error_messages['required'], code='required')
                else:
                    return self.compress([])
        else:
            raise ValidationError(self.error_messages['invalid'], code='invalid')
        for i, field in enumerate(self.fields):
            try:
                field_value = value[i]
            except IndexError:
                field_value = None
            if field_value in self.empty_values:
                if self.require_all_fields:
                    # Raise a 'required' error if the MultiValueField is
                    # required and any field is empty.
                    if self.required:
                        raise ValidationError(self.error_messages['required'], code='required')
                elif field.required:
                    # Otherwise, add an 'incomplete' error to the list of
                    # collected errors and skip field cleaning, if a required
                    # field is empty.
                    if field.error_messages['incomplete'] not in errors:
                        errors.append(field.error_messages['incomplete'])
                    continue
            try:
                clean_data.append(field.clean(field_value))
            except ValidationError as e:
                # Collect all validation errors in a single list, which we'll
                # raise at the end of clean(), rather than raising a single
                # exception for the first error we encounter. Skip duplicates.
                errors.extend(m for m in e.error_list if m not in errors)
        if errors:
            raise ValidationError(errors)

        out = self.compress(clean_data)
        self.validate(out)
        self.run_validators(out)
        return out

Field

        Validate the given value and return its "cleaned" value as an
        appropriate Python object. Raise ValidationError for any errors.
        
    def clean(self, value):
        """
        Validate the given value and return its "cleaned" value as an
        appropriate Python object. Raise ValidationError for any errors.
        """
        value = self.to_python(value)
        self.validate(value)
        self.run_validators(value)
        return value

def compress(self, data_list): MultiValueField

        Return a single value for the given list of values. The values can be
        assumed to be valid.

        For example, if this MultiValueField was instantiated with
        fields=(DateField(), TimeField()), this might return a datetime
        object created by combining the date and time in data_list.
        
    def compress(self, data_list):
        """
        Return a single value for the given list of values. The values can be
        assumed to be valid.

        For example, if this MultiValueField was instantiated with
        fields=(DateField(), TimeField()), this might return a datetime
        object created by combining the date and time in data_list.
        """
        raise NotImplementedError('Subclasses must implement this method.')

def get_bound_field(self, form, field_name): Field

        Return a BoundField instance that will be used when accessing the form
        field in a template.
        
    def get_bound_field(self, form, field_name):
        """
        Return a BoundField instance that will be used when accessing the form
        field in a template.
        """
        return BoundField(form, self, field_name)

def has_changed(self, initial, data):

MultiValueField

    def has_changed(self, initial, data):
        if self.disabled:
            return False
        if initial is None:
            initial = ['' for x in range(0, len(data))]
        else:
            if not isinstance(initial, list):
                initial = self.widget.decompress(initial)
        for field, initial, data in zip(self.fields, initial, data):
            try:
                initial = field.to_python(initial)
            except ValidationError:
                return True
            if field.has_changed(initial, data):
                return True
        return False

Field

Return True if data differs from initial.
    def has_changed(self, initial, data):
        """Return True if data differs from initial."""
        # Always return False if the field is disabled since self.bound_data
        # always uses the initial value in this case.
        if self.disabled:
            return False
        try:
            data = self.to_python(data)
            if hasattr(self, '_coerce'):
                return self._coerce(data) != self._coerce(initial)
        except ValidationError:
            return True
        # For purposes of seeing whether something has changed, None is
        # the same as an empty string, if the data or initial value we get
        # is None, replace it with ''.
        initial_value = initial if initial is not None else ''
        data_value = data if data is not None else ''
        return initial_value != data_value

def prepare_value(self, value): Field

    def prepare_value(self, value):
        return value

def run_validators(self, value): Field

    def run_validators(self, value):
        if value in self.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:
                    e.message = self.error_messages[e.code]
                errors.extend(e.error_list)
        if errors:
            raise ValidationError(errors)

def to_python(self, value): Field

    def to_python(self, value):
        return value

def validate(self, value):

MultiValueField

    def validate(self, value):
        pass

Field

    def validate(self, value):
        if value in self.empty_values and self.required:
            raise ValidationError(self.error_messages['required'], code='required')

def widget_attrs(self, widget): Field

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