--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/forms/forms.py Tue Oct 14 16:00:59 2008 +0000
@@ -0,0 +1,422 @@
+"""
+Form classes
+"""
+
+from copy import deepcopy
+
+from django.utils.datastructures import SortedDict
+from django.utils.html import escape
+from django.utils.encoding import StrAndUnicode, smart_unicode, force_unicode
+from django.utils.safestring import mark_safe
+
+from fields import Field, FileField
+from widgets import Media, media_property, TextInput, Textarea
+from util import flatatt, ErrorDict, ErrorList, ValidationError
+
+__all__ = ('BaseForm', 'Form')
+
+NON_FIELD_ERRORS = '__all__'
+
+def pretty_name(name):
+ "Converts 'first_name' to 'First name'"
+ name = name[0].upper() + name[1:]
+ return name.replace('_', ' ')
+
+def get_declared_fields(bases, attrs, with_base_fields=True):
+ """
+ Create a list of form field instances from the passed in 'attrs', plus any
+ similar fields on the base classes (in 'bases'). This is used by both the
+ Form and ModelForm metclasses.
+
+ If 'with_base_fields' is True, all fields from the bases are used.
+ Otherwise, only fields in the 'declared_fields' attribute on the bases are
+ used. The distinction is useful in ModelForm subclassing.
+ Also integrates any additional media definitions
+ """
+ fields = [(field_name, attrs.pop(field_name)) for field_name, obj in attrs.items() if isinstance(obj, Field)]
+ fields.sort(lambda x, y: cmp(x[1].creation_counter, y[1].creation_counter))
+
+ # If this class is subclassing another Form, add that Form's fields.
+ # Note that we loop over the bases in *reverse*. This is necessary in
+ # order to preserve the correct order of fields.
+ if with_base_fields:
+ for base in bases[::-1]:
+ if hasattr(base, 'base_fields'):
+ fields = base.base_fields.items() + fields
+ else:
+ for base in bases[::-1]:
+ if hasattr(base, 'declared_fields'):
+ fields = base.declared_fields.items() + fields
+
+ return SortedDict(fields)
+
+class DeclarativeFieldsMetaclass(type):
+ """
+ Metaclass that converts Field attributes to a dictionary called
+ 'base_fields', taking into account parent class 'base_fields' as well.
+ """
+ def __new__(cls, name, bases, attrs):
+ attrs['base_fields'] = get_declared_fields(bases, attrs)
+ new_class = super(DeclarativeFieldsMetaclass,
+ cls).__new__(cls, name, bases, attrs)
+ if 'media' not in attrs:
+ new_class.media = media_property(new_class)
+ return new_class
+
+class BaseForm(StrAndUnicode):
+ # This is the main implementation of all the Form logic. Note that this
+ # class is different than Form. See the comments by the Form class for more
+ # information. Any improvements to the form API should be made to *this*
+ # class, not to the Form class.
+ def __init__(self, data=None, files=None, auto_id='id_%s', prefix=None,
+ initial=None, error_class=ErrorList, label_suffix=':',
+ empty_permitted=False):
+ self.is_bound = data is not None or files is not None
+ self.data = data or {}
+ self.files = files or {}
+ self.auto_id = auto_id
+ self.prefix = prefix
+ self.initial = initial or {}
+ self.error_class = error_class
+ self.label_suffix = label_suffix
+ self.empty_permitted = empty_permitted
+ self._errors = None # Stores the errors after clean() has been called.
+ self._changed_data = None
+
+ # The base_fields class attribute is the *class-wide* definition of
+ # fields. Because a particular *instance* of the class might want to
+ # alter self.fields, we create self.fields here by copying base_fields.
+ # Instances should always modify self.fields; they should not modify
+ # self.base_fields.
+ self.fields = deepcopy(self.base_fields)
+
+ def __unicode__(self):
+ return self.as_table()
+
+ def __iter__(self):
+ for name, field in self.fields.items():
+ yield BoundField(self, field, name)
+
+ def __getitem__(self, name):
+ "Returns a BoundField with the given name."
