diff -r 6641e941ef1e -r ff1a9aa48cfd app/django/forms/formsets.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/forms/formsets.py	Tue Oct 14 16:00:59 2008 +0000
@@ -0,0 +1,289 @@
+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 'form'
+        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)
+
+    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[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 <tr>s -- excluding the <table></table>."
+        # 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