parts/django/django/forms/formsets.py
changeset 307 c6bca38c1cbf
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parts/django/django/forms/formsets.py	Sat Jan 08 11:20:57 2011 +0530
@@ -0,0 +1,346 @@
+from forms import Form
+from django.core.exceptions import ValidationError
+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
+
+__all__ = ('BaseFormSet', 'all_valid')
+
+# special field names
+TOTAL_FORM_COUNT = 'TOTAL_FORMS'
+INITIAL_FORM_COUNT = 'INITIAL_FORMS'
+MAX_NUM_FORM_COUNT = 'MAX_NUM_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)
+        self.base_fields[MAX_NUM_FORM_COUNT] = IntegerField(required=False, 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
+        # construct the forms in the formset
+        self._construct_forms()
+
+    def __unicode__(self):
+        return self.as_table()
+
+    def _management_form(self):
+        """Returns the ManagementForm instance for this FormSet."""
+        if self.data or self.files:
+            form = ManagementForm(self.data, auto_id=self.auto_id, prefix=self.prefix)
+            if not form.is_valid():
+                raise ValidationError('ManagementForm data is missing or has been tampered with')
+        else:
+            form = ManagementForm(auto_id=self.auto_id, prefix=self.prefix, initial={
+                TOTAL_FORM_COUNT: self.total_form_count(),
+                INITIAL_FORM_COUNT: self.initial_form_count(),
+                MAX_NUM_FORM_COUNT: self.max_num
+            })
+        return form
+    management_form = property(_management_form)
+
+    def total_form_count(self):
+        """Returns the total number of forms in this FormSet."""
+        if self.data or self.files:
+            return self.management_form.cleaned_data[TOTAL_FORM_COUNT]
+        else:
+            initial_forms = self.initial_form_count()
+            total_forms = initial_forms + self.extra
+            # Allow all existing related objects/inlines to be displayed,
+            # but don't allow extra beyond max_num.
+            if initial_forms > self.max_num >= 0:
+                total_forms = initial_forms
+            elif total_forms > self.max_num >= 0:
+                total_forms = self.max_num
+        return total_forms
+
+    def initial_form_count(self):
+        """Returns the number of forms that are required in this FormSet."""
+        if self.data or self.files:
+            return self.management_form.cleaned_data[INITIAL_FORM_COUNT]
+        else:
+            # Use the length of the inital data if it's there, 0 otherwise.
+            initial_forms = self.initial and len(self.initial) or 0
+            if initial_forms > self.max_num >= 0:
+                initial_forms = self.max_num
+        return initial_forms
+
+    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 initial 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)
+
+    def _get_empty_form(self, **kwargs):
+        defaults = {
+            'auto_id': self.auto_id,
+            'prefix': self.add_prefix('__prefix__'),
+            'empty_permitted': True,
+        }
+        if self.data or self.files:
+            defaults['data'] = self.data
+            defaults['files'] = self.files
+        defaults.update(kwargs)
+        form = self.form(**defaults)
+        self.add_fields(form, None)
+        return form
+    empty_form = property(_get_empty_form)
+
+    # 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 self._should_delete_form(form):
+                    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 ordering 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 self._should_delete_form(form):
+                    continue
+                self._ordering.append((i, form.cleaned_data[ORDERING_FIELD_NAME]))
+            # After we're done populating self._ordering, sort it.
+            # 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.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 _should_delete_form(self, form):
+        # The way we lookup the value of the deletion field here takes
+        # more code than we'd like, but the form's cleaned_data will
+        # not exist if the form is invalid.
+        field = form.fields[DELETION_FIELD_NAME]
+        raw_value = form._raw_value(DELETION_FIELD_NAME)
+        should_delete = field.clean(raw_value)
+        return should_delete
+
+    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
+        err = self.errors
+        for i in range(0, self.total_form_count()):
+            form = self.forms[i]
+            if self.can_delete:
+                if self._should_delete_form(form):
+                    # This form is going to be deleted so any of its errors
+                    # should not cause the entire formset to be invalid.
+                    continue
+            if bool(self.errors[i]):
+                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 = self.error_class(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 is not None and 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 <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=None):
+    """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