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[英]Change form field value in django, after __init__ but before cleaning
[英]Setting initial Django form field value in the __init__ method
姜戈 1.6
我在 Django 表單類中有一個工作代碼塊,如下所示。 我從中構建表單字段列表的數據集可以包含任何字段的初始值,但我在表單中設置該初始值沒有成功。 下面的if field_value:
塊確實填充了初始表單字典屬性,但未顯示初始值。 請注意(如果您想知道的話) .initial
屬性直到super()
調用之后才存在。
這能做到嗎?
如果是這樣,我做這項工作的不正確之處是什么?
謝謝!
def __init__(self, *args, **kwargs):
id = kwargs.pop('values_id', 0)
super(LaunchForm, self).__init__(*args, **kwargs)
# Lotsa code here that uses the id value
# to execute a query and build the form
# fields and their attributes from the
# result set
if field_value:
self.initial[field_name] = field_value
我遇到了完全相同的問題,我解決了這個問題:
def __init__(self, *args, **kwargs):
instance = kwargs.get('instance', None)
kwargs.update(initial={
# 'field': 'value'
'km_partida': '1020'
})
super(ViagemForm, self).__init__(*args, **kwargs)
# all other stuff
試試這個方法:
super(ViagemForm, self).__init__(*args, **kwargs)
if field_value:
#self.initial[field_name] = field_value
self.fields[field_name].initial = field_value
我想提一下,雖然這可能無法解決您的問題,但發送到表單的“初始”dict kwarg 似乎比field['field_name'].initial
受歡迎。
class MyView(View):
form = MyForm(initial={'my_field': 'first_value'})
class MyForm(Form):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.fields['my_field'].initial = 'second_value'
呈現的my_field
將初始設置為'first_value'
。
一些選項(除其他外)可能是:
在初始化表單之前確定second_value
中的second_value
:
class MyView(View):
# determine second_value here
form = MyForm(initial={'my_field': 'second_value'})
在調用super()
之前將first_value
替換為second_value
的initial
:
class MyForm(Form):
def __init__(self, *args, **kwargs):
# determine second_value here
if kwargs.get('initial', None):
kwargs['initial']['my_field'] = 'second_value'
super().__init__(*args, **kwargs)
在調用super()
之前確保'first_value'
不在kwargs['initial']
:
class MyForm(Form):
def __init__(self, *args, **kwargs):
if kwargs.get('initial', None):
if kwargs['initial']['my_field']
del(kwargs['initial']['my_field']
super().__init__(*args, **kwargs)
# determine second_value here
self.fields['my_field'].initial = 'second_value'
我在設置名為“needs_response”的單選按鈕的初始值時遇到了類似的問題,並通過檢查 self 的屬性並引用“declared_fields”來解決它:
# views.py
def review_feedback_or_question(request, template, *args, **kwargs):
if 'fqid' in kwargs:
fqid = kwargs['fqid']
submission = FeedbackQuestion.objects.get(pk=fqid)
form = FeedbackQuestionResponseForm(submission_type=submission.submission_type)
# other stuff
# forms.py
class FeedbackQuestionResponseForm(forms.Form):
CHOICES = (('1', 'Yes'), ('2', 'No'))
response_text = forms.CharField(
required=False,
label='',
widget=forms.Textarea(attrs={'placeholder': 'Enter response...'}))
needs_response = forms.ChoiceField(choices=CHOICES,
label='Needs response?',
widget=forms.RadioSelect())
def __init__(self, *args, **kwargs):
if 'submission_type' in kwargs:
submission_type = kwargs.pop('submission_type')
if submission_type == 'question':
self.declared_fields['needs_response'].initial = 1
else:
self.declared_fields['needs_response'].initial = 2
super(FeedbackQuestionResponseForm, self).__init__(*args, **kwargs)
這有效:
class BarForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.fields['state'] = forms.ChoiceField(
required=False,
choices=Foo.ADDRESS_STATE_CHOICES,
disabled='disabled',
initial='xyz',
)
state = forms.ChoiceField(
label='State',
choices=Foo.ADDRESS_STATE_CHOICES,
initial='foo',
)
在字段定義中使用initial= ""
將解決您的問題。 兩種建議的方法都是正確的,您只需要在字段定義中定義initial= ""
解決問題
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