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Diffstat (limited to 'django/newforms/forms.py')
| -rw-r--r-- | django/newforms/forms.py | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/django/newforms/forms.py b/django/newforms/forms.py new file mode 100644 index 0000000000..e490d0d5f9 --- /dev/null +++ b/django/newforms/forms.py @@ -0,0 +1,169 @@ +""" +Form classes +""" + +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 DeclarativeFieldsMetaclass(type): + "Metaclass that converts Field attributes to a dictionary called 'fields'." + def __new__(cls, name, bases, attrs): + attrs['fields'] = dict([(name, attrs.pop(name)) for name, obj in attrs.items() if isinstance(obj, Field)]) + 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): # TODO: prefix stuff + self.data = data or {} + 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 clean(self): + if self.__errors is None: + self.full_clean() + return self.clean_data + + def errors(self): + "Returns an ErrorDict for self.data" + if self.__errors is None: + self.full_clean() + return self.__errors + + def is_valid(self): + """ + Returns True if the form has no errors. Otherwise, False. This exists + solely for convenience, so client code can use positive logic rather + than confusing negative logic ("if not form.errors()"). + """ + return not bool(self.errors()) + + def as_table(self): + "Returns this form rendered as an HTML <table>." + output = u'\n'.join(['<tr><td>%s:</td><td>%s</td></tr>' % (pretty_name(name), BoundField(self, field, name)) for name, field in self.fields.items()]) + return '<table>\n%s\n</table>' % output + + def as_ul(self): + "Returns this form rendered as an HTML <ul>." + output = u'\n'.join(['<li>%s: %s</li>' % (pretty_name(name), BoundField(self, field, name)) for name, field in self.fields.items()]) + return '<ul>\n%s\n</ul>' % output + + def as_table_with_errors(self): + "Returns this form rendered as an HTML <table>, with errors." + output = [] + if self.errors().get(NON_FIELD_ERRORS): + # Errors not corresponding to a particular field are displayed at the top. + output.append('<tr><td colspan="2"><ul>%s</ul></td></tr>' % '\n'.join(['<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('<tr><td colspan="2"><ul>%s</ul></td></tr>' % '\n'.join(['<li>%s</li>' % e for e in bf.errors])) + output.append('<tr><td>%s:</td><td>%s</td></tr>' % (pretty_name(name), bf)) + return '<table>\n%s\n</table>' % '\n'.join(output) + + def as_ul_with_errors(self): + "Returns this form rendered as an HTML <ul>, with errors." + output = [] + if self.errors().get(NON_FIELD_ERRORS): + # Errors not corresponding to a particular field are displayed at the top. + output.append('<li><ul>%s</ul></li>' % '\n'.join(['<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 = '<li>' + if bf.errors: + line += '<ul>%s</ul>' % '\n'.join(['<li>%s</li>' % e for e in bf.errors]) + line += '%s: %s</li>' % (pretty_name(name), bf) + output.append(line) + return '<ul>\n%s\n</ul>' % '\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() + 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. + return self.as_widget(self._field.widget) + + 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): + 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) |