datatracker/ietf/utils/fields.py
Jennifer Richards 08e953995a
feat: better reject null characters in forms (#7472)
* feat: subclass ModelMultipleChoiceField to reject nuls

* refactor: Use custom ModelMultipleChoiceField

* fix: handle value=None
2024-05-28 10:34:55 -05:00

373 lines
14 KiB
Python

# Copyright The IETF Trust 2012-2020, All Rights Reserved
# -*- coding: utf-8 -*-
import datetime
import json
import re
import jsonfield
import debug # pyflakes:ignore
from typing import Optional, Type # pyflakes:ignore
from django import forms
from django.db import models # pyflakes:ignore
from django.core.validators import ProhibitNullCharactersValidator, validate_email
from django.core.exceptions import ValidationError
from django.utils.dateparse import parse_duration
class MultiEmailField(forms.Field):
def to_python(self, value):
"Normalize data to a list of strings."
# Return an empty list if no input was given.
if not value:
return []
if isinstance(value, str):
values = value.split(',')
return [ x.strip() for x in values if x.strip() ]
else:
return value
def validate(self, value):
"Check if value consists only of valid emails."
# Use the parent's handling of required fields, etc.
super(MultiEmailField, self).validate(value)
for email in value:
validate_email(email)
def yyyymmdd_to_strftime_format(fmt):
translation_table = sorted([
("yyyy", "%Y"),
("yy", "%y"),
("mm", "%m"),
("m", "%-m"),
("MM", "%B"),
("M", "%b"),
("dd", "%d"),
("d", "%-d"),
], key=lambda t: len(t[0]), reverse=True)
res = ""
remaining = fmt
while remaining:
for pattern, replacement in translation_table:
if remaining.startswith(pattern):
res += replacement
remaining = remaining[len(pattern):]
break
else:
res += remaining[0]
remaining = remaining[1:]
return res
class DatepickerMedia:
"""Media definitions needed for Datepicker widgets"""
css = dict(all=('ietf/css/datepicker.css',))
js = ('ietf/js/datepicker.js',)
class DatepickerDateInput(forms.DateInput):
"""DateInput that uses the Bootstrap datepicker
The format must be in the Bootstrap datepicker format (yyyy-mm-dd, e.g.), not the
strftime format. The picker_settings argument is a dict of parameters for the datepicker,
converting their camelCase names to dash-separated lowercase names and omitting the
'data-date' prefix to the key.
"""
Media = DatepickerMedia
def __init__(self, attrs=None, date_format=None, picker_settings=None):
super().__init__(
attrs,
yyyymmdd_to_strftime_format(date_format),
)
self.attrs.setdefault('data-provide', 'datepicker')
self.attrs.setdefault('data-date-format', date_format)
self.attrs.setdefault("data-date-autoclose", "1")
self.attrs.setdefault('placeholder', date_format)
if picker_settings is not None:
for k, v in picker_settings.items():
self.attrs['data-date-{}'.format(k)] = v
class DatepickerSplitDateTimeWidget(forms.SplitDateTimeWidget):
"""Split datetime widget using Bootstrap datepicker
The format must be in the Bootstrap datepicker format (yyyy-mm-dd, e.g.), not the
strftime format. The picker_settings argument is a dict of parameters for the datepicker,
converting their camelCase names to dash-separated lowercase names and omitting the
'data-date' prefix to the key.
"""
Media = DatepickerMedia
def __init__(self, *, date_format='yyyy-mm-dd', picker_settings=None, **kwargs):
date_attrs = kwargs.setdefault('date_attrs', dict())
date_attrs.setdefault("data-provide", "datepicker")
date_attrs.setdefault("data-date-format", date_format)
date_attrs.setdefault("data-date-autoclose", "1")
date_attrs.setdefault("placeholder", date_format)
if picker_settings is not None:
for k, v in picker_settings.items():
date_attrs['data-date-{}'.format(k)] = v
super().__init__(date_format=yyyymmdd_to_strftime_format(date_format), **kwargs)
class DatepickerDateField(forms.DateField):
"""DateField with some glue for triggering JS Bootstrap datepicker"""
def __init__(self, date_format, picker_settings=None, *args, **kwargs):
strftime_format = yyyymmdd_to_strftime_format(date_format)
kwargs["input_formats"] = [strftime_format]
kwargs["widget"] = DatepickerDateInput(dict(placeholder=date_format), date_format, picker_settings)
super(DatepickerDateField, self).__init__(*args, **kwargs)
# This accepts any ordered combination of labelled days, hours, minutes, seconds
ext_duration_re = re.compile(
r'^'
r'(?:(?P<days>-?\d+) ?(?:d|days))?'
