from forms import Form from django.utils.encoding import StrAndUnicode from django.utils.safestring import mark_safe from django.utils.translation import ugettext as _ from fields import IntegerField, BooleanField from widgets import Media, HiddenInput from util import ErrorList, ValidationError __all__ = ('BaseFormSet', 'all_valid') # special field names TOTAL_FORM_COUNT = 'TOTAL_FORMS' INITIAL_FORM_COUNT = 'INITIAL_FORMS' ORDERING_FIELD_NAME = 'ORDER' DELETION_FIELD_NAME = 'DELETE' class ManagementForm(Form): """ ``ManagementForm`` is used to keep track of how many form instances are displayed on the page. If adding new forms via javascript, you should increment the count field of this form as well. """ def __init__(self, *args, **kwargs): self.base_fields[TOTAL_FORM_COUNT] = IntegerField(widget=HiddenInput) self.base_fields[INITIAL_FORM_COUNT] = IntegerField(widget=HiddenInput) super(ManagementForm, self).__init__(*args, **kwargs) class BaseFormSet(StrAndUnicode): """ A collection of instances of the same Form class. """ def __init__(self, data=None, files=None, auto_id='id_%s', prefix=None, initial=None, error_class=ErrorList): self.is_bound = data is not None or files is not None self.prefix = prefix or self.get_default_prefix() self.auto_id = auto_id self.data = data self.files = files self.initial = initial self.error_class = error_class self._errors = None self._non_form_errors = None # initialization is different depending on whether we recieved data, initial, or nothing if data or files: self.management_form = ManagementForm(data, auto_id=self.auto_id, prefix=self.prefix) if self.management_form.is_valid(): self._total_form_count = self.management_form.cleaned_data[TOTAL_FORM_COUNT] self._initial_form_count = self.management_form.cleaned_data[INITIAL_FORM_COUNT] else: raise ValidationError('ManagementForm data is missing or has been tampered with') else: if initial: self._initial_form_count = len(initial) if self._initial_form_count > self.max_num and self.max_num > 0: self._initial_form_count = self.max_num self._total_form_count = self._initial_form_count + self.extra else: self._initial_form_count = 0 self._total_form_count = self.extra if self._total_form_count > self.max_num and self.max_num > 0: self._total_form_count = self.max_num initial = {TOTAL_FORM_COUNT: self._total_form_count, INITIAL_FORM_COUNT: self._initial_form_count} self.management_form = ManagementForm(initial=initial, auto_id=self.auto_id, prefix=self.prefix) # construct the forms in the formset self._construct_forms() def __unicode__(self): return self.as_table() def _construct_forms(self): # instantiate all the forms and put them in self.forms self.forms = [] for i in xrange(self._total_form_count): self.forms.append(self._construct_form(i)) def _construct_form(self, i, **kwargs): """ Instantiates and returns the i-th form instance in a formset. """ defaults = {'auto_id': self.auto_id, 'prefix': self.add_prefix(i)} if self.data or self.files: defaults['data'] = self.data defaults['files'] = self.files if self.initial: try: defaults['initial'] = self.initial[i] except IndexError: pass # Allow extra forms to be empty. if i >= self._initial_form_count: defaults['empty_permitted'] = True defaults.update(kwargs) form = self.form(**defaults) self.add_fields(form, i) return form def _get_initial_forms(self): """Return a list of all the intial forms in this formset.""" return self.forms[:self._initial_form_count] initial_forms = property(_get_initial_forms) def _get_extra_forms(self): """Return a list of all the extra forms in this formset.""" return self.forms[self._initial_form_count:] extra_forms = property(_get_extra_forms) # Maybe this should just go away? def _get_cleaned_data(self): """ Returns a list of form.cleaned_data dicts for every form in self.forms. """ if not self.is_valid(): raise AttributeError("'%s' object has no attribute 'cleaned_data'" % self.__class__.__name__) return [form.cleaned_data for form in self.forms] cleaned_data = property(_get_cleaned_data) def _get_deleted_forms(self): """ Returns a list of forms that have been marked for deletion. Raises an AttributeError if deletion is not allowed. """ if not self.is_valid() or not self.can_delete: raise AttributeError("'%s' object has no attribute 'deleted_forms'" % self.__class__.__name__) # construct _deleted_form_indexes which is just a list of form indexes # that have had their deletion widget set to True if not hasattr(self, '_deleted_form_indexes'): self._deleted_form_indexes = [] for i in range(0, self._total_form_count): form = self.forms[i] # if this is an extra form and hasn't changed, don't consider it if i >= self._initial_form_count and not form.has_changed(): continue if form.cleaned_data[DELETION_FIELD_NAME]: self._deleted_form_indexes.append(i) return [self.forms[i] for i in self._deleted_form_indexes] deleted_forms = property(_get_deleted_forms) def _get_ordered_forms(self): """ Returns a list of form in the order specified by the incoming data. Raises an AttributeError if deletion is not allowed. """ if not self.is_valid() or not self.can_order: raise AttributeError("'%s' object has no attribute 'ordered_forms'" % self.