+ try:
+ field = self.fields[name]
+ except KeyError:
+ raise KeyError('Key %r not found in Form' % name)
+ return BoundField(self, field, name)
+
+ def _get_errors(self):
+ "Returns an ErrorDict for the data provided for the form"
+ if self._errors is None:
+ self.full_clean()
+ return self._errors
+ errors = property(_get_errors)
+
+ def is_valid(self):
+ """
+ Returns True if the form has no errors. Otherwise, False. If errors are
+ being ignored, returns False.
+ """
+ return self.is_bound and not bool(self.errors)
+
+ def add_prefix(self, field_name):
+ """
+ Returns the field name with a prefix appended, if this Form has a
+ prefix set.
+
+ Subclasses may wish to override.
+ """
+ return self.prefix and ('%s-%s' % (self.prefix, field_name)) or field_name
+
+ def add_initial_prefix(self, field_name):
+ """
+ Add a 'initial' prefix for checking dynamic initial values
+ """
+ return u'initial-%s' % self.add_prefix(field_name)
+
+ def _html_output(self, normal_row, error_row, row_ender, help_text_html, errors_on_separate_row):
+ "Helper function for outputting HTML. Used by as_table(), as_ul(), as_p()."
+ top_errors = self.non_field_errors() # Errors that should be displayed above all fields.
+ output, hidden_fields = [], []
+ for name, field in self.fields.items():
+ bf = BoundField(self, field, name)
+ bf_errors = self.error_class([escape(error) for error in bf.errors]) # Escape and cache in local variable.
+ if bf.is_hidden:
+ if bf_errors:
+ top_errors.extend([u'(Hidden field %s) %s' % (name, force_unicode(e)) for e in bf_errors])
+ hidden_fields.append(unicode(bf))
+ else:
+ if errors_on_separate_row and bf_errors:
+ output.append(error_row % force_unicode(bf_errors))
+ if bf.label:
+ label = escape(force_unicode(bf.label))
+ # Only add the suffix if the label does not end in
+ # punctuation.
+ if self.label_suffix:
+ if label[-1] not in ':?.!':
+ label += self.label_suffix
+ label = bf.label_tag(label) or ''
+ else:
+ label = ''
+ if field.help_text:
+ help_text = help_text_html % force_unicode(field.help_text)
+ else:
+ help_text = u''
+ output.append(normal_row % {'errors': force_unicode(bf_errors), 'label': force_unicode(label), 'field': unicode(bf), 'help_text': help_text})
+ if top_errors:
+ output.insert(0, error_row % force_unicode(top_errors))
+ if hidden_fields: # Insert any hidden fields in the last row.
+ str_hidden = u''.join(hidden_fields)
+ if output:
+ last_row = output[-1]
+ # Chop off the trailing row_ender (e.g. '</td></tr>') and
+ # insert the hidden fields.
+ if not last_row.endswith(row_ender):
+ # This can happen in the as_p() case (and possibly others
+ # that users write): if there are only top errors, we may
+ # not be able to conscript the last row for our purposes,
+ # so insert a new, empty row.
+ last_row = normal_row % {'errors': '', 'label': '', 'field': '', 'help_text': ''}
+ output.append(last_row)
+ output[-1] = last_row[:-len(row_ender)] + str_hidden + row_ender
+ else:
+ # If there aren't any rows in the output, just append the
+ # hidden fields.
+ output.append(str_hidden)
+ return mark_safe(u'\n'.join(output))
+
+ def as_table(self):
+ "Returns this form rendered as HTML <tr>s -- excluding the <table></table>."
+ return self._html_output(u'<tr><th>%(label)s</th><td>%(errors)s%(field)s%(help_text)s</td></tr>', u'<tr><td colspan="2">%s</td></tr>', '</td></tr>', u'<br />%s', False)
+
+ def as_ul(self):
+ "Returns this form rendered as HTML <li>s -- excluding the <ul></ul>."
+ return self._html_output(u'<li>%(errors)s%(label)s %(field)s%(help_text)s</li>', u'<li>%s</li>', '</li>', u' %s', False)
+
+ def as_p(self):
+ "Returns this form rendered as HTML <p>s."