r'(?:[, ]*(?P<hours>-?\d+) ?(?:h|hours))?'
r'(?:[, ]*(?P<minutes>-?\d+) ?(?:m|minutes))?'
r'(?:[, ]*(?P<seconds>-?\d+) ?(?:s|seconds))?'
r'$'
)
# This requires hours and minutes, and accepts optional X days and :SS
mix_duration_re = re.compile(
r'^'
r'(?:(?P<days>-?\d+) ?(?:d|days)[, ]*)?'
r'(?:(?P<hours>-?\d+))'
r'(?::(?P<minutes>-?\d+))'
r'(?::(?P<seconds>-?\d+))?'
r'$'
)
def parse_duration_ext(value):
if value.strip() != '':
match = ext_duration_re.match(value)
if not match:
match = mix_duration_re.match(value)
if not match:
return parse_duration(value)
else:
kw = match.groupdict()
kw = {k: float(v) for k, v in kw.items() if v is not None}
return datetime.timedelta(**kw)
class DurationField(forms.DurationField):
def to_python(self, value):
if value in self.empty_values:
return None
if isinstance(value, datetime.timedelta):
return value
value = parse_duration_ext(value)
if value is None:
raise ValidationError(self.error_messages['invalid'], code='invalid')
return value
class Select2Multiple(forms.SelectMultiple):
class Media:
css = {
'all': (
'ietf/css/select2.css',
)
}
js = (
'ietf/js/select2.js',
)
class SearchableField(forms.MultipleChoiceField):
"""Base class for searchable fields
The field uses a comma-separated list of primary keys in a CharField element as its
API with some extra attributes used by the Javascript part.
When used in a form, the template rendering that form must include the form's media.
This is done by putting {{ form.media }} in a header block. If CSS and JS should be
separated for the template, use {{ form.media.css }} and {{ form.media.js }} instead.
To make a usable subclass, you must fill in the model (either as a class-scoped variable
or in the __init__() method before calling the superclass __init__()) and define
the make_select2_data() and ajax_url() methods. You likely want to provide a more
specific default_hint_text as well.
"""
widget = Select2Multiple
# model = None # must be filled in by subclass
model = None # type:Optional[Type[models.Model]]
# max_entries = None # may be overridden in __init__
max_entries = None # type: Optional[int]
min_search_length = None # type: Optional[int]
default_hint_text = 'Type a value to search'
def __init__(self, hint_text=None, *args, **kwargs):
assert self.model is not None
self.hint_text = hint_text if hint_text is not None else self.default_hint_text
# Pop max_entries out of kwargs - this distinguishes passing 'None' from
# not setting the parameter at all.
if 'max_entries' in kwargs:
self.max_entries = kwargs.pop('max_entries')
if 'min_search_length' in kwargs:
self.min_search_length = kwargs.pop('min_search_length')
super(SearchableField, self).__init__(*args, **kwargs)
self.widget.attrs["class"] = "select2-field"
self.widget.attrs["data-placeholder"] = self.hint_text
if self.max_entries is not None:
self.widget.attrs["data-max-entries"] = self.max_entries
if self.min_search_length is not None:
self.widget.attrs["data-min-search-length"] = self.min_search_length
def make_select2_data(self, model_instances):
"""Get select2 data items
Should return an array of dicts, each with at least 'id' and 'text' keys.
"""
raise NotImplementedError('Must implement make_select2_data')
def ajax_url(self):
"""Get the URL for AJAX searches
Doing this in the constructor is difficult because the URL patterns may not have been
fully constructed there yet.
