django1/django/newforms/forms.py

199 lines
7.3 KiB
Python

"""
Form classes
"""
from django.utils.datastructures import SortedDict
from fields import Field
from widgets import TextInput, Textarea
from util import ErrorDict, ErrorList, ValidationError
NON_FIELD_ERRORS = '__all__'
def pretty_name(name):
"Converts 'first_name' to 'First name'"
name = name[0].upper() + name[1:]
return name.replace('_', ' ')
class SortedDictFromList(SortedDict):
"A dictionary that keeps its keys in the order in which they're inserted."
# This is different than django.utils.datastructures.SortedDict, because
# this takes a list/tuple as the argument to __init__().
def __init__(self, data=None):
if data is None: data = []
self.keyOrder = [d[0] for d in data]
dict.__init__(self, dict(data))
class DeclarativeFieldsMetaclass(type):
"Metaclass that converts Field attributes to a dictionary called 'fields'."
def __new__(cls, name, bases, attrs):
fields = [(name, attrs.pop(name)) for name, obj in attrs.items() if isinstance(obj, Field)]
fields.sort(lambda x, y: cmp(x[1].creation_counter, y[1].creation_counter))
attrs['fields'] = SortedDictFromList(fields)
return type.__new__(cls, name, bases, attrs)
class Form(object):
"A collection of Fields, plus their associated data."
__metaclass__ = DeclarativeFieldsMetaclass
def __init__(self, data=None, auto_id=False): # TODO: prefix stuff
self.ignore_errors = data is None
self.data = data or {}
self.auto_id = auto_id
self.clean_data = None # Stores the data after clean() has been called.
self.__errors = None # Stores the errors after clean() has been called.
def __str__(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 _errors(self):
"Returns an ErrorDict for self.data"
if self.__errors is None:
self.full_clean()
return self.__errors
errors = property(_errors)
def is_valid(self):
"""
Returns True if the form has no errors. Otherwise, False. If errors are
being ignored, returns False.
"""
return not self.ignore_errors and not bool(self.errors)
def as_table(self):
"Returns this form rendered as HTML <tr>s -- excluding the <table></table>."
output = []
if self.errors.get(NON_FIELD_ERRORS):
# Errors not corresponding to a particular field are displayed at the top.
output.append(u'<tr><td colspan="2"><ul>%s</ul></td></tr>' % u'\n'.join([u'<li>%s</li>' % e for e in self.errors[NON_FIELD_ERRORS]]))
for name, field in self.fields.items():
bf = BoundField(self, field, name)
if bf.errors:
output.append(u'<tr><td colspan="2"><ul>%s</ul></td></tr>' % u'\n'.join([u'<li>%s</li>' % e for e in bf.errors]))
output.append(u'<tr><td>%s:</td><td>%s</td></tr>' % (bf.label, bf))
return u'\n'.join(output)
def as_ul(self):
"Returns this form rendered as HTML <li>s -- excluding the <ul></ul>."
output = []
if self.errors.get(NON_FIELD_ERRORS):
# Errors not corresponding to a particular field are displayed at the top.
output.append(u'<li><ul>%s</ul></li>' % u'\n'.join([u'<li>%s</li>' % e for e in self.errors[NON_FIELD_ERRORS]]))
for name, field in self.fields.items():
bf = BoundField(self, field, name)
line = u'<li>'
if bf.errors:
line += u'<ul>%s</ul>' % u'\n'.join([u'<li>%s</li>' % e for e in bf.errors])
line += u'%s: %s</li>' % (bf.label, bf)
output.append(line)
return u'\n'.join(output)
def full_clean(self):
"""
Cleans all of self.data and populates self.__errors and self.clean_data.
"""
self.clean_data = {}
errors = ErrorDict()
if self.ignore_errors: # Stop further processing.
self.__errors = errors
return
for name, field in self.fields.items():
value = self.data.get(name, None)
try:
value = field.clean(value)
self.clean_data[name] = value
if hasattr(self, 'clean_%s' % name):
value = getattr(self, 'clean_%s' % name)()
self.clean_data[name] = value
except ValidationError, e:
errors[name] = e.messages
try:
self.clean_data = self.clean()
except ValidationError, e:
errors[NON_FIELD_ERRORS] = e.messages
if errors:
self.clean_data = None
self.__errors = errors
def clean(self):
"""
Hook for doing any extra form-wide cleaning after Field.clean() been
called on every field.
"""
return self.clean_data
class BoundField(object):
"A Field plus data"
def __init__(self, form, field, name):
self._form = form
self._field = field
self._name = name
def __str__(self):
"Renders this field as an HTML widget."
# Use the 'widget' attribute on the field to determine which type
# of HTML widget to use.
value = self.as_widget(self._field.widget)
if not isinstance(value, basestring):
# Some Widget render() methods -- notably RadioSelect -- return a
# "special" object rather than a string. Call the __str__() on that
# object to get its rendered value.
value = value.__str__()
return value
def _errors(self):
"""
Returns an ErrorList for this field. Returns an empty ErrorList
if there are none.
"""
try:
return self._form.errors[self._name]
except KeyError:
return ErrorList()
errors = property(_errors)
def as_widget(self, widget, attrs=None):
attrs = attrs or {}
auto_id = self.auto_id
if not attrs.has_key('id') and not widget.attrs.has_key('id') and auto_id:
attrs['id'] = auto_id
return widget.render(self._name, self._form.data.get(self._name, None), attrs=attrs)
def as_text(self, attrs=None):
"""
Returns a string of HTML for representing this as an <input type="text">.
"""
return self.as_widget(TextInput(), attrs)
def as_textarea(self, attrs=None):
"Returns a string of HTML for representing this as a <textarea>."
return self.as_widget(Textarea(), attrs)
def _label(self):
return pretty_name(self._name)
label = property(_label)
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 str(auto_id):
return str(auto_id) % self._name
elif auto_id:
return self._name
return ''
auto_id = property(_auto_id)