+ return self._html_output(u'<p>%(label)s %(field)s%(help_text)s</p>', u'%s', '</p>', u' %s', True)
+
+ def non_field_errors(self):
+ """
+ Returns an ErrorList of errors that aren't associated with a particular
+ field -- i.e., from Form.clean(). Returns an empty ErrorList if there
+ are none.
+ """
+ return self.errors.get(NON_FIELD_ERRORS, self.error_class())
+
+ def full_clean(self):
+ """
+ Cleans all of self.data and populates self._errors and
+ self.cleaned_data.
+ """
+ self._errors = ErrorDict()
+ if not self.is_bound: # Stop further processing.
+ return
+ self.cleaned_data = {}
+ # If the form is permitted to be empty, and none of the form data has
+ # changed from the initial data, short circuit any validation.
+ if self.empty_permitted and not self.has_changed():
+ return
+ for name, field in self.fields.items():
+ # value_from_datadict() gets the data from the data dictionaries.
+ # Each widget type knows how to retrieve its own data, because some
+ # widgets split data over several HTML fields.
+ value = field.widget.value_from_datadict(self.data, self.files, self.add_prefix(name))
+ try:
+ if isinstance(field, FileField):
+ initial = self.initial.get(name, field.initial)
+ value = field.clean(value, initial)
+ else:
+ value = field.clean(value)
+ self.cleaned_data[name] = value
+ if hasattr(self, 'clean_%s' % name):
+ value = getattr(self, 'clean_%s' % name)()
+ self.cleaned_data[name] = value
+ except ValidationError, e:
+ self._errors[name] = e.messages
+ if name in self.cleaned_data:
+ del self.cleaned_data[name]
+ try:
+ self.cleaned_data = self.clean()
+ except ValidationError, e:
+ self._errors[NON_FIELD_ERRORS] = e.messages
+ if self._errors:
+ delattr(self, 'cleaned_data')
+
+ def clean(self):
+ """
+ Hook for doing any extra form-wide cleaning after Field.clean() been
+ called on every field. Any ValidationError raised by this method will
+ not be associated with a particular field; it will have a special-case
+ association with the field named '__all__'.
+ """
+ return self.cleaned_data
+
+ def has_changed(self):
+ """
+ Returns True if data differs from initial.
+ """
+ return bool(self.changed_data)
+
+ def _get_changed_data(self):
+ if self._changed_data is None:
+ self._changed_data = []
+ # XXX: For now we're asking the individual widgets whether or not the
+ # data has changed. It would probably be more efficient to hash the
+ # initial data, store it in a hidden field, and compare a hash of the
+ # submitted data, but we'd need a way to easily get the string value
+ # for a given field. Right now, that logic is embedded in the render
+ # method of each widget.
+ for name, field in self.fields.items():
+ prefixed_name = self.add_prefix(name)
+ data_value = field.widget.value_from_datadict(self.data, self.files, prefixed_name)
+ if not field.show_hidden_initial:
+ initial_value = self.initial.get(name, field.initial)
+ else:
+ initial_prefixed_name = self.add_initial_prefix(name)
+ hidden_widget = field.hidden_widget()
+ initial_value = hidden_widget.value_from_datadict(
+ self.data, self.files, initial_prefixed_name)
+ if field.widget._has_changed(initial_value, data_value):
+ self._changed_data.append(name)
+ return self._changed_data
+ changed_data = property(_get_changed_data)
+
+ def _get_media(self):
+ """
+ Provide a description of all media required to render the widgets on this form
+ """
+ media = Media()
+ for field in self.fields.values():
+ media = media + field.widget.media
+ return media
+ media = property(_get_media)
+
+ def is_multipart(self):
+ """
+ Returns True if the form needs to be multipart-encrypted, i.e. it has
+ FileInput. Otherwise, False.
+ """
+ for field in self.fields.values():
+ if field.widget.needs_multipart_form:
+ return True
+ return False
+
+class Form(BaseForm):
+ "A collection of Fields, plus their associated data."
+ # This is a separate class from BaseForm in order to abstract the way
+ # self.fields is specified. This class (Form) is the one that does the
+ # fancy metaclass stuff purely for the semantic sugar -- it allows one
+ # to define a form using declarative syntax.