"""
raise NotImplementedError('Must implement ajax_url')
def get_model_instances(self, item_ids):
"""Get model instances corresponding to item identifiers in select2 field value
Default implementation expects identifiers to be model pks. Return value is an iterable.
"""
return self.model.objects.filter(pk__in=item_ids)
def validate_pks(self, pks):
"""Validate format of PKs
Base implementation does nothing, but subclasses may override if desired.
Should raise a forms.ValidationError in case of a failed validation.
"""
pass
def describe_failed_pks(self, failed_pks):
"""Format error message to display when non-existent PKs are referenced"""
return ('Could not recognize the following {model_name}s: {pks}. '
'You can only input {model_name}s already registered in the Datatracker.'.format(
pks=', '.join(failed_pks),
model_name=self.model.__name__.lower())
)
def prepare_value(self, value):
if isinstance(value, list):
if len(value) == 0:
value = None
elif len(value) == 1:
value = value[0]
else:
if not isinstance(value[0], self.model):
value = self.get_model_instances(value)
if isinstance(value, int):
value = str(value)
if isinstance(value, str):
if value == "":
value = self.model.objects.none()
else:
value = self.get_model_instances([value])
if isinstance(value, self.model):
value = [value]
pre = self.make_select2_data(value)
for d in pre:
if isinstance(value, list):
d["selected"] = any([v.pk == d["id"] for v in value])
elif value:
d["selected"] = value.exists() and value.filter(pk__in=[d["id"]]).exists()
self.widget.attrs["data-pre"] = json.dumps(list(pre))
# doing this in the constructor is difficult because the URL
# patterns may not have been fully constructed there yet
ajax_url = self.ajax_url()
if ajax_url is not None:
self.widget.attrs["data-select2-ajax-url"] = ajax_url
result = value
return result
def clean(self, pks):
if pks is None:
return None
try:
objs = self.model.objects.filter(pk__in=pks)
except ValueError as e:
raise forms.ValidationError('Unexpected field value; {}'.format(e))
found_pks = [ str(o.pk) for o in objs ]
failed_pks = [ x for x in pks if x not in found_pks ]
if failed_pks:
raise forms.ValidationError(self.describe_failed_pks(failed_pks))
if self.max_entries != None and len(objs) > self.max_entries:
raise forms.ValidationError('You can select at most {} {}.'.format(
self.max_entries,
'entry' if self.max_entries == 1 else 'entries',
))
return objs.first() if self.max_entries == 1 else objs
def has_changed(self, initial, data):
# When max_entries == 1, we behave like a ChoiceField so initial will likely be a single
# value. Make it a list so MultipleChoiceField's has_changed() can work with it.
if initial is not None and self.max_entries == 1 and not isinstance(initial, (list, tuple)):
initial = [initial]
return super().has_changed(initial, data)
class IETFJSONField(jsonfield.fields.forms.JSONField):
def __init__(self, *args, empty_values=jsonfield.fields.forms.JSONField.empty_values,
accepted_empty_values=None, **kwargs):
if accepted_empty_values is None:
accepted_empty_values = []
self.empty_values = [x
for x in empty_values
if x not in accepted_empty_values]
super().__init__(*args, **kwargs)
class MissingOkImageField(models.ImageField):
"""Image field that can validate successfully if file goes missing
The default ImageField fails even to validate if its back-end file goes
missing, at least when width_field and height_field are used. This ignores
the exception that arises. Without this, even deleting a model instance
through a form fails.
"""
def update_dimension_fields(self, *args, **kwargs):
try:
super().update_dimension_fields(*args, **kwargs)
except FileNotFoundError:
pass # don't do anything if the file has gone missing
class ModelMultipleChoiceField(forms.ModelMultipleChoiceField):
"""ModelMultipleChoiceField that rejects null characters cleanly"""
validate_no_nulls = ProhibitNullCharactersValidator()
def clean(self, value):
try:
for item in value:
self.validate_no_nulls(item)
except TypeError:
# A TypeError probably means value is not iterable, which most commonly comes up
# with None as a value. If it's something more exotic, we don't know how to test
# for null characters anyway. Either way, trust the superclass clean() method to
# handle it.
pass
return super().clean(value)