__class__.__name__) # Construct _ordering, which is a list of (form_index, order_field_value) # tuples. After constructing this list, we'll sort it by order_field_value # so we have a way to get to the form indexes in the order specified # by the form data. if not hasattr(self, '_ordering'): self._ordering = [] for i in range(0, self._total_form_count): form = self.forms[i] # if this is an extra form and hasn't changed, don't consider it if i >= self._initial_form_count and not form.has_changed(): continue # don't add data marked for deletion to self.ordered_data if self.can_delete and form.cleaned_data[DELETION_FIELD_NAME]: continue # A sort function to order things numerically ascending, but # None should be sorted below anything else. Allowing None as # a comparison value makes it so we can leave ordering fields # blamk. def compare_ordering_values(x, y): if x[1] is None: return 1 if y[1] is None: return -1 return x[1] - y[1] self._ordering.append((i, form.cleaned_data[ORDERING_FIELD_NAME])) # After we're done populating self._ordering, sort it. self._ordering.sort(compare_ordering_values) # Return a list of form.cleaned_data dicts in the order spcified by # the form data. return [self.forms[i[0]] for i in self._ordering] ordered_forms = property(_get_ordered_forms) #@classmethod def get_default_prefix(cls): return 'form' get_default_prefix = classmethod(get_default_prefix) def non_form_errors(self): """ Returns an ErrorList of errors that aren't associated with a particular form -- i.e., from formset.clean(). Returns an empty ErrorList if there are none. """ if self._non_form_errors is not None: return self._non_form_errors return self.error_class() def _get_errors(self): """ Returns a list of form.errors for every form in self.forms. """ if self._errors is None: self.full_clean() return self._errors errors = property(_get_errors) def is_valid(self): """ Returns True if form.errors is empty for every form in self.forms. """ if not self.is_bound: return False # We loop over every form.errors here rather than short circuiting on the # first failure to make sure validation gets triggered for every form. forms_valid = True for errors in self.errors: if bool(errors): forms_valid = False return forms_valid and not bool(self.non_form_errors()) def full_clean(self): """ Cleans all of self.data and populates self._errors. """ self._errors = [] if not self.is_bound: # Stop further processing. return for i in range(0, self._total_form_count): form = self.forms[i] self._errors.append(form.errors) # Give self.clean() a chance to do cross-form validation. try: self.clean() except ValidationError, e: self._non_form_errors = e.messages def clean(self): """ Hook for doing any extra formset-wide cleaning after Form.clean() has been called on every form. Any ValidationError raised by this method will not be associated with a particular form; it will be accesible via formset.non_form_errors() """ pass def add_fields(self, form, index): """A hook for adding extra fields on to each form instance.""" if self.can_order: # Only pre-fill the ordering field for initial forms. if index < self._initial_form_count: form.fields[ORDERING_FIELD_NAME] = IntegerField(label=_(u'Order'), initial=index+1, required=False) else: form.fields[ORDERING_FIELD_NAME] = IntegerField(label=_(u'Order'), required=False) if self.can_delete: form.fields[DELETION_FIELD_NAME] = BooleanField(label=_(u'Delete'), required=False) def add_prefix(self, index): return '%s-%s' % (self.prefix, index) def is_multipart(self): """ Returns True if the formset needs to be multipart-encrypted, i.e. it has FileInput. Otherwise, False. """ return self.forms and self.forms[0].is_multipart() def _get_media(self): # All the forms on a FormSet are the same, so you only need to # interrogate the first form for media. if self.forms: return self.forms[0].media else: return Media() media = property(_get_media) def as_table(self): "Returns this formset rendered as HTML s -- excluding the
." # XXX: there is no semantic division between forms here, there # probably should be. It might make sense to render each form as a # table row with each field as a td. forms = u' '.join([form.as_table() for form in self.forms]) return mark_safe(u'\n'.join([unicode(self.management_form), forms])) def formset_factory(form, formset=BaseFormSet, extra=1, can_order=False, can_delete=False, max_num=0): """Return a FormSet for the given form class.""" attrs = {'form': form, 'extra': extra, 'can_order': can_order, 'can_delete': can_delete, 'max_num': max_num} return type(form.__name__ + 'FormSet', (formset,), attrs) def all_valid(formsets): """Returns true if every formset in formsets is valid.""" valid = True for formset in formsets: if not formset.is_valid(): valid = False return valid