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我想创建一个Django模型字段，它表示持续时间与天，小时，分钟和秒文本输入字段在HTML中，并将持续时间存储在数据库中ical格式（RFC5545）。“对象没有任何属性”在自定义Django模型字段
（这关系到我的问题上How to create an ical duration field in Django?）
这里是我的方法：
感谢bakkal和波尔。以下是我想出的。
from django.db import models
from icalendar.prop import vDuration
from django.forms.widgets import MultiWidget
from django.forms import TextInput, IntegerField
from django.forms.util import flatatt
from django.forms.fields import MultiValueField
from django.utils.encoding import force_unicode
from django.utils.safestring import mark_safe
from django.utils.text import capfirst
from django.utils.translation import ugettext_lazy as _
from django.core import validators
from datetime import timedelta
def is_int(s):
try:
int(s)
return True
except ValueError:
return False
class Widget_LabelInputField(TextInput):
"""
Input widget with label
"""
input_type="numbers"
def __init__(self, labelCaption, attrs=None):
self.labelCaption = labelCaption
super(Widget_LabelInputField, self).__init__(attrs)
def _format_value(self, value):
if is_int(value):
return value
return '0'
def render(self, name, value, attrs=None):
if value is None:
value = '0'
final_attrs = self.build_attrs(attrs, type=self.input_type, name=name)
if value != '':
# Only add the 'value' attribute if a value is non-empty.
final_attrs['value'] = force_unicode(self._format_value(value))
if (self.labelCaption):
typeString = self.labelCaption + ': '
else:
typeString = ''
return mark_safe(u'' + typeString + '<input%s style=\'width: 30px; margin-right: 20px\'/>' % flatatt(final_attrs))
class Widget_DurationField(MultiWidget):
"""
A Widget that splits duration input into two <input type="text"> boxes.
"""
def __init__(self, attrs=None):
widgets = (Widget_LabelInputField(labelCaption='days', attrs=attrs),
Widget_LabelInputField(labelCaption='hours', attrs=attrs),
Widget_LabelInputField(labelCaption='minutes', attrs=attrs),
Widget_LabelInputField(labelCaption='seconds', attrs=attrs)
)
super(Widget_DurationField, self).__init__(widgets, attrs)
def decompress(self, value):
if value:
duration = vDuration.from_ical(value)
return [str(duration.days), str(duration.seconds // 3600), str(duration.seconds % 3600 // 60), str(duration.seconds % 60)]
return [None, None, None, None]
class Forms_DurationField(MultiValueField):
widget = Widget_DurationField
default_error_messages = {
'invalid_day': _(u'Enter a valid day.'),
'invalid_hour': _(u'Enter a valid hour.'),
'invalid_minute': _(u'Enter a valid minute.'),
'invalid_second': _(u'Enter a valid second.')
}
def __init__(self, *args, **kwargs):
errors = self.default_error_messages.copy()
if 'error_messages' in kwargs:
errors.update(kwargs['error_messages'])
fields = (
IntegerField(min_value=-9999, max_value=9999,
error_messages={'invalid': errors['invalid_day']},),
IntegerField(min_value=-9999, max_value=9999,
error_messages={'invalid': errors['invalid_hour']},),
IntegerField(min_value=-9999, max_value=9999,
error_messages={'invalid': errors['invalid_minute']},),
IntegerField(min_value=-9999, max_value=9999,
error_messages={'invalid': errors['invalid_second']},),
)
super(Forms_DurationField, self).__init__(fields, *args, **kwargs)
def compress(self, data_list):
if data_list:
if data_list[0] in validators.EMPTY_VALUES:
raise ValidationError(self.error_messages['invalid_day'])
if data_list[1] in validators.EMPTY_VALUES:
raise ValidationError(self.error_messages['invalid_hour'])
if data_list[2] in validators.EMPTY_VALUES:
raise ValidationError(self.error_messages['invalid_minute'])
if data_list[3] in validators.EMPTY_VALUES:
raise ValidationError(self.error_messages['invalid_second'])
return vDuration(timedelta(days=data_list[0],hours=data_list[1],minutes=data_list[2],seconds=data_list[3]))
return None
class Model_DurationField(models.Field):
description = "Duration"
def __init__(self, *args, **kwargs):
super(Model_DurationField, self).__init__(*args, **kwargs)
def db_type(self, connection):
return 'varchar(255)'
def get_internal_type(self):
return "Model_DurationField"
def to_python(self, value):
if isinstance(value, vDuration) or value is None:
return value
return vDuration.from_ical(value)
def get_prep_value(self, value):
return value.to_ical()
def formfield(self, **kwargs):
defaults = {
'form_class': Forms_DurationField,
'required': not self.blank,
'label': capfirst(self.verbose_name),
'help_text': self.help_text}
defaults.update(kwargs)
return super(Model_DurationField, self).formfield(**defaults)
它工作在以下型号：
class TestModel(models.Model):
ID = models.CharField(max_length=255)
start = models.DateTimeField(null=True)
#duration = models.CharField(max_length=255,null=True) commented out
otherDuration = duration.Model_DurationField(null=True)
但不是在这一个：
class TestModel(models.Model):
ID = models.CharField(max_length=255)
start = models.DateTimeField(null=True)
duration = models.CharField(max_length=255,null=True) # not commented out
otherDuration = duration.Model_DurationField(null=True)
我收到以下错误：
File "/somepath/models.py", line 5, in TestModel
otherDuration = duration.Model_DurationField(null=True)
AttributeError: 'CharField' object has no attribute 'Model_DurationField'
这让我为难...似乎python认为我的领域是一个前一个字段的属性，但仅限于CharField。有任何想法吗？
我有类似的问题。我将该视图命名为与该模型相同的内容。 – User