+ # BaseForm itself has no way of designating self.fields.
+ __metaclass__ = DeclarativeFieldsMetaclass
+
+class BoundField(StrAndUnicode):
+ "A Field plus data"
+ def __init__(self, form, field, name):
+ self.form = form
+ self.field = field
+ self.name = name
+ self.html_name = form.add_prefix(name)
+ self.html_initial_name = form.add_initial_prefix(name)
+ if self.field.label is None:
+ self.label = pretty_name(name)
+ else:
+ self.label = self.field.label
+ self.help_text = field.help_text or ''
+
+ def __unicode__(self):
+ """Renders this field as an HTML widget."""
+ if self.field.show_hidden_initial:
+ return self.as_widget() + self.as_hidden(only_initial=True)
+ return self.as_widget()
+
+ def _errors(self):
+ """
+ Returns an ErrorList for this field. Returns an empty ErrorList
+ if there are none.
+ """
+ return self.form.errors.get(self.name, self.form.error_class())
+ errors = property(_errors)
+
+ def as_widget(self, widget=None, attrs=None, only_initial=False):
+ """
+ Renders the field by rendering the passed widget, adding any HTML
+ attributes passed as attrs. If no widget is specified, then the
+ field's default widget will be used.
+ """
+ if not widget:
+ widget = self.field.widget
+ attrs = attrs or {}
+ auto_id = self.auto_id
+ if auto_id and 'id' not in attrs and 'id' not in widget.attrs:
+ attrs['id'] = auto_id
+ if not self.form.is_bound:
+ data = self.form.initial.get(self.name, self.field.initial)
+ if callable(data):
+ data = data()
+ else:
+ data = self.data
+ if not only_initial:
+ name = self.html_name
+ else:
+ name = self.html_initial_name
+ return widget.render(name, data, attrs=attrs)
+
+ def as_text(self, attrs=None, **kwargs):
+ """
+ Returns a string of HTML for representing this as an <input type="text">.
+ """
+ return self.as_widget(TextInput(), attrs, **kwargs)
+
+ def as_textarea(self, attrs=None, **kwargs):
+ "Returns a string of HTML for representing this as a <textarea>."
+ return self.as_widget(Textarea(), attrs, **kwargs)
+
+ def as_hidden(self, attrs=None, **kwargs):
+ """
+ Returns a string of HTML for representing this as an <input type="hidden">.
+ """
+ return self.as_widget(self.field.hidden_widget(), attrs, **kwargs)
+
+ def _data(self):
+ """
+ Returns the data for this BoundField, or None if it wasn't given.
+ """
+ return self.field.widget.value_from_datadict(self.form.data, self.form.files, self.html_name)
+ data = property(_data)
+
+ def label_tag(self, contents=None, attrs=None):
+ """
+ Wraps the given contents in a <label>, if the field has an ID attribute.
+ Does not HTML-escape the contents. If contents aren't given, uses the
+ field's HTML-escaped label.
+
+ If attrs are given, they're used as HTML attributes on the <label> tag.
+ """
+ contents = contents or escape(self.label)
+ widget = self.field.widget
+ id_ = widget.attrs.get('id') or self.auto_id
+ if id_:
+ attrs = attrs and flatatt(attrs) or ''
+ contents = u'<label for="%s"%s>%s</label>' % (widget.id_for_label(id_), attrs, unicode(contents))
+ return mark_safe(contents)
+
+ def _is_hidden(self):
+ "Returns True if this BoundField's widget is hidden."
+ return self.field.widget.is_hidden
+ is_hidden = property(_is_hidden)
+
+ def _auto_id(self):
+ """
+ Calculates and returns the ID attribute for this BoundField, if the
+ associated Form has specified auto_id. Returns an empty string otherwise.
+ """
+ auto_id = self.form.auto_id
+ if auto_id and '%s' in smart_unicode(auto_id):
+ return smart_unicode(auto_id) % self.html_name
+ elif auto_id:
+ return self.html_name
+ return ''
+ auto_id = property(_auto_id)